[1] In his first assignment of error, the defendant argues that his motion to dismiss the charge of conspiracy to commit robbery with a dangerous weapon should have been allowed for insufficiency of the evidence. He says that Lovely Lorden provided the only eyewitness testimony to the occurrence and that her testimony showed there was no discussion of the crime by any of the men. It .is possible that the men discussed the crime when they were behind Herman’s Place, says the defendant, but this is only speculation. The defendant contends we can just as easily infer that the three men went to Mr. Grady’s home without a shared plan to rob him and that Bo Jones turned a visit to buy alcohol into a robbery. The defendant, relying on United States v. Giunta, 925 F.2d 758 (4th Cir. 1991), says the “mere fact that several people participated in criminal activity does not prove [a] joint plan to do so.”
A criminal conspiracy is an agreement between two or more persons to do an unlawful act or to do a lawful act by unlawful means. State v. Bindyke, 288 N.C. 608, 220 S.E.2d 521 (1975). We said in State v. Whiteside, 204 N.C. 710, 169 S.E. 711 (1933):
Under such conditions, the results accomplished, the divergence of those results from the course which would ordinarily be expected, the situation of the parties and their antecedent relations to each other, together with the surrounding circumstances, and the inferences legitimately deducible therefrom, furnish, in the absence of direct proof, and often in the teeth of positive testimony to the contrary, ample ground for concluding that a conspiracy exists.
We hold that the evidence that defendant met with two other men, one of whom was armed; that the three men drove to the home of the victim; and that the three men then left the vehicle and entered *156the victim’s home, robbed the victim, and shot him is substantial evidence from which the jury could find the robbery was carried out pursuant to a common plan to rob the victim. This supports the finding of guilty of conspiracy to commit robbery with a dangerous weapon. See State v. Abernathy, 295 N.C. 147, 244 S.E.2d 373 (1978).
This assignment of error is overruled.
[2] The defendant next assigns error to the charge. The court in its charge on acting in concert did not instruct the jury that before the defendant could be convicted by proving he was acting in concert, the jury must find that he was actually or constructively present when the crime was committed. The defendant says this was error.
In order to convict a defendant for acting in concert, the State must prove he was actually or constructively present. If all the State’s evidence shows, however, that the defendant was at the scene of the crime, it is not necessary that the court charge the jury that the defendant had to be present. State v. Hunt, 339 N.C. 622, 649, 457 S.E.2d 276, 292-93 (1994), reconsideration denied, 339 N.C. 741, 457 S.E.2d 304 (1995); State v. Gilmore, 330 N.C. 167, 171, 409 S.E.2d 888, 890 (1991); State v. Williams, 299 N.C. 652, 658, 263 S.E.2d 774, 778 (1980).
The defendant, while conceding that presence is not an element of robbery with a dangerous weapon, says it is an element of the State’s case when the State is relying on acting in concert to convict. He contends that by not submitting presence to the jury, the court in effect directed a verdict of guilty and denied him the right to a unanimous jury verdict in violation of his rights under the Constitutions of the United States and North Carolina. Mullaney v. Wilbur, 421 U.S. 684, 44 L. Ed. 2d 508 (1975); State v. Earnhardt, 307 N.C. 62, 296 S.E.2d 649 (1982).
Acting in concert is a doctrine developed to make persons who participate in crimes responsible for criminal activity although they do not do all the acts necessary to constitute the crimes. In charging on acting in concert, the court must explain it adequately for the jury to be able to understand it and apply it to the evidence in the case. If all the State’s evidence shows that the defendant was present when the crime was committed, it is not necessary to explain to the jury that the defendant must be present in order for it to understand and apply the doctrine of acting in concert.
*157We have said in some of our cases that presence is an element of acting in concert. State v. Wilson, 322 N.C. 117, 367 S.E.2d 589 (1988); State v. Williams, 299 N.C. 652, 263 S.E.2d 774 (1980). This does not mean it is an element of the crime that must be proved. So long as the court explains the doctrine so that the jury can apply it, and if the jury’s acceptance of the State’s version of the evidence mandates finding the defendant was present, it is not necessary to tell the jury it must find the defendant was present to find him guilty.
The defendant contends that his presence at the crime scene was disputed because he testified that he knew nothing of the crimes and was asleep in his bed when the crimes were committed. If the jury had believed the defendant, he would have been found not guilty without regard to a charge on acting in concert. The jury accepted the State’s version of the incident. Under this version, the defendant was present at the scene of the crime.
This assignment of error is overruled.
[3] The defendant’s next three assignments of error deal with testimony elicited by the State. No objection was made to this testimony, but the defendant asks us to consider the questions he has raised under the plain error rule. Rule 10(b)(1) of the Rules of Appellate Procedure provides that an assignment of error may be made to the admission of testimony only if exception was taken to its admission at trial. We have said that it places an impossible burden on the trial judge for a party as a matter of trial strategy to allow otherwise incompetent evidence to be admitted and then assign error to it. A trial judge should not have to determine the soundness of a party’s trial strategy and make an objection for him. State v. Oliver, 309 N.C. 326, 307 S.E.2d 304 (1983); State v. Black, 308 N.C. 736, 303 S.E.2d 804 (1983). We shall consider these assignments of error under the plain error rule.
Lovely Lorden testified on direct examination that Bo Jones had beaten her and had stolen things from her and her children. She said she was afraid to leave him because there would be trouble when he found her. The defendant says this testimony was irrelevant to any issue in this case and served only to “smear” Bo Jones and, by association, the defendant.
This testimony was relevant to prove that Ms. Lorden’s fear of Bo Jones was the reason she waited as long as she did before coming forward to tell of the incident. We said in State v. Larrimore, 340 N.C. *158119, 456 S.E.2d 789 (1995), “Where, as here, the witness has been the subject of past acts of violence and thereby has reason to fear another individual, those past acts are relevant to the issue of the witness’ character for truthfulness or untruthfulness.” Id. at 152, 456 S.E.2d at 807. It was not error and certainly not plain error to admit the testimony.
This assignment of error is overruled.
[4] The defendant contends in his next assignment of error that certain questions put to him on cross-examination were improper. The defendant testified on direct examination that in 1991 he was arrested for dealing in marijuana. He said that when the officers came to his home with a search warrant, he showed them the marijuana because he did not want the officers “messing up my house” in a search. On cross-examination, the State elicited testimony that the officers found several weapons, including a sawed-off shotgun, during the raid. The defendant was asked on cross-examination whether he had the gun because he was a drug dealer, and he denied that this was the case.
The defendant says the only reason the prosecutor asked him the question about his using the shotgun in his drug business was to portray him as a “violent thug” who would be inclined to participate in a crime such as the one involved in this case. The question was peripheral to the issues being tried. The defendant had admitted he was a drug dealer, and it was in evidence that a sawed-off shotgun had been found in his home. It could not have had much impact on the jury for the prosecuting attorney to ask whether the shotgun was used in the defendant’s drug dealings, which the defendant denied. The question asked the defendant certainly did not rise to the level of plain error.
This assignment of error is overruled.
[5] In his last assignment of error, the defendant contends hearsay testimony was used against him. He bases this argument on the testimony of Lovely Lorden that on the morning after the murder and robbery, Bo Jones told her that he thought the victim had more money than the three men were able to find. She also testified that he told her that if anyone asked about the shooting, she should say that she did not know anything about it and that if she did not do so, she would go to jail and lose her children.
The testimony in regard to the threat against Ms. Lorden was not introduced for the truth of the statement. It again explained why she *159did not report the offense in a more timely manner. It was not hearsay. N.C.G.S. § 8C-1, Rule 801(c) (1992); State v. Faucette, 326 N.C. 676, 392 S.E.2d 71 (1990).
In regard to Ms. Lorden’s testimony that Bo Jones had told her that he thought the victim had more money than the three men were able to find, it could not have been too prejudicial to the defendant. Ms. Lorden had testified that she drove with three men, including the defendant, to the victim’s home; that the three men went inside with a gun; that she heard two shots; that the three men returned to the automobile; and that thereafter Bo Jones gave her money. The statement by Bo Jones in regard to the amount of money they were able to find added little to the testimony of Ms. Lorden. It did not rise to the level of a fundamental error affecting the basic fairness of the trial. State v. Odom, 307 N.C. 655, 660, 300 S.E.2d 375, 378 (1983).
This assignment of error is overruled.
NO ERROR.