[1] Defendant argues that the trial court erred in denying his motion to suppress the evidence obtained from the warrantless seizure of his automobile. Absent consent, or some form of exigent circumstances, a warrant based on probable cause is required for a valid search and/or seizure under the Fourth Amendment. United States Constitution, Fourth Amendment. The United States Supreme Court in Coolidge v. New Hampshire, 403 U.S. 443 (1971), held that no exigent circumstances justified the failure of the police to obtain a warrant for the seizure and search of an automobile parked in the defendant’s driveway, because the police knew the car was there and planned to seize it when they went to defendant’s house.
A plurality of the Court fashioned a three-part test to determine if a search and/or seizure comes within the “plain view” doctrine established by this case. First, the initial intrusion that brings the evidence into plain view must be lawful. Second, the discovery of the evidence must be inadvertent. Third, it must be immediately apparent to the police that the items observed constitute evidence of a crime or are otherwise subject to seizure. Id. Our Supreme Court adopted this three-part analysis of war-rantless seizures or searches. See State v. Williams, 315 N.C. 310, 338 S.E. 2d 75 (1986).
*644In the case sub judice, as in Coolidge, defendant was in custody when his car was seized without a warrant. The police had probable cause, but they had no warrant. There were no exigent circumstances, the car did not come within the “plain view” exception, and thus the seizure was a violation of defendant’s Fourth Amendment rights.
While the trial court committed error in denying defendant’s motion to suppress the evidence obtained from the search of the car, the error in this case is harmless. Even error contravening one’s constitutional rights can be harmless. Chapman v. California, 386 U.S. 18 (1967); N.C.G.S. § 15A-1443(b); State v. Brown, 306 N.C. 151, 293 S.E. 2d 569, cert. denied, 459 U.S. 1080 (1982), and cert. denied, 479 U.S. 940 (1986).
The United States Supreme Court has applied the harmless error analysis to guilty pleas based on ineffective assistance of counsel. See Hill v. Lockhart, 474 U.S. 52 (1985). For a defendant to show that ineffective counsel was harmful, he must show that there is a reasonable probability that, but for counsel’s error, he would not have entered a plea of guilty. Id. at 58.
Error committed at trial infringing upon one’s constitutional rights is presumed to be prejudicial and entitles him to a new trial unless the error was harmless beyond a reasonable doubt. N.C.G.S. § 15A-1443(b); Brown, 306 N.C. 151, 293 S.E. 2d 569 (1982). This harmless error analysis has been applied to violations of the Fourth Amendment, and we see no reason why the analysis should not be applicable to guilty pleas partly based on evidence that should have been suppressed. See State v. Autry, 321 N.C. 392, 364 S.E. 2d 341 (1988).
In no way does this decision set precedent for denial of a motion to suppress to be considered harmless error because defendant, pursuant to G.S. 15A-979(b), pled guilty. It is because there is a full evidentiary record before us that gives this Court full benefit of all the evidence, admissible and inadmissible, that we are able to say, beyond all reasonable doubt, that failure to suppress evidence obtained from the car could not have affected defendant’s decision to plead guilty in light of the overwhelming evidence of his guilt.
*645The evidence presented at voir dire which showed that defendant was guilty of the crimes charged was overwhelming. Defendant admitted in his initial meeting with the police that he had been wearing a Dracula costume the night before. He was seen in the same Fast Fare earlier in the evening wearing that costume. The victim recognized defendant as a regular customer and was able to give a detailed description of him the night of the rape. The victim positively and unwaveringly identified the defendant both in a pre-trial photographic showing, and at the voir dire hearing.
The evidence found in defendant’s room was much more incriminating than that found in the car. The money found in the room was traced back to the Fast Fare, whereas the roll of nickels found in the car was not. The Dracula teeth found in the car only corroborated what defendant admitted early on. Lastly, and most importantly, as the State argues, defendant confessed to the crimes.
[2] Defendant further argues that because of his diminished mental capacity, he was unable to confess voluntarily and waive his Fifth Amendment rights. Standing alone, subnormal mental capacity does not render a confession incompetent, if it is in all other respects voluntarily and understandingly made. State v. Thompson, 287 N.C. 303, 214 S.E. 2d 742 (1975). In Thompson, the Supreme Court stated further:
If a person has the mental capacity to testify and to understand the meaning and effect of statements made by him, he possesses sufficient mentality to make a confession. Nevertheless, his mental capacity, or his lack of it, is an important factor to be considered in determining the voluntariness of a confession.
Id. at 318, 214 S.E. 2d at 752 (1975) (citing Blackburn v. Alabama, 361 U.S. 199 (1960)).
The trial judge here made findings that defendant had been diagnosed as mildly retarded. He noted, however, that such diagnosis was not a part of the evaluation of defendant made by Dorothea Dix State Hospital.
Defendant may have had a low mental IQ, however, he was not so diminished as to make his confession involuntary. See *646 Thompson, 287 N.C. 303, 214 S.E. 2d 742 (1975). The trial court, therefore, did not commit error in finding that defendant confessed voluntarily.
[3] Defendant next assigns as error the finding by the trial court that there was valid third party consent to search defendant’s residence.
N.C.G.S. § 15A-222Í3) states that, “[T]he consent needed to justify a search and seizure . . . must be . . .: By a person who by ownership or otherwise is reasonably apparently entitled to give or withhold consent to a search of premises.” This issue of common authority was addressed by the United States Supreme Court in U.S. v. Matlock, 415 U.S. 164 (1974), stating:
Common authority is, of course, not to be implied from the mere property interest a third party has in the property. The authority which justifies the third-party consent does not rest upon the law of property, with its attendant historical and legal refinements, . . . but rests rather on mutual use of the property by persons generally having joint access or control for most purposes, so that it is reasonable to recognize that any of the co-inhabitants has the right to permit the inspection in his own right and that the others have assumed the risk that one of their number might permit the common area to be searched.
This Court has held that N.C.G.S. § 15A-222(3) is “consistent with the language in Matlock . . . that permission may be ‘obtained from a third party who possessed common authority or other sufficient relationship to the premises or effects sought to be inspected.’ ” State v. Washington, 86 N.C. App. 235, 246, 357 S.E. 2d 419, 427 (1987), cert. denied, 322 N.C. 485, 370 S.E. 2d 235 (1988) (quoting State v. Kellum, 48 N.C. App. 391, 397, 269 S.E. 2d 197, 200; Matlock, 415 U.S. at 171) (emphasis deleted).
Findings of fact by the trial court show that defendant’s mother, who owned the residence and lived there with him, gave the police permission to search the residence, including defendant’s bedroom. When asked if defendant was paying rent, she replied “No,” but she also said defendant was “paying his way.” From these and other findings, the trial court concluded that de*647fendant’s mother had common authority over the premises with her son, that she owned the residence, and that she was apparently entitled to give or withhold consent to the search of the premises.
The trial court’s findings of fact were supported by competent evidence. There may have been evidence to the contrary, but it is the responsibility of the trial court to determine what evidence will be fact.
[4] Defendant next assigns as error the trial court’s denial of his motion to suppress the out-of-court photographic identification and subsequent in-court identification of the defendant by the victim.
Assuming arguendo that if the pre-hearing photographic identification by the victim was suggestive, and we do not believe that it was, it was nevertheless reliable under the totality of circumstances. See Matter of Stallings, 318 N.C. 565, 350 S.E. 2d 327 (1986), reh’g dismissed, 319 N.C. 669, 356 S.E. 2d 339 (1987); Neil v. Biggers, 409 U.S. 188 (1972); see, also, Manson v. Brathwaite, 432 U.S. 98 (1977).
We likewise conclude that even if the pre-hearing identification were unduly suggestive, the victim’s in-court identification was free from taint. See State v. Yancey, 291 N.C. 656, 231 S.E. 2d 637 (1977). The victim was with defendant for several hours and had ample time to view her assailant. Moreover, her identification of him in court was unwavering.
Defendant next assigns as error the trial court’s alleged refusal to allow defense counsel to cross-examine Detective Smith regarding defendant’s emotional state at the time of his confession and regarding the circumstances of the removal of defendant from his home. This is a feckless argument.
Defendant particularly claims that defense counsel was denied cross-examination of Detective Smith about whether he and the other officers had their guns unholstered when they went to defendant’s residence. The trial court did deny this cross-examination initially; however, any possible error was corrected when defense counsel was allowed to fully question the Detective about his and the other officers’ weapons.
*648Defendant further contends that defense counsel was prohibited from effectively cross-examining the Detective about his motives in requesting defendant to accompany the police to the station. Detective Smith admitted that he preferred to have defendant at the station for the questioning. Defense counsel continued in this line of questioning, after the detective’s acknowledgment of his motives, and the trial court correctly stemmed the redundant questions. See State v. Boykin, 298 N.C. 687, 259 S.E. 2d 883 (1979), cert. denied, 446 U.S. 911 (1980) (ruling on allowance of questioning by counsel is within discretionary power of trial court). There was no abuse of discretion by the trial court here. See id.
Even if defense counsel had been denied effective cross-examination of Detective Smith about his motives, “any subjective intent the officers may have had to arrest defendant is immaterial because their subjective intent is irrelevant to the question of whether a reasonable person in the defendant’s position would believe himself to be in custody.” State v. Braswell, 312 N.C. 553, 557, 324 S.E. 2d 241, 245 (1985).
[5] Defendant next contends that the trial court erred by refusing to allow defense counsel to cross-examine the victim’s doctor regarding the medical records and condition of the victim when she identified defendant’s picture. Defendant also argues that the court erred by not granting a motion to continue the voir dire in order that victim’s medical records could be obtained with which more fully to cross-examine the doctor.
From the record defendant clearly had ample time and opportunity to prepare his case. The medical records in question were known from the very beginning, however, defendant only subpoenaed them the day of the voir dire hearing to suppress the witness’s identification. A trial judge is fully justified in his discretionary denial of a last-minute continuance when it should have been made before extensive preparation for trial had been completed and the voir dire hearing begun. See State v. Baldwin, 276 N.C. 690, 174 S.E. 2d 526 (1970).
Defendant sought the medical records, and a continuance to obtain the records, in order to cross-examine defendant’s doctor, and to show that victim’s physical condition, or medications administered, diminished her perceptual abilities when she iden*649tified defendant’s photograph. Although without the medical records sought, the doctor could not relate what medications the victim had been given at any one time, he could and did testify as to her condition during her hospital stay.
The doctor did have before him some medical records, and these, coupled with his knowledge of his treatment procedure, enabled the doctor to testify sufficiently for the court to conclude the victim was alert and perceptive enough to identify the defendant.
Even assuming that the pre-hearing identification was unnecessarily suggestive, or that the victim was not alert, her in-court identification was clear and convincing and was made independent of any impermissible identification procedure. See Yancey, 291 N.C. 656, 231 S.E. 2d 637 (1977); see, also, State v. Stepney, 280 N.C. 306, 185 S.E. 2d 844 (1972).
[6] Defendant next assigns as error the trial court’s refusal to find a statutory mitigating factor under N.C.G.S. § 15A-1340.4(a)(2)(m) and that is that defendant had a good reputation in the community.
The test for determining when a trial court must find a statutory mitigating factor is two-pronged. First, the evidence must so clearly establish the fact in issue that no reasonable inferences to the contrary can be drawn. Secondly, the credibility of the evidence must be manifest as a matter of law. State v. Jones, 309 N.C. 214, 306 S.E. 2d 451 (1983). Further, uncontradicted, quantitatively substantial, and credible evidence may simply fail to establish, by a preponderance of the evidence, any factor in aggravation or mitigation. State v. Michael, 311 N.C. 214, 316 S.E. 2d 276 (1984).
Whether factors are mitigating or aggravating, they still must be proven by a preponderance of the evidence. Id. Defendant’s only evidence as to his good reputation in the community was the testimony of his mother. Defendant had been away from the community for ten years and had returned only two or three months prior to the crime.
Although a witness related to a defendant is not necessarily incredible, the trial court has the discretion to reject testimony of biased witnesses. See State v. Taylor, 309 N.C. 570, 308 S.E. 2d *650302 (1983); see, also, State v. Benbow, 309 N.C. 538, 308 S.E. 2d 647 (1983). The trial court did not err in declining to find, as a statutory mitigating factor, defendant’s good reputation in the community.
[7] Finally, defendant assigns as error the trial court’s refusal to review, in camera, defendant’s parole records during both the suppression and sentencing hearings.
N.C.G.S. § 15-207 states that;
All information and data obtained in the discharge of official duty by any probation officer shall be privileged information, shall not be receivable as evidence in any court, and shall not be disclosed directly or indirectly to any other than the judge or to others entitled under this Article to receive reports, unless and until otherwise ordered by a judge of the court or the Secretary of Correction.
Defendant requested, in a motion for discovery, any “psychological or psychiatric records, files, information or knowledge in the possession of the State or any of its agents, including the Department of Corrections, Division of Prisons, Pre-Release & Aftercare or Parole Officer James Bellamy or Investigators Van Smith or Barbara Wolfe. . . .”
The trial court stated in the suppression hearing 'that N.C.G.S. § 15-207 requires a court order to obtain probation records to protect their confidentiality, and that this applied to defendant. The court stated further that if defense counsel would follow the procedure under this statute, he might be allowed access to defendant’s file.
The material in defendant’s probation records was not in the possession of the State’s attorney, and the only way it could be obtained was through N.C.G.S. § 15-207. Defendant’s discovery motion, therefore, was not applicable to defendant’s probation records in question.
We conclude that the trial court did not err in refusing to grant defendant privileged information, regardless of the fact that it pertained to defendant. Had defense counsel followed the statutory procedure under N.C.G.S. § 15-207, he possibly could *651have gained access; as it was, he was no more entitled than the State or anyone else to those confidential records.
[8] Finally, there was no error in the trial court’s denial of defendant’s motion to suppress the statements he made to the law enforcement officers. In short, a reasonable person in defendant’s circumstances would not have felt himself in custody. The court found that defendant was not in custody, and that defendant’s statements were voluntarily made. Findings of fact supported as they are here by the record are binding on this Court. State v. Stevens, 305 N.C. 712, 291 S.E. 2d 585 (1982).
“Voluntariness” with which we are concerned in a case like this is the freedom from compelling influences that force a person to say what he otherwise would not say. See Rhode Island v. Innis, 446 U.S. 291 (1980). That type of compelling influence simply was not present in this case.
We find no error in the trial court’s rulings at defendant’s suppression hearings.
Affirmed.
Chief Judge Hedrick and Judge ORR concur.