[1] Defendant first assigns as error the action of the trial judge in permitting the district attorney to reexamine and challenge for cause Mrs. Brady, a prospective juror, and to reexamine and challenge peremptorily Mr. Crisp, another prospective juror, after both had been passed by the district attorney and counsel for defendant.
Before the State passed Mrs. Brady, she stated she had not formed an opinion as to defendant’s guilt or innocence. However, before the jury was finally selected and impaneled, the trial court was informed that Mrs. Brady had formed an opinion as to defendant’s sanity. On further examination, Mrs. Brady stated she now believed defendant was insane at the time of the homicide and was not guilty of the crime charged by reason of insanity. Over objection, this juror was excused by the State for cause.
Before the State passed Mr. Crisp, he indicated he only knew defendant casually. Before the jury was impaneled, the court was informed that Mr. Crisp was a good friend of defend-ánt and his family. Upon reexamination, this juror admitted *350that defendant visited his son at their home two or three times each week, that defendant and his son were the best of friends, and that he knew defendant quite well. The State, over objection, then excused Mr. Crisp peremptorily.
In State v. Westbrook, 279 N.C. 18, 181 S.E. 2d 572 (1971), defendant was on trial for murder. The trial judge excused a juror on the grounds of family hardship. The circumstances constituting the hardship came to the trial judge’s attention after the juror had been accepted by both the State and the defendant and had been sworn but not impaneled. We held that the trial judge’s action did not constitute error.
In State v. Harris, 283 N.C. 46, 194 S.E. 2d 796 (1973), defendant assigned as error the action of the trial judge in permitting the solicitor to reexamine and successfully challenge for cause a prospective juror who had been passed by the State and tendered to defendant. Before the State passed and tendered this juror, she indicated her willingness to vote for a verdict which would result in the death penalty. Prior to jury impanelment, however, she let it be known that she had changed her opinion about capital punishment. The trial judge thereupon allowed the solicitor to reexamine the prospective juror. The reexamination revealed that she had talked with her pastor during the overnight recess and as a result of that conversation she would not, under any circumstances, vote for a verdict which would impose the death sentence. Over objection, the trial judge allowed the solicitor to successfully challenge her for cause. We approved stating:
“The competency of jurors is a matter to be decided by the trial judge. Decisions as to a juror’s competency at the time of selection and their continued competency to serve are matters resting in the trial judge’s sound discretion. G.S. 9-14; State v. Johnson, 280 N.C. 281, 185 S.E. 2d 698. The trial judge’s ruling on such questions are [sic] not subject to review on appeal unless accompanied by some imputed error of law. State v. Watson, 281 N.C. 221, 188 S.E. 2d 289.”
See also State v. Atkinson, 275 N.C. 288, 167 S.E. 2d 241 (1969) ; State v. Spence, 271 N.C. 23, 155 S.E. 2d 802 (1967).
The solicitor did not attempt to challenge Mr. Crisp for cause, but challenged him peremptorily. Peremptory challenges are challenges that may be made according to the judgment *351of the party entitled thereto without being required to assign the reason therefor, and the reason for challenging a juror peremptorily cannot be inquired into. State v. Noell, 284 N.C. 670, 202 S.E. 2d 750 (1974) ; State v. Allred, 275 N.C. 554, 169 S.E. 2d 833 (1969).
The court did not abuse its discretion in allowing the district attorney to reexamine these prospective jurors and in excusing one for cause and the other peremptorily. This assignment is overruled.
Defendant’s second assignment of error is directed to the court’s refusal to disqualify the witness Mrs. Dorothy Wetmore. Defendant contends that this witness was not mentally competent to testify in that her testimony showed that her thought process was extremely confused and that she was motivated by delusional thinking that her husband was out to get her. Dr. Robert L. Rollins, a qualified psychiatrist and head of the Forensic Unit at Dorothea Dix Hospital, testified that she was suffering from a mental illness known as chronic paranoid schizophrenia.
Defendant did not object to Mrs. Wetmore’s competency as a witness or to her testimony during the trial, but after verdict and after sentence had been pronounced, he moved for a new trial for the reason that Mrs. Wetmore was mentally incompetent. Defendant contends that the trial judge abused his discretion in allowing Mrs. Wetmore’s testimony to stand after he heard her and Dr. Rollins testify.
In State v. Benton, 276 N.C. 641, 174 S.E. 2d 793 (1970), defendant contended that the court erred in allowing one Epley to testify after a psychiatrist testified that in his opinion it was impossible for Epley to give reliable testimony. In overruling this contention, Justice Sharp, now Chief Justice, speaking for the Court said:
“ . . . The law does not say that the decision of the trial judge as to the competency of a witness shall be controlled by expert medical testimony or that the evidence of a psychiatrist, whether employed by the State or defendant, or appointed by the Court, is entitled to greater weight than that of a qualified lay witness. ...” Id. at 650, 174 S.E. 2d at 799.
*352In State v. Robinson, 283 N.C. 71, 194 S.E. 2d 811 (1973), the defendant contended that the court erred in failing to find that the State’s witness Tinsley lacked sufficient mental capacity to be permitted to testify. We held that there was no merit in this contention, quoting with approval from State v. Benton, supra, as follows:
“ ‘Unsoundness of mind does not per se render a witness incompetent, the general rule being that a lunatic or weak-minded person is admissible as a witness if he has sufficient understanding to apprehend the obligation of an oath and is capable of giving a correct account of the matters which he has seen or heard with respect to the questions at issue. The decision as to the competency of such a person to testify rests largely within the discretion of the trial court.’ Accord: State v. Squires, 265 N.C. 388, 144 S.E. 2d 49; State v. Cade, 215 N.C. 393, 2 S.E. 2d 7; Stansbury, North Carolina Evidence, 2d Ed., § 55; 97 C.J.S., Witnesses, § 57(b).”
And, “ . . . [i]t is the consensus that mental eccentricities or aberrations which fall short of complete mental incapacity do not render a witness incompetent, although they may affect his credibility.” 3 Jones on Evidence § 20:13, pp. 614-15 (6th ed. 1972).
In State v. Merrick, 172 N.C. 870, 90 S.E. 257 (1916), as in the present case, defendant did not object to the testimony of a witness but at the conclusion of the testimony moved to strike. There we stated: “ . . . An objection to testimony not taken in apt time is waived. [Citations omitted.] When testimony has thus been admitted without objection, the granting or denying a motion to strike out rests in the discretion of the court. [Citations omitted.] . ”
[2] We have held many times that the competency of a witness to testify is to be determined at the time the witness is called to testify and rests mainly, if not entirely, in the sound discretion of the trial judge in the light of his examination and observation of the particular witness. 7 Strong, N. C. Index 2d, Witnesses § 1 (1968) ; State v. Cooke, 278 N.C. 288, 179 S.E. 2d 365 (1971) ; State v. Bowden, 272 N.C. 481, 158 S.E. 2d 493 (1968) ; State v. Turner, 268 N.C. 225, 150 S.E. 2d 406 (1966) ; Artesani v. Gritton, 252 N.C. 463, 113 S.E. 2d 895 (1960) ; State v. Merritt, 236 N.C. 363, 72 S.E. 2d 754 (1952).
*353 [3] Defendant waited too late to challenge the competency of Mrs. Wetmore, but assuming that his objections to her competency were timely made, we hold that defendant’s motion was properly denied. Mrs. Wetmore’s trial testimony, although long and rambling at times, was clear and consistent on all material matters and was fully corroborated by defendant, the local police, and S.B.I. agents. The trial judge had a firsthand opportunity to observe her demeanor, sincerity, perception and memory. There is nothing in the record to indicate that the trial judge abused his discretion in failing to grant defendant a new trial because of Mrs. Wetmore’s incompetency to testify.
[4] Defendant next assigns as error that portion of the charge in which the trial court instructed the jury that if the State proved beyond a reasonable doubt that the defendant intentionally killed the deceased with a deadly weapon then “the law raises two presumptions: first, that the killing was unlawful, and second, that it was done with malice.”
Defendant’s counsel, with commendable candor, states in his brief:
“Defendant is aware that the instructions complained of here are consistent with the case law of this state. Malice and unlawfulness of the. killing are presumed, when a deadly weapon is intentionally used; 4 Strong Index, 2d Homicide, Sec. 14, pp. 207-209. The burden is upon the defendant to disprove malice and reduce a killing to voluntary manslaughter. State v. Absher, 226 N.C. 656, 40 S.E. 2d 26 (1946). Your defendant contends these rules are no longer valid in this society ....
❖ * *
“ . . . The defendant is aware that this Court recently rejected this same argument in the case of State v. Sparks, 285 N.C. 631 (1974).”
Defendant is correct. We did reject this argument in Sparks, and we adhere to that decision. We need only repeat what we said in Sparks, supra, at 644, 207 S.E. 2d at 719:
“ ... We have carefully considered defendant’s argument that we should change our well-established rule. However, we are not persuaded to do so. See State v. Jennings, [276 N.C. 157, 171 S.E. 2d 447 (1970)]; State v. Propst [274 N.C. 62, 161 S.E. 2d 560 (1968)].”
*354This assignment is overruled.
[5] The trial court also charged:
“The defendant has the burden of proving he was insane. However, unlike the State which must prove the defendant’s guilt beyond a reasonable doubt, the defendant need only prove his insanity to your satisfaction.
“Therefore, I charge that if you are satisfied from the evidence that the defendant, at the time of the alleged crime, and as the result of mental disease or defect, either did not know the nature and quality of his act, or did not know that it.was wrong, he would be not guilty.
“If you find the defendant not guilty for this reason, but otherwise would have found him guilty, you must find him not guilty by reason of insanity.”
Defendant contends that the foregoing instructions in effect limited the jury’s permissible not guilty verdict to only a verdict of “not guilty by reason of insanity” and foreclosed the possibility of a verdict of “not guilty” by virtue of possible failings in the State’s case. This contention is without merit. On several occasions the trial judge instructed the jury that it might return either of five permissible verdicts and at one time told them that throughout their deliberations they would have a written list designating those verdicts. He clearly stated:
“Under this charge and the evidence in this case, there are five possible verdicts that you can arrive at. First is guilty of First Degree Murder, second is guilty of Second Degree Murder, third is guilty of Voluntary Manslaughter, the fourth is not guilty, and the fifth is not guilty by reason of insanity.
“And it has been agreed, members of the jury, by counsel for the State and for the defendant that I might submit to you, when you go to your room, a list of the possible verdicts which you can use in your deliberations and in returning your verdict in open Court. Your verdict would be a verbal or oral verdict, but you could use this list as it has been agreed.” (Emphasis added.)
Again, immediately before that portion of the charge to which defendant objected, the trial judge carefully recited the substantive elements required to be found by the jury before *355it could return a verdict of guilty of either first degree murder, second degree murder or manslaughter, and then said: “However, if you do not so find or have a reasonable doubt as to one or more of these things, you will return as your verdict a verdict of not guilty.” Following this, the judge charged upon the effect to be given defendant’s allegations of mental impairment and then stated: “If you find the defendant not guilty for this reason, but otherwise would have found him guilty, you must find him not guilty by reason of insanity.”
Immediately before the jury retired to deliberate, the judge again charged that it might return verdicts of not guilty on all of the offenses charged or not guilty by reason of insanity. This instruction was repeated when the jury returned and asked for additional instructions. “ . . . The charge of the court must be read as a whole. State v. Wilson, 176 N.C. 751, 97 S.E. 496 (1918). A disconnected portion may not be detached from the context of the charge and then critically examined for an interpretation from which erroneous expressions may be inferred. State v. Gatling, 275 N.C. 625, 170 S.E. 2d 593 (1969) ; State v. McWilliams [277 N.C. 680, 178 S.E. 2d 476 (1971)] ; State v. Alexander, 279 N.C. 527, 184 S.E. 2d 274 (1971).” State v. Bailey, 280 N.C. 264, 185 S.E. 2d 683 (1972). See 3 Strong, N. C. Index 2d, Criminal Law § 168 (1967).
Construing the charge as a whole, we hold that the trial court properly protected the rights of defendant by instructing the jury to return a verdict of “not guilty” if possessed of any reasonable doubt as to the sufficiency of the State’s case, and further by instructing the jury to return a verdict of “not guilty by reason of insanity” if convinced, regardless of the sufficiency of the State’s case, that the defendant at the time of the alleged crime, and as the result of a mental disease or defect, did not know the nature and quality of his act or did not know that it was wrong.
Next, defendant assigns as error the court’s final mandate to the jury.
Defendant contends that this portion of the charge is conflicting on several material points. We have carefully examined the objected to portion of the charge and fail to detect any such conflict. The instruction complies with settled law in this State. State v. Woods, 278 N.C. 210, 179 S.E. 2d 358 (1971); State *356 v. Propst, supra,; State v. Gordon, 241 N.C. 356, 85 S.E. 2d 322 (1955). This assignment of error is overruled.
[6] Defendant further contends that the court should have instructed the jury as follows regarding his mental condition at the time of the killing:
“There is evidence which tends to show that the defendant was insane at the time of the acts alleged in this case. Insanity which precludes the mental process of premeditation and deliberation is a defense to the charge of murder in the first degree.
“Generally insanity is a complete defense to these charges. In order for this to be so the disease or defect must have so impaired the defendant’s mental capacity that he either did not know the nature and quality of his act or did not know that it was wrong.
“However, if you find that the defendant had a defect in his mental reasoning you should consider whether this condition affected his ability to formulate the specific intent which is required for conviction of first degree murder. In order for you to find the defendant guilty of first degree murder you must find, beyond a reasonable doubt, that the defendant had the specific intent to kill or to premeditate or to deliberate the killing of Edwin H. Wetmore. If as a result of mental defect of reasoning the defendant did not have the required specific intent, you must find the defendant not guilty of first degree murder.”
Several states have adopted a so-called theory of diminished responsibility with respect to specific intent of crimes such as first degree murder, and hold that a defendant may offer evidence of an abnormal mental condition, which, although not sufficient in degree to establish legal insanity, tends to show that he did not have the capacity to deliberate or premeditate at the time the homicide was committed — elements necessary for a conviction of murder in the first degree. Defendant’s counsel in his brief admits that North Carolina has not adopted this theory. For a list of cases from other jurisdictions supporting the theory of diminished responsibility, see State v. Baldwin, 276 N.C. 690, 174 S.E. 2d 526 (1970). See also Annot., 22 A.L.R. 3d 1228.
Our Court has consistently said that the test of insanity as a defense to a criminal charge is the capacity to distinguish *357between right and wrong at the time of and in respect to the matter under investigation. State v. Cooper, 286 N.C. 549, 213 S.E. 2d 305 (1975); State v. Humphrey, 283 N.C. 570, 196 S.E. 2d 516 (1973) ; State v. Benton, supra; State v. Rogers, 275 N.C. 411, 168 S.E. 2d 345 (1969), cert. den. 396 U.S. 1024, 24 L.Ed. 2d 518, 90 S.Ct. 599 (1970). We addressed the exact question before us very recently in State v. Cooper, supra, a case very similar on its facts to the present case. The question was carefully examined by Justice Lake writing for the Court. Suffice to say that nothing has transpired in the short period since we decided Cooper to incline us to modify our view as there set out.
[7] We have also rejected the irresistible impulse doctrine which defendant here seeks to invoke.
As stated by Justice Branch in State v. Humphrey, supra, at 574, 196 S.E. 2d at 519 :
“Defendant’s counsel ably presented arguments for adoption of the ‘irresistible impulse doctrine.’ However, neither defendant’s arguments nor our research disclose reasons sufficiently persuasive to warrant modification or abrogation of the long recognized ‘right and wrong’ test of criminal responsibility.”
This assignment is overruled.
[8] Finally, defendant contends that the entry of a judgment ordering the death penalty violates the constitutional guarantee against cruel and unusual punishment and that the arbitrariness of the imposition of the death penalty deprives him of equal protection of the law guaranteed by the Constitution. Defendant admits that this Court has rejected this argument in State v. Jarrette, 284 N.C. 625, 202 S.E. 2d 721 (1974). We adhere to our decision in that case. Further discussion would serve no useful purpose. See State v. Fowler, 285 N.C. 90, 203 S.E. 2d 803 (1974) ; State v. Dillard, 285 N.C. 72, 203 S.E. 2d 6 (1974) ; State v. Crowder, 285 N.C. 42, 203 S.E. 2d 38 (1974) ; State v. Waddell, 282 N.C. 431, 194 S.E. 2d 19 (1973).
The record in this case discloses a vicious, brutal, senseless murder of a father by a son. The evidence is such that the jury could have found that defendant was not guilty by reason of insanity or, as it did, that defendant, because of hatred for his *358father, unlawfully with malice, premeditation and deliberation, killed him. It was for the jury to decide.
Because of the imposition of the death sentence, we have carefully examined the entire record in this case and have considered every contention and argument advanced by defendant. Our examination discloses that defendant received a fair trial, free from prejudicial error.
No error.