**296Defendant Juan Carlos Rodriguez was convicted of the first-degree murder of his estranged wife, Maria Magdelana Rodriguez, and sentenced to death. After careful consideration of defendant's challenges to his convictions and sentence in light of the record and the applicable law, we find no error in the proceedings leading to defendant's **297conviction and the jury's rejection of his intellectual disability defense.1 On the other hand, we conclude that the trial court erred by failing, acting ex mero motu , to submit the statutory mitigating circumstance enumerated in N.C.G.S. § 15A-2000(f)(6) ("[t]he capacity of the defendant to appreciate the criminality of his conduct or to conform his conduct to the requirements of law was impaired") to the jury at defendant's capital sentencing hearing. As a result, we vacate defendant's death sentence and remand this case to the Superior Court, Forsyth County, for a new capital sentencing hearing.
I. Factual Background
A. Substantive Facts
1. State's Evidence
Defendant and Ms. Rodriguez became emotionally involved with each other in late 1992. The couple married when Ms. Rodriguez was thirteen years old and defendant was sixteen or seventeen years old and had their first child when Ms. Rodriguez was fourteen years old. Unfortunately, defendant became physically and emotionally abusive towards Ms. Rodriguez following their marriage.
*15This pattern of domestic violence continued after the couple came to the United States.
On 11 October 2010, Ms. Rodriguez entered a domestic violence shelter with her three children because she could "no longer live with [her] husband" and did not "have anywhere else to go." At the time that she entered the shelter, Ms. Rodriguez noted on an intake form that defendant had threatened to kill her, controlled most of her daily activities, and was violently jealous of her. Although Ms. Rodriguez left the shelter on 19 October 2010, she returned on 29 October to retrieve certain medications that she had left at that location. During the 29 October visit to the domestic violence shelter, Ms. Rodriguez seemed "happy" and "optimistic" and told shelter personnel that, while she was "doing well" and while Mr. Rodriguez "ha[d] not tried to move back in," "she [wa]s struggling to find employment" and "need[ed] assistance with food." On the other hand, Ms. Rodriguez told her friend, Merlyn Rodriguez, on 17 November 2010, that she was afraid of defendant; that he had "told her that if they didn't get back together, he would kill her"; and that "he could get rid of her and just throw her in the river."
**298On 18 November 2010, defendant came to the couple's former apartment, which was located at 1828 Trellis Lane in Winston-Salem and in which Ms. Rodriguez and the children had resided following the couple's separation, and asked Ms. Rodriguez to speak with him privately in the master bedroom. After a few minutes, the Rodriguez children, who were listening to music in the living room, heard Ms. Rodriguez cry for help. Santos Estela Rodriguez, one of the couple's children, attempted to open the door to the master bedroom but found that it was locked.2 After failing to gain access to the master bedroom by using a knife, Santos Estela Rodriguez told defendant that she was going to call the police. Shortly thereafter, defendant emerged from the master bedroom with blood on his knuckles, feet, and clothes. As soon as Santos Estela Rodriguez entered the master bedroom and "saw her mother on the floor" "breathing really hard," defendant stated that Ms. Rodriguez had hurt herself on the furniture and that he was taking Ms. Rodriguez to the hospital. After hoisting Ms. Rodriguez over his shoulder, defendant carried her to his vehicle.
Several hours later, defendant returned to 1828 Trellis Lane without Ms. Rodriguez. Upon arriving at the apartment, defendant asked the children and the son of a neighbor to help him clean the blood stained carpeting in the master bedroom. Although Santos Estela Rodriguez called all of the nearby hospitals, she was never able to locate her mother. On the following morning, 19 November 2010, defendant took the children to the home of his boss, Henry Ramirez, who lived in Eden. During the trip to Eden, Santos Estela Rodriguez observed the presence of blood in defendant's vehicle. A subsequent examination of defendant's vehicle by investigating officers revealed the presence of vomitus on the rear floorboard on the driver's side and blood on the interior of the rear driver's side door jamb, the back portion of the rear seat, a tan shirt located upon the upper portion of the rear seat, the rear floor mat on the driver's side, and the spare tire cover in the trunk.
At the time that investigating officers searched the apartment at 1828 Trellis Lane, they noticed that the premises were in disarray and that cleaning products could be found throughout the residence. "[A] large pool of blood or a large stain of what appeared to be blood [could be seen] on [the] carpet." According to another investigating officer, the carpet in the master bedroom "was discolored a pinkish color" and **299"frayed as though it had been scrubbed." Additional blood spatter patterns could be observed in the master bedroom as well.
At about 11:30 p.m. on 18 November 2010, Merlyn Rodriguez's sister, Zoila Rodriguez, began receiving messages from Ms. Rodriguez's phone. The messages received from Ms. Rodriguez's phone stated that:
Soyla, I went with my secret boyfriend to Spain. Carlos does not know. If he calls, *16tell him the truth and take care of the children. I met him three months ago. Cut the phone off because it doesn't work in the airport. Good-bye. I will call you from Spain. ... I don't have a charge anymore. Good-bye. Cut the telephone off. Later, I will fix it. I will call you from there.
Although Ms. Rodriguez knew how to spell Zoila Rodriguez's name, defendant later spelled Zoila's name as "Soyla" while conversing with investigating officers.
On 19 November 2010, Merlyn Rodriguez attempted to telephone Ms. Rodriguez on several occasions. However, each of Merlyn Rodriguez's calls went unanswered. After ascertaining that Ms. Rodriguez was not in her apartment, Merlyn Rodriguez called defendant, who initially told Merlyn Rodriguez that he did not know where Ms. Rodriguez was before stating that Ms. Rodriguez had "[s]tepped out of the house that night" and "never came back" and finally telling Merlyn Rodriguez that Ms. Rodriguez had "had an accident that night" and "was at the hospital."
Following her conversation with defendant, Merlyn Rodriguez called the police. Officer L.N. Williams of the Winston-Salem Police Department responded to Merlyn Rodriguez's missing person report, entered Ms. Rodriguez's apartment, and determined that she was not there. At that point, Officer Williams obtained defendant's phone number from Merlyn Rodriguez and called defendant for the purpose of inquiring into Ms. Rodriguez's whereabouts. Defendant told Officer Williams that Ms. Rodriguez had gone for a walk and did not return. After ascertaining that Ms. Rodriguez was not at work or at a local shelter and that the Rodriguez children were not in school, investigating officers began treating this matter as a high-risk missing person's case.
Defendant spent the night of 19 November 2010 with his pastor, David Agueda, in Martinsville, Virginia. On the following morning, while leading Saturday services, Pastor Agueda learned that investigating officers were looking for defendant and Ms. Rodriguez. Upon obtaining this information, Pastor Agueda advised defendant to turn himself in.
**300At approximately 7:00 p.m. on 19 November 2010, Lieutenant Steven Tollie of the Winston-Salem Police Department reclassified the case as a homicide and assigned it to Detective Stanley Nieves. After investigating officers located defendant on 21 November 2010, he was taken to Eden to be interviewed by Detective Nieves. In response to Detective Nieves's request that he describe the events that had occurred on 18 November 2010 at the 1828 Trellis Lane apartment, defendant stated that Ms. Rodriguez had told him that she was a lesbian and no longer wanted to be with him, that Ms. Rodriguez had hit her head against the dresser while lunging at him, and that Ms. Rodriguez had called for help after falling to the floor. At that point, defendant assisted Ms. Rodriguez in her efforts to get up, carried her to his car, and began to drive her to the hospital. As he did so, Ms. Rodriguez told defendant to stop, left the vehicle, and walked out of defendant's sight. Although Detective Nieves repeatedly accused defendant of having killed Ms. Rodriguez and having knowledge of the location at which Ms. Rodriguez's body could be found, defendant repeatedly denied Detective Nieves's accusations.
On the afternoon of 12 December 2010, which was a "very cold, damp" day featuring light snow and misty rain, investigating officers received a report that a decapitated body had been discovered in an area near 5020 Williamsburg Road in Winston-Salem that was "overgrown with small bushy pines" about "40 to 50 feet to the west of the asphalt area." Fingerprint information obtained from the body established that it was that of Ms. Rodriguez. On 29 May 2013, a human skull, later determined to be that of Ms. Rodriguez through the use of DNA analysis, was found in a wooded area near Belews Lake in rural Forsyth County.
According to Patrick Lantz, M.D., who autopsied the body, Ms. Rodriguez was in the early stages of decomposition at the time that her body was discovered. Dr. Lantz observed "maggot activity around the incision on the skin," incision marks around her clavicle, and a number of bruises all over her body characteristic of defensive wounds." Dr. Lantz opined that "the cause of death was *17manual strangulation," that Ms. Rodriguez had been decapitated after her death, and that, while there was "not exactly" "a scientific way to determine a postmortem interval," he believed, based upon information that he had received from investigating officers concerning the date upon which Ms. Rodriguez had last been seen alive and the observations that he had made during the autopsy and at the location at which the body had been discovered, that Ms. Rodriguez had died on 18 November 2010 and that the postmortem interval "was consistent with her being out there for three and a half weeks, or 24 days." **3012. Defendant's Evidence
Although she acknowledged that a forensic pathologist would be better qualified than she was to make such a determination, Dr. Ann Ross, a forensic anthropologist, concluded that Ms. Rodriguez 's abdominal area showed no signs of greening, which appears early in the putrefaction process. In addition, Dr. Ross believed that the crime scene and autopsy photographs suggested that Ms. Rodriguez "was still in the fresh state" of decomposition at the time that her body was found given the absence of significant marbling or maggot masses. According to Dr. Ross, "the remains of the decedent were in a fresh state" and had "not been out in the environmental conditions before December 1." Similarly, Thomas L. Bennett, M.D., a forensic pathologist, was of the opinion that "the most probable time frame" "is that [Ms.] Rodriguez was dead between three and seven days or so prior to her body being found on December 12th."
B. Intellectual Disability
1. Defendant's Life History
Defendant was born on 11 November 1974 in the Usulutan Department of El Salvador. Defendant and his family left the Usulutan Department "somewhere between 1979 and 1982" "because of the guerillas, who were the leftist fighters in the civil war in El Salvador." Defendant's family ultimately settled in Anchila, a location that was believed to be safe, when defendant was a child. However, the guerillas "began to occupy the area across the river from Anchila" after the Rodriguez family arrived at that location.
The Rodriguez home in Anchila was a "one-room hut[ ] with dirt floors. The walls were made out of sticks and mud." Although the roof was made out of "grass or tin," "there[ was] no solid wall" or "security to speak of." "[D]uring the rainy season, the floods would flood through the house," exposing the family "to all kinds of bacteria, viruses, decaying animals, [and] human waste" from a nearby outhouse.
While in Anchila, defendant "didn't have access to medical care," did not "attend school of any kind," and experienced "[c]hronic hunger [as] a way of life." Upon reaching the age of nine, defendant was sent to live with an aunt in San Salvador, which was considered to be safer and to have less fighting than Anchila. While in San Salvador, defendant began to receive medical care and entered the first grade. After successfully completing the first grade while failing the second grade, defendant returned to Anchila to help his family and repeat the second grade when he was eleven or twelve years old.
**302At the time that defendant returned to Anchila, "the civil war was very much raging around the family." Defendant heard "shooting at night and [remembered] the family being on the floor in terror." "It was not uncommon for [the family] to see dead bodies along the way when they were walking to school" and to "hear bomb[s] blasting[ ] and shooting." When defendant was sixteen years old, his older brother, Jose Fermin, was killed by guerillas after joining the army. Defendant was responsible for retrieving his brother's body and bringing it to the family home. While he was still sixteen and in the seventh grade, defendant dropped out of school.
After Jose Fermin's death and defendant's marriage to Ms. Rodriguez, defendant relocated to the United States. Upon arriving in this country, defendant was granted asylum on the grounds that he had been "threatened by the guerillas" and was "[l]iving in constant fear" and received authorization to work. Although defendant's son, Fermin, remained in El Salvador with defendant's father, Ms. Rodriguez joined defendant in the United States, where the couple had three more *18children, Santos Estela, Juan Carlos, Jr., and Jonathan.
2. Expert Testimony
a. Defendant's Evidence
Dr. Selena Sermeno, an expert in the field of clinical psychology who specializes in issues involving El Salvadoran young people, testified that the "protective and risk factors" present in a child's life, coupled with "the presence of chronic violence and trauma and adversity" and "[f]actors such as poverty, malnutrition, poor health, falls, exposure to trauma, any form of traumatic event, [and] the presence of fear," affect the child's intellectual capabilities. According to Dr. Sermeno, the civil war that occurred in El Salvador during defendant's adolescence had a significant negative effect upon his cognitive development. Among other things, Dr. Sermeno observed that defendant's memory and communication skills were impaired, which is "a very classic symptom in children who are traumatized to that degree." Defendant struggled "to recall information in any kind of chronological sequential or linear format," was confused by numerical concepts, and answered questions in a very literal manner. In addition, defendant's exposure to dangerous pesticides and contaminated water caused him to suffer from frequent illnesses, for which he never received proper medical care. Dr. Sermeno believed that the existence of these adverse environmental conditions had a significant effect upon defendant's intellectual development as well.
**303According to Dr. Sermeno, defendant suffered from post-traumatic stress disorder and a mild intellectual disability. In support of the second of these two diagnoses, Dr. Sermeno pointed to the fact that defendant scored 61 on the third edition of the Wechsler Adult Intelligence Scale (WAIS-III). In Dr. Sermeno's view, defendant had particular difficulties with functional academic learning and communication skills, with these deficiencies having manifested themselves before defendant reached the age of eighteen. In addition, Dr. Sermeno's intellectual disability diagnosis also rested upon defendant's exposure to extreme poverty, severe malnutrition, constant violence, pesticides, educational obstacles, and inadequate health care. Finally, Dr. Sermeno believed that defendant's post-traumatic stress disorder made it difficult for him to express strong emotions through verbal communication and body language.
Moira Artigues, M.D., a general and forensic psychiatrist, testified that she had evaluated defendant's "developmental history and the impact that that may have had on him, as well as ... his affect and demeanor, his face and his manner, and to form opinions about that as well." Dr. Artigues analyzes whether a person has an intellectual disability by examining that person's "background information, in terms of poverty, malnutrition, deprivation, education resources, and medical resources," "[b]ecause lack in any of those can affect intellectual development in children." According to Dr. Artigues, severe trauma, like that associated with "growing up in a civil war, very poor, and malnourished, causes the brain to wire in a way that's not optimal, and it can certainly affect your IQ as a result of the faulty wiring." As a child in El Salvador, defendant lacked access to medical care, experienced nutritional deprivation, and had no educational stimulation until he reached the age of ten, all of which can affect an individual's brain development and contribute to the development of a low intelligence quotient. Moreover, the experience of growing up during a civil war can result in accumulated trauma over time which can, in turn, lead to the development of post-traumatic stress disorder. In Dr. Artigues's view, a child's attempts to cope "with this chronic trauma and extreme stress" can affect the child's brain development and intelligence quotient.
In Dr. Artigues's opinion, defendant was mildly intellectually disabled. In support of this assertion, Dr. Artigues considered the fact that defendant had to make six different attempts to pass his driver's license test after reaching the United States. In addition, Dr. Artiques noted that, while interviewing defendant, he failed to grasp abstract concepts and had difficulty relaying information in chronological order, both of which conditions, in Dr. Artigues's opinion, reflect the existence **304of an intellectual disability. Dr. Artigues testified that defendant learned how to be a brick mason by being shown measurements *19marked permanently on a yardstick rather than by utilizing mathematics, with this type of learning limitation being typical of persons suffering from a mild intellectual disability. According to Dr. Artigues, intellectually disabled individuals have the ability to drive motor vehicles, work, marry, and have children. Dr. Artigues believed that defendant's intellectual disability manifested itself before he turned eighteen years of age in light of defendant's school records, intelligence quotient test scores, the results achieved during defendant's psychological evaluations, and defendant's exposure to malnutrition, severe trauma, and poverty. In Dr. Artigues's view, defendant was significantly deficient in functional academics and communication skills. Finally, Dr. Artigues determined that defendant suffered from post-traumatic stress disorder given that he had been exposed to significant trauma during his life, reported having had intrusive thoughts about the traumatic events that he had experienced, and experienced certain specific triggering events.
Dr. Antonio Puente, a clinical neuropsychologist and professor of psychology at the University of North Carolina at Wilmington, conducted a neuropsychological evaluation of defendant. Dr. Puente testified that the fact that defendant had a full scale score of 61 on the Central American, Spanish language version of the WAIS-III placed defendant in the bottom one percentile of the population. In addition, Dr. Puente administered the Beta Test, Third Edition; the Comprehensive Test of Nonverbal Intelligence, Second Edition; and the Bateria Test, Third Edition, to defendant. According to Dr. Puente, the Beta test was developed to measure the intellectual abilities of individuals who lack a formal education. Defendant had a score of 65 on the Beta Test, a result that placed him in the bottom one percent of the population. Similarly, Dr. Puente testified that defendant's full-scale score of 53 on the Comprehensive Test of Nonverbal Intelligence placed him in the bottom percentile. Although the Bateria test does not produce an intelligence quotient score, it does generate an intellectual abilities number. Defendant's intellectual abilities score placed him in the second percentile from the bottom. According to Dr. Puente, mild intellectual disability involves an intelligence quotient of between 50 and 70.
Another sign of mild intellectual disability, in Dr. Puente's view, is the presence of only some of the skills that allow an individual to function in society. Dr. Puente undertook this portion of his analysis by examining defendant's school records, driving tests, and the opinions of knowledgeable persons concerning defendant's functional capabilities.
**305In addition, Dr. Puente administered sixteen additional neuropsychological tests to defendant, three of which were used to assess the reliability of defendant's responses and the adequacy of defendant's efforts during the testing process. According to Dr. Puente, defendant's test results did not reflect malingering and accurately demonstrated the extent of defendant's abilities. As a result, Dr. Puente testified that defendant has significant sub-average intellectual functioning; has deficient cognitive, social, and practical skills; and is significantly impaired in the areas of functional academics and communication skills, with all of these diagnostic criteria having manifested themselves before defendant attained the age of eighteen.
b. State's Evidence
Stephen Kramer, M.D., a forensic neuropsychiatrist and professor of psychiatry at Wake Forest Baptist Medical Center, testified on behalf of the State that the El Salvadoran school system, which is much less rigorous than the United States school system, grades students on a scale from one to ten, with five being the lowest passing score. According to Dr. Kramer, most of defendant's grades were in the six to seven range, a set of results that is inconsistent with the presence of mild intellectual disability. In addition, Dr. Kramer noted that defendant could perform the chores expected of similarly aged children, another fact that suggests that defendant did not suffer from mild intellectual disability. In a similar vein, Dr. Kramer noted that defendant had been able to find employment in the United States that paid more than the minimum wage and that he had been known to "motivate" his co-workers, with these facts also being inconsistent with a contention that defendant suffers from a mild intellectual disability. According *20to Dr. Kramer, other activities in which defendant engaged, including the payment of taxes, the maintenance of his immigration status, and his ability to obtain a driver's license, "show[ed that defendant had] a level of adaptive functioning beyond that [expected] for the deficits requisite for a diagnosis of" intellectual disability.
Dr. Kramer testified that Detective Nieves had described defendant's Spanish as grammatically correct and that defendant had used an appropriate volume when speaking with the detective. Dr. Kramer noted that defendant had received a number of visitors since the date of his incarceration, a fact that tends to suggest that defendant has a social network and demonstrates his adaptive abilities. Dr. Kramer considered defendant's request for a Spanish-to-English dictionary, a Bible, and a Spanish textbook while in pretrial detention to indicate that defendant has the apparent ability to read and desired to engage in **306that activity, with those attributes further tending to show that defendant has adaptive capabilities. On the other hand, Dr. Kramer, like Dr. Artigues, believed that defendant has difficulty understanding abstract concepts like confidentiality or privacy.
According to Dr. Kramer, Dr. Puente mischaracterized the results of defendant's Dot Counting Test, an instrument used to detect malingering, because defendant "did worse the second time he did the test and was way over the threshold for suspecting not giving full effort." Dr. Kramer noted that defendant was "overtly cooperative," had a normal mood range, spoke Spanish in a clear and distinct manner while exhibiting a regular rate and rhythm, and had no difficulty with the comprehension portion of the exam. In addition, while defendant could not identify the year, month, day of the week, or season, he was able to perform complex commands without difficulty. The fact that defendant could not name the months of the year was "astonishing" to Dr. Kramer given his belief that even a person with mild intellectual disability should be able to perform that task.
Dr. Kramer administered a variety of tests for the purpose of assessing defendant's mathematical abilities, visual and verbal memory, neurological functioning, and motor skills. According to Dr. Kramer, defendant's math skills were "horrible" and included "very bizarre" responses. While completing a "literal cancellation test," which required defendant to find all of the A s on a page while subject to certain time constraints, defendant missed some A s and worked very slowly, with the physical restraints to which defendant was subject and visual deficits which defendant experienced accounting for this aspect of his performance. Dr. Kramer determined that defendant has a score of less than one on the National Stressful Events Survey PTSD Short Scale Test, which indicated, according to Dr. Kramer, that the severity of defendant's reaction to stress was, at most, mild. Even so, Dr. Kramer diagnosed defendant as suffering from dysthymic disorder, which is a form of chronic depression, and post-traumatic stress disorder.
Dr. Kramer questioned whether defendant exhibited symptoms of significant sub-average intellectual functioning. Although the fact that defendant had lived in severe poverty and suffered from malnutrition might adversely affect his intelligence quotient scores, those factors do not appear to have actually impaired his intellectual capacity. In addition, Dr. Kramer testified that defendant's "school grades were not consistent with [those of] someone with mild intellectual disability." According to Dr. Kramer, defendant's only adaptive functioning deficiency involved functional academics. As a result, for all of these reasons, Dr. Kramer **307disagreed with Dr. Puente's diagnosis that defendant suffered from an intellectual disability.
c. Defendant's Rebuttal Evidence
Dr. John Olley, a professor at the University of North Carolina at Chapel Hill and a psychologist at the Carolina Institute for Developmental Disabilities, testified that, since a person with an intelligence quotient of between 55 and 70 can appropriately be diagnosed as mildly intellectually disabled and since defendant had a score of 61 on the WAIS-III, his intelligence quotient falls within the mildly intellectually disabled range. In Dr. Olley's view, approximately one-third of mildly intellectually disabled persons are able to obtain a driver's license or learner's permit. Dr. Olley asserted that "a person's accomplishments"
*21cannot "rule out" the existence of an intellectual disability given that such a "diagnosis is based on identifying deficits, not identifying strengths," and revolves around "a pattern of lifelong limitations." In addition, Dr. Olley stated that the American Association of Intellectual and Development Disabilities (AAIDD), which was formerly known as the American Association of Mental Retardation, believes that socioeconomic factors, such as malnutrition, poverty, and lack of access to early childhood education, are "causative or at least high-risk factors in the diagnosis of" intellectual disabilities. According to Dr. Olley, the AAIDD attributes intellectual disabilities to biological, behavioral, social, and educational factors, with the biological factor being present in only the more severe cases of intellectual disabilities and with the other factors contributing to less severe cases. In Dr. Olley's view, poverty can contribute to a diagnosis of intellectual disability.
3. Capital Sentencing
a. State's Evidence
According to Lieutenant Tollie, the Rodriguez children had initially been placed in foster care before going to live with Ms. Rodriguez 's father, who resides in Boston. Friends Anna and Merlyn Rodriguez described Ms. Rodriguez as a very loving and caring mother who took good care of her children and had been excited to begin a new job at McDonald's.
b. Defendant's Evidence
Defendant had not been cited for any disciplinary infractions during the period of time in which he was held in pretrial confinement. Defendant's father, Manuel Romero, who was handicapped, loves his son very much and needs his financial support. Similarly, defendant's **308sister, Ana Julia Romero, testified that she loves her brother very much, that defendant denied having done anything to Ms. Rodriguez, and that Ms. Rodriguez was a very nice person who loved defendant and had been a good wife. Juan Carlos Rodriguez and Estela Santos Rodriguez expressed the desire to continue to have a relationship with their father, stated that they loved and missed him, and described Ms. Rodriguez as a loving mother.
B. Procedural History
On 2 July 2012, the Forsyth County grand jury returned a bill of indictment charging defendant with assault with a deadly weapon inflicting serious injury and first-degree kidnapping. On 16 July 2012, the Forsyth County grand jury returned superseding indictments charging defendant with first-degree murder, assault with a deadly weapon inflicting serious injury, and first-degree kidnapping. The charges against defendant came on for trial before the trial court and a jury at the 3 February 2014 criminal session of the Superior Court, Forsyth County.
On 10 March 2014, the jury returned verdicts finding defendant guilty of first-degree murder on the basis of malice, premeditation, and deliberation and the felony murder rule using first-degree kidnapping as the predicate felony, assault with a deadly weapon inflicting serious injury, and first-degree kidnapping. After accepting the jury's verdict, the trial court convened a separate proceeding for the purpose of determining whether defendant is intellectually disabled as that term is currently used in N.C.G.S. § 15A-2005. On 14 March 2014, the jury returned a verdict finding that defendant was not exempt from the imposition of the death penalty based upon intellectual disability-related grounds. On 17 March 2014, defendant unsuccessfully moved to set aside the jury verdict with respect to the intellectual disability issue. On the same day, the sentencing phase of defendant's trial commenced.
On 21 March 2014, the jury returned a verdict determining that defendant had killed Ms. Rodriguez while engaged in the commission of a first-degree kidnapping. The jury did not find as mitigating circumstances that defendant lacked a significant history of prior criminal conduct, N.C.G.S. § 15A-2000(f)(1), or that defendant had murdered Ms. Rodriguez while under the influence of a mental or emotional disturbance, id . § 15A-2000(f)(2). In addition, the jury rejected all proposed nonstatutory mitigating circumstances and found that no other mitigating circumstances existed, id . 15A-2000(f)(9). Finally, the jury found that the aggravating *22circumstance was sufficiently substantial to call for the imposition of the death penalty. Based upon the jury's **309verdicts, the trial court arrested judgment with respect to defendant's first-degree kidnapping conviction and entered judgments sentencing defendant to death based upon his first-degree murder conviction and to a concurrent term of twenty-five to thirty-nine months imprisonment based upon his conviction for assault with a deadly weapon inflicting serious injury. Defendant noted an appeal to this Court from the trial court's judgments.3
II. Legal Analysis
A. Jury Selection
In his initial challenge to the trial court's judgments, defendant contends that the trial court deprived him of his state and federal constitutional right to a trial by a fair and impartial jury by prohibiting his trial counsel from questioning prospective jurors concerning their ability to follow the applicable law prohibiting the imposition of the death penalty upon an intellectually disabled person. More specifically, defendant contends that "[i]t was critically important that each juror be free of any bias regarding the exemption of [intellectually disabled] offenders from capital punishment that would prevent that juror from deciding the question of [intellectual disability] based on the clinical evidence in accordance with § 15A-2005," which provides that "no defendant who is [intellectually disabled] shall be sentenced to death." N.C.G.S. § 15A-2005 (2014). According to defendant, the jurors empaneled to hear and decide this case "were not made aware until the sentencing phase that they would need to make a determination of [intellectual disability] that could take the death penalty off the table" or questioned concerning their ability to follow the law governing the extent to which an intellectually disabled person is eligible for the imposition of the death penalty in violation of defendant's Sixth Amendment right "to ascertain whether the juror has any bias, opinion, or prejudice that would affect or control the fair determination by him of the issues to be tried," quoting Connors v. United States , 158 U.S. 408, 413, 15 S.Ct. 951, 953, 39 L.Ed. 1033, 1035 (1895), and citing Morgan v. Illinois , 504 U.S. 719, 727, 112 S.Ct. 2222, 2228-29, 119 L.Ed. 2d 492, 502 (1992).
The State contends, on the other hand, that the trial court did not abuse its discretion during the jury selection process by sustaining the State's objection to defendant's attempts to question prospective **310jurors concerning intellectual disability issues. Contrary to defendant's assertions, the trial court simply prohibited defendant from prefacing the questions that he sought to pose to prospective jurors concerning intellectual disability issues with general legal statements. In addition, the State contends that defendant was able to elicit the information that he sought to obtain by posing these questions based upon prospective jurors' answers to other questions that the trial court allowed defendant to pursue and statements that the trial court allowed defendant's trial counsel to make. Finally, the State notes that the trial court properly instructed the jury concerning the effect of a finding of intellectual disability upon the jury's ability to make a binding recommendation that defendant be sentenced to death at an appropriate point in the proceedings.
During the jury selection process, defendant's trial counsel told the trial court that defendant's "intent was to ask these jurors can they follow the law with regard to mental retardation" and that, in order to make an adequate inquiry into this subject, he would be required "to tell them a little bit about what the law is." In response, the trial judge stated that defendant would be allowed to inquire into jurors' ability to follow the applicable law and stated:
THE COURT: Just don't give editorial comments. I certainly understand you're going to be entitled-you can preface it as, "There may be a defense or evidence of alleged mental retardation in this case.
*23Will you be able to fairly consider it in this case?"
Is that-does that not get you what you want? ...
[DEFENSE COUNSEL]: It does. What I would like to say is that North Carolina does not allow .... for a defendant to get the death penalty if they're mentally retarded; does anybody on the panel have any issues with that law.
....
THE COURT: Does the State object to that line of questioning?
[PROSECUTOR]: Yes, Your Honor. We object to him prefacing it with what the state of the law is until the jury is instructed. ... Because we would contend it's going to be in dispute.
**311....
THE COURT: When we get to the jury instructions, I'll give them the law that applies to this particular case. You're going to be entitled to ask questions about any-
[DEFENSE COUNSEL]: And mental retardation is not a mitigating circumstance that decides, yes or no, death penalty. That's the weighing part of it. I don't want the jury confused that this is just another mitigating circumstance. It's the law that they have to first decide before they even get to that [procedure.]
THE COURT: I'm not inclined-
....
THE COURT: -to allow the defendant just to state general propositions of the law. You're absolutely going to be entitled to ask jurors questions, as we've already discussed, with regard to any alleged mental retardation evidence. ...
....
THE COURT: ... You can ask them if they can follow the law that the Court will give you with regard to mental retardation and the effect it may have as to any decisions in the case. "Can you follow the law fairly and impartially that the Judge will give you with regard to the law on mental retardation?"
... But I've told everybody that neither attorney should question the jurors about the law except to ask whether they will follow the law as given to you by the Court.
After the prospective jurors returned to the courtroom at the conclusion of this colloquy between the trial court and counsel for the parties, defendant's trial counsel stated, without objection, that "[m]ental retardation is a defense to the death penalty" and that "[m]ental retardation is defined, among other things, as having a low IQ" and, along with the prosecutor, asked prospective jurors numerous questions related to intellectual disability issues.
"The primary goal of the jury selection process is to ensure selection of a jury comprised only of persons who will render a fair and **312impartial verdict." State v. Locklear , 331 N.C. 239, 247, 415 S.E.2d 726, 731 (1992) (citation omitted). "Pursuant to N.C.G.S. § 15A-1214(c), counsel may question prospective jurors concerning their fitness or competency to serve as jurors to determine whether there is a basis to challenge for cause or whether to exercise a peremptory challenge." State v. Fullwood , 343 N.C. 725, 732, 472 S.E.2d 883, 886-87 (1996) (citing N.C.G.S. § 15A-1214(c) (1988), cert. denied , 520 U.S. 1122, 117 S.Ct. 1260, 137 L.Ed. 2d 339 (1997) ). As part of the jury selection process, the trial court must allow counsel an opportunity "to inquire into the ability of the prospective jurors to follow the law," with "questions designed to measure prospective jurors' ability to follow the law [being] within the [proper] context of voir dire ." State v. Wiley , 355 N.C. 592, 617, 565 S.E.2d 22, 40 (2002), cert. denied , 537 U.S. 1117, 123 S.Ct. 882, 154 L.Ed. 2d 795 (2003). On the other hand, "[t]he trial judge has broad discretion to regulate jury voir dire ." Fullwood , 343 N.C. at 732, 472 S.E.2d at 887 (citing State v. Lee , 335 N.C. 244, 268, 439 S.E.2d 547, 559, cert. denied , 513 U.S. 891, 115 S.Ct. 239, 130 L.Ed. 2d 162 (1994) ); see also State v. Locklear , 349 N.C. 118, 142, 505 S.E.2d 277, 291 (1998) (explaining that "the extent and manner of the inquiry [allowed to counsel] rests within the trial court's discretion"), cert. denied , 526 U.S. 1075, 119 S.Ct. 1475, 143 L.Ed. 2d 559 (1999). "In order for a defendant to show reversible error in the trial court's regulation of jury selection, a defendant *24must show that the court abused its discretion and that he was prejudiced thereby." Lee , 335 N.C. at 268, 439 S.E.2d at 559 (citations omitted). As a result, "the trial court's exercise of discretion in preventing a defendant from pursuing a relevant line of questioning" must "render[ ] the trial fundamentally unfair" in order for the defendant to be entitled to obtain relief on appeal to this Court. Fullwood , 343 N.C. at 732-33, 472 S.E.2d at 887 (citing, inter alia , Morgan , 504 U.S. at 730 n.5, 112 S.Ct. at 2230 n.5, 119 L.Ed. 2d at 503 n.5 ).
Although the trial court did inform defendant's trial counsel that they should limit their questioning of prospective jurors with respect to intellectual disability issues to inquiring whether the members of the jury "can follow the law as given to you by the Court," defendant was allowed, without any objection from the State, to explain to two different jury panels at a time when all of the prospective jurors were present that "[m]ental retardation is a defense to the death penalty." In addition, defendant's trial counsel asked prospective jurors about their prior experiences with intellectually disabled individuals, the extent of their familiarity with intelligence testing and adaptive skills functioning issues, their willingness to consider expert mental health testimony, and their willingness to follow the applicable law as embodied in the trial **313court's instructions. When considered in conjunction with the fact that defendant's trial counsel was allowed to tell the prospective jurors that "[m]ental retardation is a defense to the death penalty" and the common sense understanding of a "defense" as something that precludes a finding of guilt or the imposition of a particular punishment, the questions that defendant's trial counsel were allowed to pose to prospective jurors concerning their ability to follow the law with respect to the intellectual disability issue sufficed to permit defendant's trial counsel to determine whether specific jurors could fairly consider and follow the trial court's instructions concerning the issue of whether defendant should be exempted from the imposition of the death penalty on the basis of any intellectual disabilities from which he suffered. On the other hand, the specific question that defendant sought permission to pose to prospective jurors would have done little more than elicit the prospective jurors' opinions concerning the validity of the undisputed legal principle barring the imposition of the death penalty upon intellectually disabled individuals. As a result, we do not believe that the limitations that the trial court placed upon the ability of defendant's trial counsel to question prospective jurors concerning intellectual disability issues constituted an abuse of discretion or "render[ed] the trial fundamentally unfair." Fullwood , 343 N.C. at 732-33, 472 S.E.2d at 887.
B. Guilt-Innocence Proceeding Issues
1. Sufficiency of the Evidence
Secondly, defendant contends that the trial court erred by denying his motion to dismiss the first-degree murder charge that had been lodged against him because the State failed to present sufficient evidence to establish his identity as the perpetrator of Ms. Rodriguez's murder. In support of this contention, defendant asserts that, when a State's case is wholly dependent upon circumstantial evidence, reviewing courts examine the record evidence for "proof of motive, opportunity, capability, and identity" in order "to show that a particular person committed a particular crime," quoting State v. Bell , 65 N.C. App. 234, 238, 309 S.E.2d 464, 467 (1983), aff'd , 311 N.C. 299, 316 S.E.2d 72 (1984). Although defendant acknowledges that the record contains sufficient evidence to permit a rational juror to find that he had the capability and motive to commit first-degree murder, he contends that the State failed to elicit sufficient evidence to establish the necessary opportunity and identity. More specifically, defendant points to the expert testimony contained in the record suggesting that Ms. Rodriguez died much later than 18 November 2010 and argues that "the State lacked any eyewitness testimony or physical evidence establishing where and when the **314homicide occurred," with such evidence being "critical to establishing opportunity," citing State v. Scott , 296 N.C. 519, 522, 251 S.E.2d 414, 416-17 (1979). In response, the State contends that the evidence more than sufficed to establish that defendant murdered Ms. Rodriguez, with defendant's argument *25resting upon an interpretation of the evidence that is favorable to himself rather than to the State.
"In ruling on a motion to dismiss, the trial court need determine only whether there is substantial evidence of each essential element of the crime and that the defendant is the perpetrator." State v. Call , 349 N.C. 382, 417, 508 S.E.2d 496, 518 (1998) (citation omitted). "Substantial evidence is that amount of relevant evidence necessary to persuade a rational juror to accept a conclusion." State v. Mann , 355 N.C. 294, 301, 560 S.E.2d 776, 781 (citation omitted), cert. denied , 537 U.S. 1005, 123 S.Ct. 495, 154 L.Ed. 2d 403 (2002). "As to whether substantial evidence exists, the question for the trial court is not one of weight, but of the sufficiency of the evidence." Id . at 301, 560 S.E.2d at 781.
The evidence is to be considered in the light most favorable to the State; the State is entitled to every reasonable intendment and every reasonable inference to be drawn therefrom; contradictions and discrepancies are for the jury to resolve and do not warrant dismissal; and all of the evidence actually admitted, whether competent or incompetent, which is favorable to the State is to be considered by the court in ruling on the motion.
State v. Powell , 299 N.C. 95, 99, 261 S.E.2d 114, 117 (1980) (citations omitted). On the other hand, in the event that the evidence merely raises "a suspicion or conjecture as to either the commission of the offense or the identity of the defendant as the perpetrator, the motion to dismiss must be allowed." State v. Malloy , 309 N.C. 176, 179, 305 S.E.2d 718, 720 (1983) (citations omitted). "Circumstantial evidence may withstand a motion to dismiss and support a conviction even when the evidence does not rule out every hypothesis of innocence." State v. Stone , 323 N.C. 447, 452, 373 S.E.2d 430, 433 (1988).
First-degree murder "is the unlawful killing of another human being with malice and with premeditation and deliberation." State v. Bonney , 329 N.C. 61, 77, 405 S.E.2d 145, 154 (1991). "Premeditation and deliberation 'are not ordinarily subject to proof by direct evidence, but must generally be proved ... by circumstantial evidence.' " State v. Taylor , 337 N.C. 597, 607, 447 S.E.2d 360, 367 (1994) (alteration in original) (quoting State v. Williams , 308 N.C. 47, 68-69, 301 S.E.2d 335, 349, cert. denied , **315464 U.S. 865, 104 S.Ct. 202, 78 L.Ed. 2d 177 (1983) ).4 "Circumstances tending to prove that the killing was premeditated and deliberate include, but are not limited to:
(1) want of provocation on the part of the deceased; (2) the conduct and statements of the defendant before and after the killing; (3) threats and declarations of the defendant before and during the course of the occurrence giving rise to the death of the deceased; (4) ill-will or previous difficulty between the parties; (5) the dealing of lethal blows after the deceased has been felled and rendered helpless; and (6) evidence that the killing was done in a brutal manner.
Id . at 607, 447 S.E.2d at 367 (quoting Williams , 308 N.C. at 69, 301 S.E.2d at 349 ); see also State v. Trull , 349 N.C. 428, 448, 509 S.E.2d 178, 192 (1998) (concluding that the defendant's actions in destroying evidence and attempting to cover up his involvement in the murder "permit the inference that defendant acted with premeditation and deliberation"), cert. denied , 528 U.S. 835, 120 S.Ct. 95, 145 L.Ed. 2d 80 (1999) ; State v. Scott , 343 N.C. 313, 341, 471 S.E.2d 605, 622 (1996) (concluding that evidence tending to show, among other things, that the "[d]efendant lied to everyone about [the decedent's] whereabouts and did not call the police or emergency medical personnel" "was sufficient to show premeditation and deliberation"); State v. Richardson , 328 N.C. 505, 513, 402 S.E.2d 401, 406 (1991) (concluding that evidence that the defendant strangled the victim sufficed to show premeditation and deliberation).
The evidence elicited by the State at trial tended to show that defendant had a history of abusing Ms. Rodriguez, that defendant had threatened to kill Ms. Rodriguez and to *26dispose of her body, that defendant violently attacked Ms. Rodriguez on 18 November 2010, that defendant was the last person to see Ms. Rodriguez alive, that defendant had been seen in the general area in which Ms. Rodriguez's body had been discovered, that defendant had attempted to clean up the location at which he assaulted Ms. Rodriguez, that defendant sent text messages from Ms. Rodriguez's phone to Merlyn Rodriguez in an attempt to establish that Ms. Rodriguez had voluntarily left the area, that Ms. Rodriguez's clothing and blood were found in defendant's vehicle, that defendant made conflicting statements concerning the circumstances surrounding **316Ms. Rodriguez's disappearance to various people, and that the autopsy performed upon Ms. Rodriguez's body indicated, consistently with other evidence tending to show that blood was emanating from Ms. Rodriguez's nose as Mr. Rodriguez carried her away, that Ms. Rodriguez had aspirated blood prior to her death. Aside from the fact that the evidence contains ample support for the State's contention that defendant caused Ms. Rodriguez's death, "[t]hese facts permit the inference that defendant acted with premeditation and deliberation." Trull , 349 N.C. at 448, 509 S.E.2d at 192. As a result, the trial court did not err by denying defendant's motion to dismiss the first-degree murder charge for insufficiency of the evidence.
2. Admission of Evidence Concerning Dr. Kramer's Former Employment
Thirdly, defendant contends that the trial court erred by allowing the State to elicit, over objection, evidence that one of defendant's trial counsel had previously hired Dr. Kramer to testify on behalf of another client. In defendant's view, "[t]he State improperly vouched for Dr. Kramer's credibility by eliciting testimony that Dr. Kramer had been hired by Robert Campbell, one of Mr. Rodriguez's attorneys, to testify on behalf of a criminal defense client in another case and in highlighting the prior employment in its closing argument," with this error having been particularly prejudicial given that the State's opposition to defendant's claim to be exempt from the imposition of the death penalty on intellectual disability grounds rested solely upon the credibility of Dr. Kramer's opinion that defendant was not intellectually disabled. In response to defendant's assertion, the State contends that the challenged testimony was relevant to the issue of Dr. Kramer's lack of bias and that the trial court did not err by allowing its admission.
When conducting a cross-examination, a prosecutor may not "inject into questions 'his own knowledge, beliefs, and personal opinions not supported by the evidence.' " State v. Sanderson , 336 N.C. 1, 14, 442 S.E.2d 33, 41 (1994) (quoting State v. Britt , 288 N.C. 699, 711, 220 S.E.2d 283, 291 (1975) ); see also State v. Phillips , 240 N.C. 516, 527, 82 S.E.2d 762, 770 (1954) (opining that prosecuting attorneys cannot "place before the jury by argument, insinuating questions, or other means, incompetent and prejudicial matters not legally admissible in evidence"). A prosecutor does not improperly vouch for the credibility of a State's witness, or otherwise "inject" "his own knowledge, beliefs, and personal opinions" into questioning, Sanderson , 336 N.C. at 14, 442 S.E.2d at 41, by merely explaining why the jury should find a State's witness to be **317credible. State v. Bunning , 338 N.C. 483, 488-89, 450 S.E.2d 462, 464 (1994). "A witness may be [questioned concerning] any matter relevant to any issue in the case, including credibility." State v. Lewis , 365 N.C. 488, 494, 724 S.E.2d 492, 497 (2012) (quoting N.C.G.S. § 8C-1, Rule 611(b) (2011) ). "We have long held that evidence of bias is logically relevant to a witness' credibility ...." Id . at 494, 724 S.E.2d at 497 ; see also State v. Atkins , 349 N.C. 62, 83, 505 S.E.2d 97, 110 (1998) (concluding that "the State appropriately attempted to illustrate a potential source of witness bias, as revealed by the expert witness's own curriculum vitae "), cert. denied , 526 U.S. 1147, 119 S.Ct. 2025, 143 L.Ed. 2d 1036 (1999). If the record at trial "reveals significant discrepancies between the diagnosis made by defendant's ... expert and the diagnosis reached by the State's expert," "it [is] entirely proper to elicit testimony indicative of potential witness bias." Atkins , 349 N.C. at 83, 505 S.E.2d at 111. A prosecutor's decision to elicit evidence tending to *27show a lack of bias on the part of a State's witness does not constitute impermissible prosecutorial vouching. See Bunning , 338 N.C. at 489, 450 S.E.2d at 464 (concluding that "statements by the prosecuting attorney were more in the nature of giving reason why the jury should believe the State's evidence than that the prosecuting attorney was vouching for the credibility of the State's witnesses or for his own credibility").
As we have already noted, Dr. Kramer testified that he disagreed with Dr. Puente's determination that defendant suffers from a mild intellectual disability. In view of the "significant discrepancies between the diagnosis made by defendant's ... expert and the diagnosis reached by the State's expert," "it [is] entirely proper to elicit testimony indicative of potential witness bias," or the lack thereof. Atkins , 349 N.C. at 83, 505 S.E.2d at 111. The prosecutor's decision to elicit evidence to the effect that Dr. Kramer had previously performed work for one of defendant's trial counsel did not "inject" the prosecutor's personal opinions into defendant's intellectual capabilities. On the contrary, the evidence elicited in response to the relevant prosecutorial questions tended to show a lack of bias on the part of Dr. Kramer by demonstrating that he had previously worked on behalf of both the State and criminal defendants. Although the trial court might have been better advised to have exercised its discretionary authority pursuant to N.C.G.S. § 8C-1, Rule 403, to limit the scope of the prosecutor's inquiry to whether Dr. Kramer had previously worked for counsel representing criminal defendants in general rather than specifically identifying one of defendant's trial counsel as an attorney to whom Dr. Kramer had provided expert assistance, we are unable to say, given the record before us in this case, that the challenged testimony constituted impermissible prosecutorial vouching **318for Dr. Kramer's credibility or that the trial court erred by refusing to preclude the admission of the challenged testimony.
C. Intellectual Disability Proceeding
Next, defendant contends that he demonstrated that he suffers from an intellectual disability by a preponderance of the evidence and that the trial court erred by denying his motion to set aside the jury's verdict in the State's favor with respect to this issue. As defendant notes, he was required to prove that he had "significantly subaverage general intellectual functioning" and "significant limitations in adaptive functioning" that "was manifested before the age of 18," quoting N.C.G.S. § 15A-2005(a)(2), by a preponderance of the evidence in order to be found to be exempt from the imposition of the death penalty upon intellectual disability grounds, citing id . § 15A-2005(f). Defendant claims to have satisfied his burden of proof with respect to this issue given that three of his intelligence quotient scores were below 70, that three separate expert witnesses testified that he had significant limitations in at least two of the statutorily enumerated areas of adaptive functioning, and that each of defendant's experts testified that defendant's mild intellectual disability manifested itself before he reached the age of eighteen. According to defendant, the State's expert did little more than challenge the evidence tending to show that defendant exhibited subaverage intellectual functioning as "questionable" and agreed that defendant had an adaptive deficit in the area of functional academics. In response, the State contends that a reviewing court should not disturb a jury determination with respect to the issue of intellectual disability in the event that there is any competent evidence reasonably tending to support it and that the record provided ample support for the jury's determination that defendant had failed to establish that he should be exempt from the imposition of the death penalty on intellectual disability grounds.
A trial court's ruling with respect to a motion to set aside a jury verdict "will not be disturbed on appeal absent an abuse of discretion." State v. Batts , 303 N.C. 155, 162, 277 S.E.2d 385, 389 (1981) (citations omitted) (upholding the denial of a motion to set aside a verdict after finding that "[t]here was sufficient evidence to warrant submission of the case to the jury and to support its verdict"). According to well-established North Carolina law, "[t]he credibility of the *28witnesses, the weight of the testimony, and conflicts in the evidence are matters for the jury to consider and pass upon," State v. Alford , 329 N.C. 755, 761, 407 S.E.2d 519, 524 (1991) (citations omitted), with the reviewing court lacking any responsibility for "pass[ing] on the credibility of witnesses or to weigh[ing] the testimony," **319State v. Hanes , 268 N.C 335, 339, 150 S.E.2d 489, 492 (1966). Defendant's assertion that we should conduct a de novo review of the trial court's decision to refrain from setting aside the jury's verdict with respect to the intellectual disability issue amounts to a request that we reweigh the evidence and make our own factual findings on appeal, a task for which an appellate court like this one is not well suited. Although defendant did present sufficient evidence to support a determination that he should be deemed exempt from the imposition of the death penalty on intellectual disability grounds, the State presented expert testimony from Dr. Kramer tending to support a contrary determination. The relative credibility of the testimony offered by the various expert witnesses concerning the nature and extent of defendant's intellectual limitations was a matter for the jury rather than for this Court, particularly given that the burden of proof with respect to the intellectual disability issue rested upon defendant. In light of the fact that the record reveals the existence of a conflict in the evidence concerning the extent to which defendant was intellectually disabled for purposes of N.C.G.S. § 15A-2005, we are unable to conclude that the trial court abused its discretion by failing to set aside the jury's verdict in the State's favor with respect to that issue.5
D. Capital Sentencing Proceeding
Finally, defendant asserts that the trial court erred at defendant's capital sentencing proceeding by failing to instruct the jury with respect to the statutory mitigating factor enumerated in N.C.G.S. § 15A-2000(f)(6), which addresses the extent to which defendant's capacity to appreciate the criminality of his conduct or to conform his conduct to the law was impaired. According to defendant, the trial court must instruct the jury concerning whether a particular mitigating circumstance exists in the event that the record contains sufficient evidence to establish the **320existence of that mitigating circumstance, citing State v. Hurst , 360 N.C. 181, 197, 624 S.E.2d 309, 322, cert. denied , 549 U.S. 875, 127 S.Ct. 186, 166 L.Ed. 2d 131 (2006). According to defendant, the record contained ample evidence tending to show that that defendant's "capacity ... to appreciate the criminality of his conduct or to conform his conduct to the requirements of law was impaired," quoting N.C.G.S. § 15A-2000(f)(6), with the jury being entitled to find the existence of the statutory mitigating circumstance enumerated in N.C.G.S. § 15A-2000(f)(6) "even if a defendant has capacity to know right from wrong, to know that the act he committed was wrong, and to the know the nature and quality of the act," quoting State v. Johnson , 298 N.C. 47, 68, 257 S.E.2d 597, 613 (1979). More specifically, defendant contends that the record contains substantial evidence tending to show that defendant is intellectually disabled and suffers from post-traumatic stress disorder or another mental condition and that defendant killed Ms. Rodriguez in the course of a marital crisis characterized by emotional turmoil. Defendant asserts that "[t]he combination of subnormal *29intelligence, psychological disorders, and/or a breakdown in a relationship has often been held to support submission of both the (f)(2) and the (f)(6) statutory mitigating circumstances," citing, inter alia , State v. Fullwood , 329 N.C. 233, 404 S.E.2d 842 (1991) (concluding that the record contained substantial evidence tending to show the existence of the (f)(6) statutory mitigating circumstance given that an expert psychologist had testified that defendant had limited verbal abilities and suffered from low self-esteem); State v. Huff , 325 N.C. 1, 381 S.E.2d 635 (1989), vacated , 497 U.S. 1021, 110 S.Ct. 3266, 111 L.Ed. 2d 777 (1990), on remand , 328 N.C. 532, 402 S.E.2d 577 (1991) (concluding that the record contained sufficient evidence to support the submission of the (f)(6) statutory mitigating circumstance given that the defendant exhibited symptoms of paranoid schizophrenia and delusional thinking); State v. Stokes , 308 N.C. 634, 304 S.E.2d 184 (1983) (holding that the record contained sufficient evidence to support the submission of the (f)(6) statutory mitigating circumstance given the presence of evidence tending to show that the defendant had an intelligence quotient of 63, poor reading skills, an antisocial disorder, and a history of mental health problems).
In seeking to persuade us to reach a different result, the State argues that this Court has noted that the (f)(6) statutory mitigating circumstance
has only been found to be supported in cases where there was evidence, expert or lay, of some mental disorder, disease, or defect, or voluntary intoxication by alcohol or **321narcotic drugs, to the degree that it affected the defendant's ability to understand and control his actions.
State v. Kemmerlin , 356 N.C. 446, 479, 481, 573 S.E.2d 870, 893, 894 (2002) (concluding the trial court did not err by failing to submit the (f)(6) statutory mitigating circumstance even though a defense mental health expert diagnosed defendant with borderline personality disorder and major depressive disorder on the grounds that the expert also testified that these conditions "did not prevent defendant from appreciating the criminality of her conduct and controlling her conduct as required by law"). Moreover, the State asserts that this Court has concluded that a defendant's conduct in the time leading up to and following the murder "may demonstrate that he was aware that his acts were criminal." State v. Polke , 361 N.C. 65, 72, 638 S.E.2d 189, 194 (2006), cert. denied , 552 U.S. 836, 128 S.Ct. 70, 169 L.Ed. 2d 55 (2007). Although the record did contain evidence tending to show that defendant has subaverage intellectual functioning, suffers from post-traumatic stress disorder and chronic depression, and was in the midst of a marital crisis, the State argues that the record was devoid of any evidence that these conditions impaired his capacity "to appreciate the criminality of his conduct or to conform his conduct to the requirements of law," quoting N.C.G.S. § 15A-2000(f)(6), at the time that he murdered Ms. Rodriguez. On the contrary, according to the State, the evidence concerning defendant's conduct before and after the murder of Ms. Rodriguez demonstrated defendant's awareness that "his acts were criminal," quoting Polke , 361 N.C. at 72, 638 S.E.2d at 194. Finally, the State contends that any error that the trial court might have committed by failing to instruct the jury concerning the (f)(6) statutory mitigating circumstance was harmless given that "any such error did not prevent any juror from considering and giving weight to the mitigating evidence," quoting State v. Ward , 338 N.C. 64, 113, 449 S.E.2d 709, 736-37 (1994), cert. denied , 514 U.S. 1134, 115 S.Ct. 2014, 131 L.Ed. 2d 1013 (1995).
According to N.C.G.S. § 15A-2000(b), a trial judge is required to instruct the jury to consider any aggravating or mitigating circumstances which have adequate evidentiary support. N.C.G.S. § 15A-2000(b) (2017). For that reason, "a trial court has no discretion in determining whether to submit a mitigating circumstance when 'substantial evidence' in support of the circumstance has been presented." State v. Watts , 357 N.C. 366, 377, 584 S.E.2d 740, 748 (2003) (quoting State v. Fletcher , 354 N.C. 455, 477, 555 S.E.2d 534, 547 (2001), cert. denied , 537 U.S. 846, 123 S.Ct. 184, 154 L.Ed. 2d 73 (2002) ), cert. denied , 541 U.S. 944, 124 S.Ct. 1673, 158 L.Ed. 2d 370 (2004) ; see also **322State v. Williams , 350 N.C. 1, 10-11, 510 S.E.2d 626, 633 (1999) (explaining that "the trial court *30has no discretion" and that "the statutory mitigating circumstance must be submitted to the jury, without regard to the wishes of the State or the defendant," if the "evidence will support a rational jury finding" concerning the existence of the mitigating circumstance) (quoting State v. Smith , 347 N.C. 453, 469, 496 S.E.2d 357, 366, cert. denied , 525 U.S. 845, 119 S.Ct. 113, 142 L.Ed. 2d 91 (1998) ), cert. denied , 528 U.S. 880, 120 S.Ct. 193, 145 L.Ed. 2d 162 (1999). "The test for determining if the evidence is 'substantial evidence' " to support an instruction for a statutory mitigating circumstance, "is 'whether a juror could reasonably find that the circumstance exists based on the evidence.' " Watts , 357 N.C. at 377, 584 S.E.2d at 748 (quoting Kemmerlin , 356 N.C. at 478, 573 S.E.2d at 892 (internal quotation marks omitted) ). As a result, "[e]ven if the defendant does not request the submission of the [statutory] mitigator or objects to its submission, the trial court must submit the circumstance when it is supported by sufficient evidence," State v. Cummings , 361 N.C. 438, 471, 648 S.E.2d 788, 808 (2007) (citations omitted), cert. denied , 552 U.S. 1319, 128 S.Ct. 1888, 170 L.Ed. 2d 760 (2008), with "any reasonable doubt regarding the submission of a statutory or requested mitigating factor [to] be resolved in favor of the defendant," State v. Phillips , 365 N.C. 103, 146, 711 S.E.2d 122, 152 (2011) (quoting State v. Brown , 315 N.C. 40, 62, 337 S.E.2d 808, 825 (1985), cert. denied , 476 U.S. 1164, 106 S.Ct. 2293, 90 L.Ed. 2d 733 (1986), overruled on other grounds by State v. Vandiver , 321 N.C. 570, 364 S.E.2d 373 (1988) ), cert. denied , 565 U.S. 1204, 132 S.Ct. 1541, 182 L.Ed. 2d 176 (2012). In other words, the actual fact-finding decision must, under the procedures outlined in North Carolina's capital sentencing statutes, be made by the jury rather than the trial or a reviewing court. "[F]ailure to submit a statutory mitigating circumstance that is supported by sufficient evidence is prejudicial error unless the State can demonstrate that the error was harmless beyond a reasonable doubt." Hurst , 360 N.C. at 194, 624 S.E.2d at 320 (citation omitted).
N.C.G.S. § 15A-2000(f)(6) creates a statutory mitigating circumstance applicable to situations in which "[t]he capacity of the defendant to appreciate the criminality of his conduct or to conform his conduct to the requirements of law was impaired." N.C.G.S. § 15A-2000(f)(6) (2017). The (f)(6) statutory mitigating circumstance
may exist even if a defendant has capacity to know right from wrong, to know that the act he committed was wrong, and to know the nature and quality of that act. It would exist even under these circumstances if the defendant's capacity to appreciate (to fully comprehend or be fully **323sensible of) the criminality (wrongfulness) of his conduct was impaired (lessened or diminished), or if defendant's capacity to follow the law and refrain from engaging in the illegal conduct was likewise impaired (lessened or diminished).
State v. Johnson , 298 N.C 355, 375, 259 S.E.2d 752, 764 (1979). Evidence, "expert or lay, of some mental disorder, disease, or defect ... to the degree that it affected the defendant's ability to understand and control his actions" supports submission of the (f)(6) statutory mitigating circumstance. Kemmerlin , 356 N.C. at 479, 573 S.E.2d at 893 (quoting State v. Syriani , 333 N.C. 350, 395, 428 S.E.2d 118, 142-43, cert. denied , 510 U.S. 948, 114 S.Ct. 392, 126 L.Ed. 2d 341 (1993) ). Even "[i]f the jury determines that the defendant does not have an intellectual disability as defined by [ N.C.G.S. § 15A-2005 ], the jury may consider any evidence of intellectual disability presented during the sentencing hearing when determining aggravating or mitigating factors and the defendant's sentence." N.C.G.S. § 15A-2005(g) (2017), see also Bobby v. Bies , 556 U.S. 825, 829, 129 S.Ct. 2145, 2149, 173 L.Ed. 2d 1173, 1178-79 (2009) (explaining that "mental retardation for purposes of Atkins [v. Virginia ], and mental retardation as one mitigator to be weighed against aggravators, are discrete issues").
In Fullwood , this Court found that the record contained "substantial evidence to support [the (f)(6) ] statutory mitigating circumstance," including expert testimony tending to show that the defendant's intelligence was between "low normal" and "retarded," that the defendant "suffered from very low feelings of self-esteem and 'inadequate personality,'
*31" that the defendant's "ability to understand and be understood through words was severely limited," and that the defendant was suffering from emotional anguish at the time that he committed the murder at issue in that case. 329 N.C. at 237, 404 S.E.2d at 844. Among other things, the expert witness upon whose testimony we relied in concluding that the record supported the submission of the (f)(6) statutory mitigating circumstance in Fullwood stated that "the stress from [the defendant's] poor relationship with his lover and child affected the defendant's limited intellectual resources to the extent that the defendant's judgment was very poor at the moment of the crime." Id. at 237, 404 S.E.2d at 844. Similarly, we have also stated that the record contained sufficient evidence to support the submission of the (f)(6) statutory mitigating circumstance to the jury in light of the existence of evidence concerning the defendant's "impoverished skills," "chronic substance abuse," "poor impulse control," and "diminished capacity" resulting in the defendant's "failure to understand the consequences of his actions."
**324State v. Hooks , 353 N.C. 629, 641-42, 548 S.E.2d 501, 510 (2001), cert. denied , 534 U.S. 1155, 122 S.Ct. 1126, 151 L.Ed. 2d 1018 (2002).
The issue of whether the trial court should submit the (f)(6) statutory mitigating circumstance to the jury does not hinge upon the presence or absence of evidence tending to show that the defendant "was under the influence of a mental or emotional disorder or disturbance" "at the time of the killing." State v. Geddie , 345 N.C. 73, 102-03, 478 S.E.2d 146, 161 (1996) (ellipses in original) (finding that "[t]he use of the word 'disturbance' in the (f)(2) circumstance shows the General Assembly intended something more ... than mental impairment which is found in [the (f)(6) ] mitigating circumstance' "), cert. denied , 522 U.S. 825, 118 S.Ct. 86, 139 L.Ed. 2d 43 (1997) (quoting State v. Spruill , 320 N.C. 688, 696, 360 S.E.2d 667, 671 (1987), cert. denied , 486 U.S. 1061, 108 S.Ct. 2833, 100 L.Ed. 2d 934 (1988) ). For example, in State v. Stokes , this Court held that evidence tending to show that the defendant had a lengthy history of "mental problems," was "mildly retarded," and suffered from an "antisocial disorder," 308 N.C. at 655, 304 S.E.2d at 197, sufficed to support a jury determination "that defendant's capacity to fully comprehend the wrongfulness of his conduct was impaired or diminished" so as to require the trial court to "submit[ ] the mitigating circumstance set forth in G.S. 15A-2000(f)(6) to the sentencing jury," id . at 656, 304 S.E.2d at 197, even though the record also contained evidence tending to show that the defendant "was capable of distinguishing right from wrong at the time of the offenses were committed," id . at 654, 304 S.E.2d at 197.
The record before us in this case contains ample support for the submission of the (f)(6) statutory mitigating circumstance. As an initial matter, we note that the record contains considerable evidence tending to show that defendant suffered from an intellectual disability, with the relevant evidence including expert testimony that defendant had an average intelligence quotient score of 61, that this intelligence quotient score placed defendant in the lowest two percent of the population, that defendant's intellectual disability initially manifested itself before defendant reached the age of eighteen, and that defendant's intelligence level will remain constant throughout his life. In addition, the record contains ample evidence that defendant suffers from multiple deficiencies in adaptive functioning and that defendant's exposure to extreme poverty, severe malnutrition, constant violence, and harmful pesticides, coupled with his lack of formal education and access to meaningful health care, make it more likely that defendant suffers from an intellectual disability. As Dr. Puente noted, a defendant's diminished intellectual capabilities impair his or her reasoning capabilities. Secondly, the expert testimony **325contained in the present record contains near-unanimous support for the proposition that defendant suffers from an emotional disorder, such as dysthymic disorder (chronic depression) or post-traumatic stress disorder, and that defendant killed Ms. Rodriguez during a time of marital turmoil. As this Court indicated in State v. Greene , 329 N.C. 771, 777, 408 S.E.2d 185, 188 (1991), "an abnormally susceptible defendant" can be motivated "to commit murder" by emotional turmoil despite *32the fact that "a person of normal mental and emotional stability would likely have resolved [the situation] without such disastrous results." The evidence of defendant's mental limitations and disturbed and overwrought thinking supports a rational inference that defendant's ability to fully comprehend the wrongfulness of his conduct and to conform his conduct to the requirements of the law was adversely affected at the time that he murdered Ms. Rodriguez. Thus, the evidence contained in the record developed in this case, like the evidence that this Court considered in cases such as Stokes and Fullwood , more than suffices to permit a rational juror to conclude that defendant's capacity to appreciate the criminality of his conduct or to conform his conduct to the requirements of the law at the time that he murdered Ms. Rodriguez was impaired, so that the trial court erred by failing to submit the (f)(6) statutory mitigating circumstance to the jury.
The State's contention that the actions in which defendant engaged following the murder of Ms. Rodriguez establish defendant's awareness that his actions were wrongful rests upon a misapprehension of the nature and effect of the relevant statutory mitigating circumstance and the standard that the trial court should utilize in determining whether a particular mitigating circumstance should be submitted to the jury. In essence, the State's argument assumes that any recognition of the wrongfulness of his conduct on defendant's part suffices to preclude the necessity for the submission of the (f)(6) statutory mitigating circumstance. Aside from the fact that this aspect of the State's argument might be understood to require us to make a factual, rather than a sufficiency of the evidence, determination, a rational juror is entitled, as this Court recognized in Johnson , to find the existence of the (f)(6) statutory mitigating circumstance even if the defendant knew "right from wrong," understood "the nature and quality of [the] act," and "appreciate[d] ... the criminality" of the act at the time of the commission of the murder for which he or she is being sentenced. 298 N.C. at 375, 259 S.E.2d at 764. Although intellectually disabled and emotionally disturbed and overwrought individuals "frequently know the difference between right and wrong," "they have diminished capacities to understand and process information, to communicate, to abstract from mistakes, and learn **326from experience, to engage in logical reasoning, to control impulses, and to understand the reactions of others" "[b]ecause of their impairments." Atkins v. Virginia , 536 U.S. 304, 318, 122 S.Ct. 2242, 2250, 153 L.Ed. 2d 335, 348 (2002). As a result, even though the record in this case certainly contains evidence tending to suggest that, at some level, defendant understood the criminality of his conduct and attempted to undertake actions that were intended to avoid the consequences of his wrongful conduct, that fact does not obviate the necessity for the submission of the (f)(6) statutory mitigating circumstance given that the relevant legal test does not treat any recognition of wrongful conduct on the part of a defendant as sufficient to support the non-submission of the statutory mitigating circumstance in question.
The State's suggestion that defendant's failure to present explicit evidence that the mental and emotional conditions from which he suffered existed and affected his conduct at the time that he murdered Ms. Rodriguez is equally misplaced. As an initial matter, we note that, while such evidence is necessary to support a finding that the statutory mitigating circumstance enumerated in N.C.G.S. § 15A-2000(f)(2) exists, the same is not true with respect to the statutory mitigating circumstance enumerated in N.C.G.S. § 15A-2000(f)(6). See Geddie , 345 N.C. at 102, 478 S.E.2d at 161. Aside from the fact that Dr. Puente testified that defendant's intellectual limitations adversely affected his judgment at the time that he murdered Ms. Rodriguez, the evidence tending to show that defendant's intellectual disability had manifested itself before the time that defendant turned eighteen and the evidence tending to show that defendant's post-traumatic stress disorder had its origins in the impoverished and violent circumstances surrounding his childhood provide ample support for an inference that the conditions that tend to suggest the appropriateness of submitting the (f)(6) statutory mitigating circumstance existed and *33affected defendant's ability to appreciate the criminality of his conduct or to conform his conduct to the requirements of the law at the time that he killed his estranged wife. As a result, given that "any reasonable doubt regarding the submission of a statutory or requested mitigating factor [must] be resolved in favor of the defendant," Phillips , 365 N.C. at 146, 711 S.E.2d at 152 (alteration in original) (quoting State v. Brown , 315 N.C. at 62, 337 S.E.2d at 825 ), and given that this Court has never required that the record contain explicit expert or lay testimony couched in the language set out in N.C.G.S. § 15A-2000(f)(6) as a precondition for the submission of the (f)(6) statutory mitigating circumstance to the jury, we conclude that the trial court erred by failing to submit the (f)(6) statutory mitigating circumstance to the jury at defendant's capital sentencing hearing. **327Finally, we are unable to hold that the trial court's failure to instruct the jury concerning the statutory mitigating circumstance enumerated in N.C.G.S. § 15A-2000(f)(6) was harmless beyond a reasonable doubt. The State's argument to the contrary notwithstanding, this Court has held that an erroneous failure to submit a statutory mitigating circumstance to the jury at a capital sentencing hearing is not cured by the submission of other statutory and non-statutory mitigating circumstances given that "[e]ach mitigating circumstance is a discrete circumstance" with "its own meaning and effect." Greene , 329 N.C. at 776, 408 S.E.2d at 187. For that reason, the submission of other statutory and non-statutory mitigating circumstances and the catch-all mitigating circumstance enumerated in N.C.G.S. § 15A-2000(f)(9) did not provide the jury with an adequate opportunity to consider the extensive evidence tending to show that defendant's "capacity ... to appreciate the criminality of his conduct or to conform his conduct to the requirements of law was impaired." In addition, given the nature and extent of the evidence contained in the present record concerning defendant's intellectual limitations, mental health diagnoses, and emotional turmoil, we are unable to conclude beyond a reasonable doubt that no juror would have found the existence of the (f)(6) statutory mitigating circumstance and given it substantial weight in the jury's ultimate decision had the (f) )(6) statutory mitigating circumstance been submitted to the jury at defendant's capital sentencing hearing. As a result, defendant is entitled to a new capital sentencing hearing.6
III. Conclusion
Thus, for the reasons set out above, we hold that the guilt-innocence and intellectual disability proceedings conducted before the trial court were free from error and that the outcomes reached in those proceedings should remain undisturbed. We further conclude, however, that the trial court committed prejudicial error by failing to submit the statutory mitigating circumstance enumerated in N.C.G.S. § 15A-2000(f)(6) to the jury at defendant's capital sentencing hearing. As a result, defendant's death sentence is vacated and this case is remanded to the Superior Court, Forsyth County for a new capital sentencing hearing.
NO ERROR IN GUILT-INNOCENCE PROCEEDING; DEATH SENTENCE VACATED; REMANDED FOR NEW CAPITAL SENTENCING PROCEEDING.