[1] Defendant brings forward eleven assignments of error for our consideration. First, he contends that the trial court erred in permitting the State to ask the firearms identification expert the following two questions:
Q. If you have a .22 caliber pistol and a .22 caliber rifle, both using the same type, the same type of manufactured ammunition, both being fired from the same distance at the same target, what consequence would be the greater velocity that you testified the rifle would have, what consequence would that have in terms of striking the target?
Q. Would you tell the jury, please, how the characteristics of .25 caliber ammunition compare with that of .22 caliber long rifle ammunition?
One of defendant’s arguments about these questions is that they were hypothetical questions requiring the State to incorporate into the questions relevant facts in evidence in the case. We disagree with this contention.
Under well-established law in our jurisdiction, an expert witness may be permitted to render his opinion based on facts not within the expert’s personal knowledge. 1 Stansbury’s North Carolina Evidence § 136 (Brandis Rev. 1973). If the expert is basing his opinion on facts not within his personal knowledge, the facts upon which he grounds his opinion must be set before the jury in a proper manner, leaving to the jury the duty to find the facts. Todd v. Watts, 269 N.C. 417, 152 S.E. 2d 448 (1967). If the facts upon which the expert bases his opinion are within his own knowledge, he may be permitted to state positively his opinion on the matter. 1 Stansbury’s, supra § 136.
In the present case, we find that the two questions were based on the expert’s own personal knowledge and that a hypo*264thetical question was not necessary. The State did not ask the witness’ opinion as to who fired the shot which was fatal to Courtney Rorie; nor did it ask his opinion as to what type of gun fired the fatal shot. In either of these cases, a hypothetical question incorporating facts the jury might find would have been necessary. As the questions were posed, however, the expert witness had only to compare velocities and characteristics of weapons and ammunition, a comparison based solely on his own expert knowledge.
Defendant argues further that these two questions were improper because there was no evidence to support the State’s inference that the pistol used by “James” was of a .22 or .25 caliber type. From the evidence as it is set forth in the record, the identity of “James” as well as of the type of pistol he used were unknown. While we agree with the defendant that the State apparently wanted the jury to find that James’ pistol was of a .22 or .25 caliber type and was, because of the distance of “James” from Courtney Rorie, less likely to have caused the fatal wound, we cannot hold this to be error. The defendant had every opportunity on cross-examination to emphasize the fact that the caliber of “James’ ” pistol was unknown, that there was a possibility that its caliber was much higher, and that a pistol of higher caliber might have caused the fatal wound.
Defendant next assigns as error the trial court’s admission into evidence of nine exhibits (Numbers 3, 4, 16, 17 and 18-22), including the rifle obtained from defendant’s counsel, the only bullet found in the victim’s body, and cartridge cases found in the driveway at 319 Chadwick Road. Defendant’s contention that these items were not relevant is absurd and is rejected. The test, which is clearly met in this case, is that real evidence is relevant if it sheds any light on the circumstances of the crime. See 1 Stansbury’s, supra, § 118.
[2] Furthermore, we reject defendant’s argument that the State failed to establish chain of custody of the rifle between the time of the alleged murder and 29 September, three days later, when it was turned over to the State by defense counsel. The remote possibility that the rifle was switched while in the possession of defendant’s attorney was ruled out by the testimony of the firearms identification expert who positively determined that two of the cartridges found in the driveway of 319 Chadwick Road had been fired from that particular rifle.
*265Defendant’s further contention concerning the introduction of real evidence is that the State failed to establish that the items introduced into evidence were involved in the incident giving rise to the trial.
In State v. Harbison, 293 N.C. 474, 238 S.E. 2d 449 (1977), the Supreme Court noted that there are no simple standards for determining whether an object offered in evidence has been adequately identified as being the same object involved in the incident giving rise to the trial and shown to have been unchanged in any material respect. As a result, the trial judge must exercise sound discretion in determining the standard of certainty required to show that the item offered into evidence is the same as that involved in the incident. Id. In the case before us, we find that the trial court did exercise sound discretion in allowing the State to introduce the several items of real evidence.
The record reveals that the evidence was held under lock and key by the Property Officer of the Durham Police Department. He checked the items out twice, once to his supervisor, the firearms identification expert, and once to a laboratory technician. Both of these men testified. Michael Jennings, the laboratory technician, identified the fired cartridges (Exhibits 18-22), the small lead particles (Exhibit 16), and the bullet (Exhibit 17) from the victim’s body as the ones either found at the scene of the shooting or retrieved from the medical examiner. Curtis, the firearms expert, positively identified the rifle (Exhibit 3), and cartridges and a cartridge case (Exhibit 4). Furthermore, Louis Dan-ford, formerly of the Durham County Sheriffs Department, testified that the rifle (Exhibit 3) introduced into evidence was the one he received from defendant’s counsel and that, further, the nine live rounds of ammunition (Exhibit 4) were removed from that rifle. Based on the foregoing, we find no merit to defendant’s contention that the State failed to identify these objects as being connected to the incident.
[3] As his third assignment of error, defendant contends that the trial court erred in failing to dismiss the case at the close of the State’s evidence and at the close of all of the evidence and in denying defendant’s motion to set aside the jury verdict. The basis of all three of defendant’s motions was that there was insufficient evidence to support his conviction for any degree of homicide.
*266Upon a motion to dismiss in a criminal action, all of the evidence favorable to the State must be deemed true; discrepancies and contradictions therein are disregarded, and the State is entitled to every favorable inference of fact reasonably deduced from the evidence. State v. Witherspoon, 293 N.C. 321, 237 S.E. 2d 822 (1977). Based on this principle, this Court can find no error in the trial court’s denials of defendant’s motion. A reading of the facts set forth in this opinion shows that there was substantial evidence from which a jury might conclude that the defendant fired the shot which caused Rorie’s death. The fact that there was some evidence that another man was firing a pistol at the deceased does not negate, for purposes of defendant’s motions, the evidence implicating defendant.
[4] Defendant’s fourth assignment of error pertains to the exclusion of certain evidence he sought to introduce in order to show the character of the deceased as being that of a dangerous and violent person. The excluded evidence, elicited from Rachel Jones, defendant’s wife, was to the effect that Courtney Rorie, at some point in the past, had shot up the window of Rachel Jones’ house and, when she had attempted to go call the sheriff, the deceased had driven up behind her and had shot the tires of her automobile; that Rorie had once gone into Gracey Rorie’s house and destroyed many of its furnishings; that, upon Rorie’s return to Durham, he threatened to remove all the furniture from the house; that defendant’s wife and others in her family had gone to a lawyer and then to law enforcement officials, including a district court judge, to stop Rorie’s threatened efforts; and that a warrant for Rorie’s arrest on earlier charges had been drawn.
In a prosecution for homicide or for assault and battery, where there is evidence tending to raise the issue of self-defense, evidence of the character of the deceased as a violent and dangerous fighting man is admissible if (1) such ■ character was known to the accused or (2) the evidence is wholly circumstantial or the nature of the event is in doubt. 1 Stansbury’s, supra, § 106. In the instant case, we are concerned only with the question of whether the particular acts of Courtney Rorie’s violence, related by Rachel Jones, were known to the defendant. While it is hard to find that defendant did not know of some of the incidents about which his wife attempted to testify, we must, after studying the record, so conclude. Rachel Jones did not testify that defendant *267knew of Rorie’s destruction of furniture or of his shooting out the window of her house and the tires of her car; defendant was apparently not among the family members who sought legal help and was, as far as the record reveals, unaware of those efforts. Most importantly, defendant, who took the stand in his own behalf, failed to testify to the very incidents about which his wife sought to testify. We cannot hold it error that the trial court refused to admit this testimony concerning the victim.
There was testimony elicited from Rachel Jones which would have confirmed defendant’s testimony concerning Rorie’s violent and dangerous character. This testimony, however, was merely cumulative, and its exclusion was not erroneous.
Defendant’s fifth assignment of error is related to additional evidence concerning Rorie’s violent and -dangerous character. Defendant contends that the trial court erred in refusing to admit documents from the divorce file of Gracey and Courtney Rorie. The record shows that the file contained a Complaint for a Divorce from Bed and Board and Motion for Temporary Restraining Order; Gracey Rorie’s Affidavit to bring action as a pauper; Certificate of Counsel in support of the affidavit; an Order allowing Gracey Rorie to proceed in forma pauperis; an Order to Show Cause; a Temporary Restraining Order; Courtney Rorie’s handwritten answer; a civil summons; an Order granting, among other things, a divorce from bed and board; a Motion for Contempt; and an Order for the arrest of Rorie.
Obviously many of these documents were .not relevant to defendant’s cause. Once the objection to their admission was sustained, defendant should have reoffered the unobjectionable parts. See Branch v. Dempsey, 265 N.C. 733, 145 S.E. 2d 395 (1965). This he failed to do. Furthermore, it does not appear from the record that defendant was aware of the incidents- of Rorie’s violence which were related in the documents. Hence, the documents were not admissible to show Courtney Rorie’s character as a violent and dangerous man. 1 Stansbury’s, supra.
[5] As his sixth assignment of error, defendant contends that the trial court erred in charging the jury on how to determine the credibility of witnesses interested in the outcome of the trial. The record reveals that the trial court charged the jury as follows:
*268Now, you may find that a witness or witnesses are interested in the outcome of the trial and in deciding whether or not to believe such a witness then you should take into account the interest that he or she may have, and [if after doing so you believe that testimony in whole or in part, then you should treat what you believe the same as you would treat other believable evidence.]
DEFENDANT’S EXCEPTION NO. 13
We do not believe, as defendant contends, that this instruction invaded the province of the jury to assign different weight and importance to the testimony of the various witnesses. Prior to this instruction the court had charged:
You are also the sole judges of the weight to be given any of the evidence presented, and by this I mean, if you decide certain evidence is believable you must then determine the importance of that evidence in light of all the other believable evidence presented during the trial.
In reviewing this as well as the charge about which defendant complains, we can find no error in this portion of the charge.
[6] Next defendant assigns as error the following instructions concerning second degree murder:
I instruct you, Members of the Jury, that in order for you to find this defendant guilty of second degree murder and in order for the State to prevail in that, the State must prove two things beyond a reasonable doubt, which are
[First, that this defendant, Alvin Eugene Jones, on or about the 26th day of September, 1980, intentionally and without justification or excuse, such as while acting in self-defense, and with malice shot Courtney Rorie with a deadly weapon.]
Exception No. 14
I have used the word malice ... [in saying that] the acts must be done with malice. I instruct you that malice means not only hatred or ill will or spite, as it is ordinarily *269understood, that, of course, is malice, [but the word malice also means that condition of mind which prompts a person to take the life of another intentionally or to intentionally inflict a wound with a deadly weapon upon another which proximately results in his death, without just cause, excuse or justification, such as, through acting in self-defense,]
Exception No. 16
Additionally, the trial court, in redefining second degree murder, included the following instruction:
First, that the defendant intentionally and without justification or excuse and with malice shot Courtney Rorie with a deadly weapon. [When I use the term without justification or excuse I’m referring to self-defense or the doctrine of self-defense.]
DEFENDANT’S EXCEPTION NO. 20
Defendant contends that, by these confusing instructions, the court charged that acting in self-defense would be an intentional shooting without justification or excuse. While we concede that, according to the court reporter’s punctuation, the instructions were not well stated, we find, in view of the rest- of the charge, that defendant suffered no prejudicial error.
The law in North Carolina is well-established that, although it may not be necessary to kill to avoid death or great bodily harm, a person may kill if he believes it to be necessary, and he has reasonable grounds for believing it necessary, to save himself from death or great bodily harm. State v. Gladden, 279 N.C. 566, 184 S.E. 2d 249 (1971). The reasonableness of his belief is to be determined by the jury from the facts and circumstances as they appeared to the defendant at the time of the killing. Id.
In the instant case, in addition to the charge set forth above, the trial court clearly stated that a killing would be excused entirely on the ground of self-defense if certain circumstances existed. Given these instructions, we conclude that error, if any, in this portion of the charge was not prejudicial to defendant.
[7] Defendant’s eighth assignment of error pertains to another exception he took to the jury charge. He contends that the follow*270ing original instruction, repeated when the judge' redefined second degree murder, allowed the jury to infer defendant’s intent from circumstances without requiring the jury to find the circumstances specifically:
Now, I have said that the act must have been intentional. Intent is the exercise of an intelligent will. Intent is a condition or emotion of the mind which is seldom, if ever, capable of direct proof, but the intent of a person is usually deduced from the acts, the declarations, and circumstances known to the person charged with having that intent. [One arrives at the intent of another person by such just and reasonable deductions from the circumstances proven as a reasonably prudent person would ordinarily draw therefrom.]
Exception No. 15,
We can find no merit in defendant’s contention. It is certainly within the province of the jury to determine what the circumstances of the killing were; as the charge reflects, once the jury has done this, it must make reasonable deductions of defendant’s intent from those circumstances. The jurors are not required to agree on all the circumstances; different persons may reasonably deduce intent from slightly variant circumstances. In overruling this assignment of error, we note that the North Carolina Pattern Jury Instructions contain this instruction on intent almost verbatim. North Carolina Pattern Jury Instructions for Criminal Cases, § 206.30.
[8] As his next assignment of error, defendant contends that the trial court erred in instructing the jury on the inference it might draw if it found beyond a reasonable doubt that defendant intentionally inflicted the fatal wound upon Courtney Rorie. The trial court charged:
Now, if the State proves beyond a reasonable doubt that the defendant intentionally killed Courtney Rorie with a deadly weapon or that he intentionally inflicted a wound upon him with a deadly weapon that proximately caused his death, then you may infer first, that the killing was unlawful, and second, that the killing was done with malice, but you are not compelled to draw such an inference. You may consider this along with all the other facts and circumstances in *271determining whether the killing was unlawful and whether it was done with malice. If the killing was unlawful and was done with malice, then the defendant would be guilty of second degree murder, nothing else appearing.
Defendant’s argument is that, because self-defense was an issue in the case, the trial court should have instructed about the permissibility of the inferences of unlawfulness and malice with reference to the evidence about self-defense. Defendant asserts that neither inference could be drawn until the jury determined beyond a reasonable doubt that the defendant did not act in self-defense.
In Mullaney v. Wilbur, 421 U.S. 684, 95 S.Ct. 1881, 44 L.Ed. 2d 508 (1975), the Supreme Court held that the Due Process Clause of the Fourteenth Amendment to the U.S. Constitution requires the prosecution to prove beyond a reasonable doubt the absence of heat of passion on sudden provocation when the issue is properly presented in a homicide case. Thereafter, in State v. Hankerson, 288 N.C. 632, 220 S.E. 2d 575 (1975), rev’d. on other grounds, 432 U.S. 233, 97 S.Ct. 2339, 53 L.Ed. 2d 306 (1977), our Supreme Court held that the requirement that a criminal defendant prove that he acted in self-defense violated the Due Process Clause. As the Court interpreted the Mullaney ruling, our courts are not precluded from utilizing traditional presumptions of malice and unlawfulness.
It precludes only utilizing them in such a way as to relieve the state of the burden of proof on these elements when the issue of their existence is raised by the evidence. The presumptions themselves, standing alone, are valid and, we believe, constitutional [Citations omitted]. Neither, by reason of Mullaney, is it unconstitutional to make the presumptions mandatory in the absence of contrary evidence nor to permit the logical inferences arising from facts proved (killing by intentional use of a deadly weapon).
Id. at 649, 220 S.E. 2d at 588.
Citing these cases, defendant argues that the trial court’s instructions set forth mandatory presumptions of unlawfulness and malice and that where, as here, there was evidence of self-defense, such presumptions were not constitutionally acceptable. We disagree with the defendant’s argument.
*272First, the presumptions of unlawfulness and malice were not mandatory. The jurors were told that they were not compelled to draw such inferences and that they could consider the inference along with other facts and circumstances in determining whether the killing was done unlawfully and with malice. Secondly, the trial court had already instructed the jury that, in order to find defendant guilty of second degree murder, it had to find that he had intentionally, without justification or excuse such as self-defense, shot Rorie with a deadly weapon. Finally, the trial court, in instructing on the issue of self-defense, clearly placed on the State the burden of proving beyond a reasonable doubt that the defendant did not act in self-defense. When we read the instructions as a whole, we can find no violation of the Mullaney and Hankerson principles.
Defendant also asserts that, when self-defense is at issue in a case, the presumption of malice and unlawfulness from a shooting found to be intentional is inconsistent with due process of law. The reason for this, according to defendant, is that the presumption violates the “more likely than not” standard:
[A] criminal statutory presumption must be regarded as “irrational” or “arbitrary,” and hence unconstitutional, unless it can at least be said with substantial assurance that the presumed fact is more likely than not to flow from the proved fact on which it is made to depend.
Leary v. United States, 395 U.S. 6, 36, 89 S.Ct. 1532, 1548, 23 L.Ed. 2d 57, 82 (1969). We reject defendant’s argument that the presumptions of malice and unlawfulness are not “more likely than not” to flow from proof of an intentional shooting. Leary, which held unconstitutional a statutory presumption that one in possession of marijuana had knowledge that the substance was imported into this country, does not apply. Defendant’s ninth assignment of error is overruled.
[9] Defendant’s tenth assignment of error is based on the exception he took to the following instructions on the third aspect of the doctrine of self-defense:
And the third thing is that the defendant was not the aggressor in the incident. If he voluntarily and without any provocation entered into the fight, [he making the first move.]
*273Exception No. 18
then he would the aggressor unless he thereafter attempted to abandon the fight and gave notice to Courtney Rorie that he was doing so.
Contrary to defendant’s contentions, we do not find that this instruction confused the jury as to this aspect of the law of self-defense. The right of self-defense is available only to one who is without fault. If a person voluntarily, ie. aggressively and willingly, without legal provocation or excuse, enters into a fight, he cannot invoke the doctrine of self-defense unless he abandons the fight, withdraws from it, and gives notice to his adversary that he has done so. State v. Davis, 225 N.C. 117, 33 S.E. 2d 623 (1945). We find that the instructions set forth adequately reflect the law on this matter.
[10] Defendant’s final contention is that the trial court erred when it instructed the jurors that it was their duty to remember and consider the convictions urged by counsel in their arguments. The trial court obviously committed a minor lapsus linguae when it referred to “convictions” instead of “contentions.” In view of the rest of the charge concerning the jury’s duty to remember and consider all the evidence and in view of the fact that the lapsus linguae affected equally the prosecution and defense, we find no error.
Having reviewed the record of defendant’s trial and the contentions he has brought forward, this Court finds that defendant received a fair trial, free from prejudicial error.
No error.
Judges Clark and Whichard concur.