Defendant’s first thirty-nine exceptions and assignments of error based thereon are addressed to the admission of evidence. Those which merit discussion will be considered in numerical order.
 Defendant initially asserts that the trial court erred in allowing the witness Donald Brake to testify that when defendant, at the Hamburger Shop shortly after the fight, told him he had kicked Jimmie Collie so hard he had sprained his ankle, he “seemed to be joking about it.” Defendant claims the witness was thus permitted to state a conclusion which was irrelevant and highly prejudicial in that it indicated an attitude of unconcern on defendant’s part. No authority is cited and no reason stated in support of this assignment save the bare assertion that it was irrelevant and prejudicial. For that reason the assignment is deemed abandoned under Rule 28, Rules of Practice in the Supreme Court, 254 N.C. 783 at 810. Nevertheless, admission of the evidence was not error. The statement attributed to defendant was highly relevant and material, and defendant’s jocular mode of expression was admissible as a shorthand statement of fact. State v. Goines, 273 N.C. 509, 160 S.E. 2d 469 (1968); State v. Gray, 180 N.C. 697, 104 S.E. 647 (1920); Stansbury, N. C. Evidence (2d Ed., 1963) § 125. This assignment has no merit.
[2, 3] Assignments of Error 2 through 8 relate to the introduction of photographs of the deceased to illustrate the testimony of various witnesses. Viewed in context and in the setting at the trial, it appears that in each instance the familiarity of the testifying witness with deceased was established, and the accuracy of the photograph as a true likeness of Jimmie Collie *358was shown. They were offered and admitted over defendant’s general objection. When a general objection is interposed and overruled, it will not be considered reversible error if the evidence is competent for any purpose. Rule 21, Rules of Practice in the Supreme Court, 254 N.C. 783 at 803; State v. Ham, 224 N.C. 128, 29 S.E. 2d 449 (1944). Even so, the trial judge invariably instructed the jury to consider each photograph for illustrative purposes only and not as substantive evidence. They were competent for the limited purpose stated and their admission was not error. State v. Casper, 256 N.C. 99, 122 S.E. 2d 805 (1961), cert. den., 376 U.S. 927, 11 L. Ed. 2d 622, 84 S.Ct. 691 (1964).
Defendant insists, however, that the State sought to use the photographs to establish the corpus delicti; that photographs may not be used for that purpose, and therefore the corpus delicti was never shown by competent evidence.
 “The phrase ‘corpus delicti’ means literally the body of the transgression charged, the essence of the crime or offense committed. To establish the corpus delicti it is necessary to show the commission of a particular act and its commission by unlawful means.” 1 Wharton’s Criminal Law and Procedure (Anderson Ed., 1957), § 66. Strong and cogent circumstantial evidence may be sufficient to prove the corpus delicti where no direct evidence is available. “The corpus delicti, in cases such as we are considering, is made up of two things: first, certain facts forming its basis, and, secondly, the existence of criminal agency as the cause of them.” State v. Williams, 52 N.C. 446, 78 Am. Dec. 248 (1860). See also State v. Jones, 249 N.C. 134, 105 S.E. 2d 513 (1958); State v. Cope, 240 N.C. 244, 81 S.E. 2d 773 (1954); State v. Cuthrell, 233 N.C. 274, 63 S.E. 2d 549 (1951). In homicide cases the requirements sufficient to establish the corpus delicti are more specific: (1) There must be a corpse, or circumstantial evidence so strong and cogent that there can be no doubt of the death, State v. Williams, supra; and (2) the criminal agency must be shown. State v. Minton, 234 N.C. 716, 68 S.E. 2d 844, 31 A.L.R. 2d 682 (1952). “The independent evidence must tend to point to some reason for the loss of life other than natural causes, suicide or accident.” Rollin M. Perkins, The Corpus Delicti of Murder, 48 Va. L. Rev. 173 (1962).
*359  Here, defendant argues that the State failed to show by competent evidence that the body upon which the autopsy was performed was the body of Jimmie Collie because the photograph exhibited to the doctor was not competent as substantive evidence and was therefore inadmissible for the purpose of proving corpus delicti. This contention is not supported by the decided cases.
Photographs have been held properly admitted, with appropriate limiting instructions, to illustrate testimony establishing the corpus delicti in North Carolina and other jurisdictions. State v. Gardner, 228 N.C. 567, 46 S.E. 2d 824 (1948); State v. Miller, 219 N.C. 514, 14 S.E. 2d 522 (1941); Hines v. State, 260 Ala. 668, 72 So. 2d 296 (1954); Potts v. People, 114 Colo. 253, 158 P. 2d 739, 159 A.L.R. 1410 (1945); State v. Myers, 7 N.J. 465, 81 A. 2d 710, 25 A.L.R. 2d 1171 (1951) ; Annotation, Admissibility of Photograph of Corpse in Prosecution for Homicide or Civil Action for Causing Death, 73 A.L.R. 2d 769 (1960) at § 14; 40 Am. Jur. 2d, Homicide, § 418.
This is in accord with the general rule that “photographs are competent to be used by a witness to explain or to illustrate anything it is competent for him to describe in words.” State v. Gardner, supra. The photographs must, of course, be properly limited and authenticated, and must be relevant. State v. Atkinson, 275 N.C. 288, 167 S.E. 2d 241 (1969).
 Applying these principles to the facts in this case, it appears that Dr. Haberyan, although not previously acquainted with Jimmie Collie, testified that the photograph exhibited to him was a fair and accurate representation of the body upon which he performed an autopsy, and expresed his expert opinion that a kick in the head inflicted by a leather shoe could have caused death. The witness Dennis Eason, who saw Jimmie Collie at the fight in Aycock Park, said he recognized the same photograph which had been shown to Dr. Haberyan as a fair likeness of Jimmie Collie on the night he was killed. The father of the deceased identified the same body as that of his son. Thus there was no failure to connect the subject of the autopsy to the deceased named in the bill of indictment. The assignments of error based on such contention are overruled.
 Manifestly, there was plenary evidence in proof of the second element of the corpus delicti. Several witnesses testified *360that Jimmie Collie was kicked in the head by defendant Dawson following which blood was seen running from the victim’s mouth, ears and nose. These witnesses observed that the victim had no pulse and was not breathing. Dr. Haberyan testified essentially that death was caused by a skull fracture behind the right ear and near the base of the brain, compressing vital centers controlling the heart and lungs, and that the fracture was caused by a blow inflicted by a blunt instrumentality such as a cement curbing or a leather shoe. There is no evidence in the record that when Jimmie Collie fell from the hood of the car the back of his head struck the curb. To the contrary, the testimony shows that he fell from the hood of the car and landed face down. This points to the conclusion that the blow which caused death was inflicted by Edward Dawson’s shoe and greatly weakens the suggestion that Collie’s death was attributable to other causes. It was a question for the jury. Defendant’s motion for nonsuit was properly denied.
Defendant’s Exceptions and Assignments of Error Nos. 9 and 13 through 39 concern the admission of testimony involving a fracas at the gymnasium of Benvenue School on the night of November 7, 1969, at a party given by the coach for his football players. These assignments therefore will be grouped for discussion.
 Defendant had testified that due to injuries received when he was thrown from a horse and when he was involved in an automobile accident on November 2, 1969, his physical condition was such that he was unable to kick Jimmie Collie as alleged by the State. On cross-examination the solicitor referred to defendant’s professed physical disability and asked: “Didn’t keep you from getting into a fight with the coach of the football team at Benvenue School, did it?” Defendant’s objection and motion to strike were overruled. Later, over the continued objections of defendant, the State was permitted to elicit rebuttal testimony from Coach Hendricks and his wife to the effect that Edward Dawson was neither a student nor a football player at Benvenue School; that defendant came to the party uninvited and was requested to leave; that he left but returned in a half hour accompanied by fifteen other boys who marched into the gym and assaulted the coach; that defendant pressed the arm cast he was wearing against Coach Hendricks’ neck, struck the coach, was strong and active and had no apparent disability save *361the cast on his arm. This evidence was offered and received for the sole purpose of showing the physical condition of the defendant at that time and to impeach defendant’s testimony that on the night of November 22 when Jimmie Collie was killed defendant was so disabled by injuries that he could not have struck or kicked anyone. The jury was specifically instructed to consider the evidence only for that purpose.
 The evidence was competent for the limited purpose for which it was admitted. Under the North Carolina rule of wide-open cross-examination, so called because the scope of inquiry is not confined to matters brought out on direct examination, questions designed to impeach the witness, if relevant to the controversy, may cover a wide range and are permissible within the discretion of the court. State v. Penley, 277 N.C. 704, 178 S.E. 2d 490 (1971); State v. Blackwell, 276 N.C. 714, 174 S.E. 2d 534 (1970); State v. Sheffield, 251 N.C. 309, 111 S.E. 2d 195 (1959); State v. Dickerson, 189 N.C. 327, 127 S.E. 256 (1925); Stansbury, N. C. Evidence (2d Ed., 1963), §§ 35, 56; 4 Jones on Evidence (5th Ed., 1958), §§ 928-929.
 Nor was the testimony of Coach Hendricks and his wife, offered by way of rebuttal to impeach defendant’s testimony of his professed physical incapacity, rendered inadmissible by the general rule which prohibits the State from offering evidence of other offenses committed by the defendant on trial. Such evidence, when it “tends to prove any other relevant fact . . . will not be excluded merely because it also shows him to have been guilty of an independent crime.” Stansbury, N. C. Evidence (2d Ed., 1963), § 91; State v. McClain, 240 N.C. 171, 81 S.E. 2d 364 (1954). Assignments of Error Nos. 9 and 13 through 39 are thus without merit and are overruled.
 Appellant next contends that the trial court erred in allowing Detective Hataway to testify in rebuttal that defendant stated during an in-custody interrogation that he kicked the deceased two or three times. The record reveals that upon timely objection a voir dire was conducted, at the conclusion of which the judge made findings of fact that before defendant made any statement to Officer Hataway he was fully advised of his constitutional rights and understood them. The judge concluded that any statement made by defendant to the officer was made knowingly, freely and voluntarily. Nevertheless, defendant now contends his incriminating statement was involuntary because his *362mother, who was present at the police station at the time of the interrogation, was not apprised of her son’s constitutional rights and was not allowed to be present at the interrogation. In support of this contention, defendant cites Miranda v. Arizona, 384 U.S. 436, 16 L. Ed. 2d 694, 86 S.Ct. 1602 (1966), and Escobedo v. Illinois, 378 U.S. 478, 12 L. Ed. 2d 977, 84 S.Ct. 1758 (1964).
We find nothing in Miranda or Escobedo which even remotely supports defendant’s position. A confession is not rendered involuntary merely because the person making it is a minor. State v. Murry, 277 N.C. 197, 176 S.E. 2d 738 (1970); State v. Hill, 276 N.C. 1, 170 S.E. 2d 885 (1969); Annotation, Voluntariness and Admissibility of Minor’s Confession, 87 A.L.R. 2d 624 (1963). The California Supreme Court in People v. Lara, 67 Cal. 2d 365, 62 Cal. Rptr. 586, 432 P. 2d 202 (1967), held that the “totality of circumstances” rule for the admission of out-of-court confessions applies to the confessions of minors as well as adults. The Court said: “We cannot accept the suggestion of certain commentators . . . that every minor is incompetent as a matter of law to waive his constitutional rights to remain silent and to an attorney unless the waiver is consented to by an attorney or by a parent or guardian who has himself been advised of the minor’s rights.” The Court then concluded: “This, then, is the general rule: a minor has the capacity to make a voluntary confession, even of capital offenses, without the presence or consent of counsel or other responsible adult, and the admissibility of such a confession depends not on his age alone but on a combination of that factor with such other circumstances as his intelligence, education, experience, and ability to comprehend the meaning and effect of his statement.” See also Vaughn v. State, 456 S.W. 2d 379 (Tenn. Crim. App., 1970); McLeod v. State, 229 So. 2d 557 (Miss., 1969); United States ex rel Walker v. Maroney, 313 F. Supp. 237 (1970); Commomoealth v. Darden, 441 Pa. 41, 271 A. 2d 257 (1970).
 So it is with us. The correct test of the admissibility of a confession is whether the confession was, in fact, voluntary under all the circumstances of the case. State v. Gray, 268 N.C. 69, 150 S.E. 2d 1 (1966). While the testimony on voir dire is conflicting, there is ample evidence to support the finding that defendant was apprised of his constitutional rights and knowingly and voluntarily made the statement attributed to him. Under *363our procedure such findings by the trial judge are conclusive if supported by competent evidence. State v. Wright, 274 N.C. 84, 161 S.E. 2d 581 (1968); State v. Gray, supra; State v. Barnes, 264 N.C. 517, 142 S.E. 2d 344 (1965); State v. Outing, 255 N.C. 468, 121 S.E. 2d 847 (1961).
We are aware of the different procedure used in the federal courts', where an independent examination of the facts is made to determine voluntariness. In earlier federal cases it was held that reviewing federal courts were likewise bound by the facts as found by the trial judge. See, e.g., Watts v. Indiana, 338 U.S. 49, 93 L. Ed. 1801, 69 S.Ct. 1347 (1949); Lyons v. Oklahoma, 322 U.S. 596, 88 L. Ed. 1481, 64 S.Ct. 1208 (1944); Lisenba v. California, 314 U.S. 219, 86 L. Ed. 166, 62 S.Ct. 280 (1941). In Watts, Justice Frankfurter wrote: “On review here of State convictions, all those matters which are usually termed issues of fact are for conclusive determination by the State courts and are not open for reconsideration by this Court.” He noted, however, the amorphous nature of a “constitutional fact.” More recently, the United States Supreme Court has greatly enlarged the scope of federal independent determination of facts with respect to constitutional rights. See Haynes v. Washington, 373 U.S. 503, 10 L. Ed. 2d 513, 83 S.Ct. 1336 (1963); Davis v. North Carolina, 384 U.S. 737, 16 L. Ed. 2d 895, 86 S.Ct. 1761 (1966); Clewis v. Texas, 386 U.S. 707, 18 L. Ed. 2d 423, 87 S.Ct. 1338 (1967). In Davis, the Court said: “It is our duty in this case, ... as in all of our prior cases dealing with the question whether a confession was involuntarily given, to examine the entire record and make an independent determination of the ultimate issue of voluntariness.” Professor Strong, who recently chronicled this change of scope, observes: “Clearly, ‘independent examination of the whole record’ means, where deemed necessary to vindication of the constitutional claim, review of facts disputed as well as undisputed.” Frank R. Strong, The Persistent Doctrine of “Constitutional Fact,” 46 N.C.L. Rev. 223 (1968). Moreover, United States District Courts have wide fact-finding powers exercisable in the determination of federal constitutional claims on habeas corpus. Townsend v. Sain, 372 U.S. 293, 9 L. Ed. 2d 770, 83 S.Ct. 745 (1963) ; Fay v. Noia, 372 U.S. 391, 9 L. Ed. 2d 837, 83 S.Ct. 822 (1963). See J. Skelly Wright and Abraham D. Sofaer, Federal Habeas Corpus for State Prisoners: The Allocation of Fact-Finding Responsibility, 75 Yale L. J. 895 (1966).
*364Our procedure upholding the findings if supported by competent evidence is grounded on the reliability of the trial judge who hears the testimony on voir dire, observes the demeanor of the witnesses, and sits in a more strategic position to judge credibility and determine the true facts with respect to volun-tariness. Here, the facts are only weakly disputed and the record strongly supports the findings. All assignments of error addressed to the admission of defendant’s statement are overruled.
It is worthy of note that under the law as recently declared by the United States Supreme Court defendant Dawson’s statement to the officers, even if obtained in violation of Miranda, would be competent on rebuttal (so used here) to impeach and attack the credibility of his trial testimony. In Harris v. New York, 39 U.S.L.W. 4281, decided February 24, 1971, the prosecution made no effort in its case in chief to use statements allegedly made by Harris, conceding that they were inadmissible under Miranda for that the required warnings of constitutional rights had not been given. Harris took the stand in his own defense and his testimony contrasted sharply with what he told the police shortly after his arrest. In rebuttal, the prosecution was permitted to use his inadmissible statements to the police for the limited purpose of impeaching and attacking the credibility of defendant’s trial testimony. The Supreme Court of the United States affirmed, saying: “It does not follow from Miranda that evidence inadmissible against an accused in the prosecution’s case in chief is barred for all purposes, provided of course that the trustworthiness of the evidence satisfies legal standards.”
 Finally, defendant assigns as error several portions of the charge. Since only one assignment is preserved and properly brought forward in defendant’s brief, all others are deemed abandoned under Rule 28, Rules of Practice in the Supreme Court, swpra.
 After retiring to consider its verdict, the jury returned and requested the court to repeat its definitions of voluntary and involuntary manslaughter. The trial judge, “out of an abundance of precaution,” repeated his charge as to second degree murder and then detailed the circumstances which legally reduce that crime to manslaughter, voluntary or involuntary, as the jury might find from the evidence. Defendant assigns this as *365error, contending that its effect was to cause the jury to reconsider second degree murder as a possible verdict and perhaps to find defendant guilty of voluntary rather than involuntary manslaughter. This contention has no merit.
It is true that a judge who is requested by the jury to reiterate his instructions on some particular point is not required to repeat his entire charge. McGaha v. State, 216 Ark. 165, 224 S.W. 2d 534 (1949) ; 23A C.J.S., Criminal Law, § 1376 (d); 53 Am. Jur., Trial, § 942. Indeed, needless repetition is undesirable and has been held erroneous on occasion. 53 Am. Jur., Trial, § 559. But where a careful trial judge, as here, repeats his definition of second degree murder for the express purpose of delineating the law and clarifying its application to factual situations requiring a verdict of voluntary or involuntary manslaughter, his diligence will be commended rather than condemned. Even had the repetition been erroneous, which is not conceded, no prejudice resulted because the jury returned a verdict of voluntary manslaughter and thus acquitted defendant of second degree murder. The matter complained of was entirely harmless and the assignment of error based thereon is not sustained.
Prejudicial error in the trial below has not been shown. The verdict and judgment must therefore be upheld.