John Fanello appeals from his conviction in the District Court1 of conspiracy to possess with the intent to distribute marijuana in violation of 21 U.S.C. §§ 841(a) and 846. He was sentenced to five years imprisonment with a $15,000 fine. On appeal, Fanello raises the following issues: (1) whether the trial court erred in not granting a mistrial when the prosecutor allegedly violated an order in limine; (2) whether the court erred by not granting a mistrial when the prosecutor arguably commented on Fanello's failure to testify; and (3) whether there was a material variance between the indictment and the proof. We affirm.

The indictment alleged that Fanello and co-defendant Charles Medlen2 had conspired, from August 20, 1978, to November 1, 1978, with numerous other individuals to distribute marijuana. Evidence introduced at trial by the government indicated that a plane load of marijuana was flown from Colombia to an area near Heber Springs, Arkansas. The marijuana was loaded into a truck waiting at a small airstrip. When the plane attempted to take off, the truck carrying the marijuana was knocked over. Law-enforcement officials later discovered the overturned truck, set up surveillance in the area, and subsequently arrested several of the alleged co-conspirators.

The evidence against Fanello comes almost exclusively from the testimony of Mr. and Mrs. Ardell Mears. The Mearses testified that they had been neighbors of Fanello in Florida and were asked by him to locate a place in Arkansas for the purpose of distributing marijuana. Documentary evidence showed that a meeting between Fanello and the Mearses occurred in Memphis, Tennessee, in August of 1978. A paid informant also testified as to the route taken by the plane loaded with marijuana. No question is raised as to the sufficiency of the evidence.

Prior to trial a motion in limine was filed requesting that none of the government witnesses testify about other alleged marijuana transactions involving Fanello. The motion specifically referred to the possibility that Mears might testify to other instances in which he distributed marijuana for the defendant. The trial court ruled that the government could not bring up the issue in its case-in-chief, but that the court might permit the prosecution to introduce it by way of rebuttal, or to use prior instances of distribution of marijuana in cross-examining Fanello if he took the stand.

During the direct examination of Mears, the government elicited a statement from the witness that Fanello was in the marijuana business.3 At that point, the defendant objected and asked for a mistrial, contending that the government's question violated the court's order in limine. The court denied the motion but instructed the jury to disregard the witness's answer.

Trial judges have wide latitude in correcting minor errors that occur at trial. United States v. Pappas, 611 F.2d 399, 406 (1st Cir. 1979). In this case, the District Court did what was necessary to eliminate any possible prejudice that might have resulted from the witness's answer by subsequently telling the jury to disregard the remark and, in effect, sustaining the defendant's objection. Any error was thus rendered harmless. See United States v. Biondo, 483 F.2d 635 (8th Cir. 1973), cert. denied, 415 U.S. 947, 94 S. Ct. 1468, 39 L. Ed. 2d 563 (1974).

Fanello next argues that the prosecutor improperly commented on his failure to take the stand and testify at trial. The comments occurred during closing argument as the prosecutor discussed generally the defendant's attacks on the Mearses' credibility and on their motive for implicating Fanello in the alleged conspiracy.4 The defendant objected to the prosecutor's remarks and requested a mistrial. Although overruling the defendant's objection, the trial court cautioned the prosecutor about the propriety of his comments.5

This Court has stated that "(a) comment by the government upon the failure of the defendant to testify invades his Fifth Amendment privilege against self-incrimination." United States v. Sanders, 547 F.2d 1037, 1042 (8th Cir. 1976), cert. denied, 431 U.S. 956, 97 S. Ct. 2679, 53 L. Ed. 2d 273 (1977). The error may be harmless, however, under all the circumstances, and we will

look to see whether the comment was clearly intended or was of such a nature that the jury would naturally and necessarily view the comment as a reference to the defendant's failure to testify. A second point of inquiry is whether the statements were prejudicial to the defendant.

Id. (citations omitted).

Following the cautionary instruction from the District Court, the prosecutor clarified his earlier remarks.6 In view of the total circumstances, we find that the prosecutor's statements, although of borderline propriety,7 did not constitute reversible error. The statements, rather than referring to the failure of Fanello to testify, concerned the failure of the defense to elicit from the informants on cross-examination ulterior motives for implicating the defendant. In addition, we do not believe the jury would consider the remarks to be an indirect reference to Fanello's failure to testify, nor would the jury "naturally and necessarily" consider the statements as such. See United States v. Thurmond, 541 F.2d 774, 776 (8th Cir. 1976), cert. denied, 430 U.S. 933, 97 S. Ct. 1556, 51 L. Ed. 2d 778 (1977).

Finally, Fanello contends that there was a material variance between the indictment and the proof at trial, such that the District Court should have dismissed the case. The indictment charged that the defendant acted in the Eastern District of Arkansas and elsewhere to conspire to distribute marijuana. Fanello argues that the government never proved he was in the Eastern District of Arkansas during the period of the alleged conspiracy.8 This contention is without merit. To prevail on such a claim, Fanello must establish not only variance, but also that the variance affected his substantial rights. It must go to the heart of the indictment, with the proof offered at trial failing to establish one of the crucial elements of the offense. United States v. Anderson, 618 F.2d 487, 490 (8th Cir. 1980).

In order to be charged with the offense of conspiracy, Fanello need not have been in the Eastern District of Arkansas as long as one of his co-conspirators committed an overt act in that district. In addition, to be guilty of the offense, he need only knowingly contribute his efforts in furtherance of the conspiracy. United States v. Francisco, 410 F.2d 1283, 1288 (8th Cir. 1969); see Nassif v. United States, 370 F.2d 147 (8th Cir. 1966). We conclude that the variance, if there was one, did not affect Fanello's substantial rights. The government's proof established all the crucial elements of the conspiracy.

The judgment is affirmed.