Defendant brings forth and argues fourteen assignments of error.
[1, 2] The first, third and fourth assignments of error relate to the admission of certain testimony over objection. A lay witness characterized the gunshot wound suffered by deceased as a “nasty” wound and stated that the gun was fired so close to deceased that the pellets did not have a chance to spread. While the trial judge would have been justified in striking these statements as conclusions of the witness, his failure to do so does not, under the circumstances, constitute reversible error. The witness described the size and location of the stomach wound and stated that he saw the deceased’s intestines coming through the wound. His description of the wound as “nasty” was little more than a shorthand statement of the facts. Other exceptions grouped under this assignment of error relate to testimony of witnesses as to incriminating statements which they overheard defendant make at the time of the shooting or shortly thereafter. This evidence was competent. “It is well settled law in this jurisdiction that in a criminal prosecution admissions of fact by a defendant pertinent to the issue which tend to prove his guilt of the offense charged are competent against him. State v. Porth, 269 N.C. 329, 153 S.E. 2d 10; State v. Woolard, 260 N.C. 133, 132 S.E. 2d 364; State v. Abernethy, 220 N.C. 226, 17 S.E. 2d 25; State v. Lawhorn, 88 N.C. 634.” State v. Robbins, 275 N.C. 537, 546, 169 S.E. 2d 858, 864.
*193  In his second assignment of error defendant attacks the admission in evidence of a single color photograph of the body of deceased. The record indicates that a photograph -was marked for identification as a State’s exhibit and a witness was asked if it fairly and accurately represented the wound on the deceased’s stomach and the porch where deceased fell. However, the record does not show that this photograph was offered or received in evidence and no photograph has been filed with the clerk of this Court as required by Rule 19 (j), Rules of Practice in the Court of Appeals of North Carolina. It is noted, however, that photographs are admissible in evidence to illustrate the testimony of a witness, when properly authenticated by the witness as a correct portrayal of conditions which he observed and which he relates in his testimony. State v. Atkinson, 275 N.C. 288, 167 S.E. 2d 241, and cases cited. The fact a photograph is in color does not affect its admissibility. State v. Hill, 272 N.C. 439, 158 S.E. 2d 329.
Under his fifth assignment of error defendant states that the court erred in refusing his motions for nonsuit and his motion for a mistrial.
Defendant now concedes that there was sufficient evidence to go to the jury on the charge of murder in the first degree and the lesser included offenses, but he insists that the court erred in denying his motion for a mistrial. Suffice to say, no grounds appear which would have justified an order for a mistrial.
 In questioning defendant concerning his prior criminal record, the solicitor asked: “On August 1st, 1965, you were tried for Assault and Battery with intent to kill in Winnsboro, South Carolina, were you not?” Defendant’s objection to the question was overruled, and this constitutes his sixth assignment of error. The question was improper; defendant’s objection should have been sustained and the jury should have been instructed to disregard the question. State v. Williams, 279 N.C. 663, 185 S.E. 2d 174. However, the narration of defendant’s answer, as it appears in the record, is not responsive to the question and it appears that he never admitted that he had been tried or convicted for the offense of assault and battery with intent to kill. Under these circumstances, the question was not sufficiently harmful to require a new trial.
 Defendant’s seventh assignment of error is to the refusal of the court to permit a witness to testify that she saw deceased *194assault her brother with a pistol and a knife on an occasion prior to 25 November 1971. This was not error. Evidence of prior threats and of incidents of violence on prior unrelated occasions are ordinarily competent, but only if the defendant was present when the incident occurred, or had knowledge of the incident prior to the alleged homicide or assault. State v. Johnson, 270 N.C. 215, 154 S.E. 2d 48; Nance v. Fike, 244 N.C. 368, 93 S.E. 2d 443; State v. Blackwell, 162 N.C. 672, 78 S.E. 316. Defendant was not present at the time of the assault described by the witness and there is no evidence that the act was ever communicated to defendant. The witness stated that she had never had a conversation with defendant about the incident and did not know whether her brother or anyone else had told him about it.
 Through his eighth assignment of error, defendant challenges the admission of testimony by a police officer as to certain in-custody statements. While the record indicates defendant was warned of his constitutional rights before he was questioned by the officers, it does not show that he was given a voir dire hearing at the trial for the purpose of determining whether he waived counsel and voluntarily made the statements. However, the statements were not offered to prove the State’s case, but to impeach defendant’s credibility. They were allowed only after defendant testified and denied that he had made the statements. The use of defendant’s in-custody statement to impeach and contradict his testimony was not error. Harris v. New York, 401 U.S. 222, 91 S.Ct. 643, 28 L.Ed. 2d 1 (1970); State v. Bryant, 280 N.C. 551, 187 S.E. 2d 111.
Defendant’s fourteenth assignment of error encompasses an exception that is simply formal in nature and needs no discussion. All other assignments of error relate to portions of the charge. These assignments of error have been reviewed and are overruled.
We find that defendant had a fair trial free from prejudicial error.
Judges Hedrick and Vaughn concur.