GRIFFIN, J.

We have consolidated the appeals of these cases to consider related issues regarding the severance of trials of codefendants in criminal cases. In People v Hana, we address the question whether the trial court should have granted defendant's motion for severance in the context of the presentation of allegedly antagonistic defenses. In People v Rode and People v Gallina, the question presented is whether the dual-jury procedure utilized in these cases unduly prejudiced the defendants.

We hold, in line with MCL 768.5; MSA 28.1028 and MCR 6.121(D), that the decision to sever or join defendants lies within the discretion of the trial court. Severance is mandated under MCR 6.121(C) only when a defendant demonstrates that his substantial rights will be prejudiced and that severance is the necessary means of rectifying the potential prejudice.

Judged by this standard, we find in People v Hana that the trial court did not abuse its discretion in denying defendant's motion for severance. The decision of the Court of Appeals is therefore affirmed.

In People v Rode and People v Gallina, we conclude that the defendants have not demonstrated prejudice to their substantial rights. The use of separate juries is a partial form of severance to be evaluated under the standard, set forth above, applicable to motions for separate trials. The issue is whether there was prejudice to substantial rights after the dual-jury procedure was employed. On the basis of a review of the record, we find no demonstrated prejudice to either defendant under these circumstances. The Court of Appeals conclusion to the contrary is therefore reversed.

I

A. PEOPLE v HANA

Defendant Durid Hana was convicted of possession of over 650 grams of cocaine, MCL 333.7403(2)(a)(i); MSA 14.15(7403)(2)(a)(i), and delivery of over 225 but less than 650, grams of cocaine. MCL 333.7401(2)(a)(ii); MSA 14.15(7401)(2)(a)(ii).

Defendant and his brother, Kafan, were arrested following a controlled narcotics purchase in January, 1988, that took place at the Sterling Heights home in which the defendant and his brother lived with their parents and siblings.

At trial, it was established that the drug transaction arose out of a conversation between James Hornburger and Raed Alsarih at the Sterling Heights High School where they were students. Hornburger approached Alsarih about obtaining twelve ounces of cocaine for Stephen Putnam (an undercover narcotics police officer). Alsarih confirmed the transaction after contacting his "connection," Kafan. Hornburger, Putnam, and Alsarih drove to Kafan's home. Alsarih went to the door and spoke with defendant. Defendant contacted Kafan by beeper and reported that Kafan would be back in fifteen minutes. Putnam, Alsarih, and Hornburger drove to a parking lot, waited, and then returned to the Hana home. Defendant told Alsarih that Kafan had not yet returned. Putnam then dropped Alsarih and Hornburger off at Alsarih's home, with instructions to call him when Kafan arrived. Alsarih eventually called Putnam and reported that Kafan would have the twelve ounces of cocaine at 7:00 P.M.

Putnam picked up Alsarih and Hornburger and they again drove to the defendant's home. When they arrived, nobody answered the door. After waiting a minute or two, they saw Kafan drive up and Alsarih and Kafan went into the house together.

According to Alsarih, testifying pursuant to a plea bargain, he went to a back bedroom with Kafan where defendant was sleeping. Defendant awoke when Kafan turned on the light. While Kafan opened a safe, defendant asked Alsarih whether the person outside was a police officer and whether Alsarih had dealt with him before. Kafan removed a plastic bag from the safe, mixed it with the contents from some other bags and gave it to Alsarih. Alsarih was given an "eight ball" (one-eighth ounce of cocaine), which was to be given to Hornburger for his part in the transaction. They then proceeded to the door and Kafan watched while Alsarih went out to Putnam's car. As Putnam opened the door, Alsarih explained that he had been instructed not to get in. Putnam then put his car keys on top of the car and refused to leave. Defendant was watching from the living room window. Alsarih then got in the back seat, gave the bag of cocaine to Putnam, and Putnam handed him $12,500 in marked money. Putnam signaled to a surveillance team, which moved in and arrested Hornburger, Alsarih, Kafan, and defendant.

A subsequent search of the home, pursuant to a search warrant, disclosed that the safe contained three kilograms of cocaine, miscellaneous jewelry and papers, a telephone recorder, and a telephone beeper. Both Kafan and defendant initially denied knowing the combination to the safe. However, Kafan later supplied the combination, and defendant admitted that the safe belonged to him (defendant).

Both defendant and Kafan filed pretrial motions for separate trials. Following a hearing, the trial court denied severance. Kafan's attorney renewed the motion during trial after the prosecution rested its case, but the trial judge again denied the motion. Defendant was tried jointly with Kafan before a jury in February 1989. Neither the defendant nor his brother testified. Defendant was convicted, as charged (as was Kafan).

The trial court imposed a prison term of from ten to thirty years for the delivery count and a nonparolable life sentence for possession of 650 or more grams of cocaine. Defendant appealed, alleging in pertinent part that the trial court erred in denying his motion for a separate trial. The Court of Appeals rejected defendant's severance claim and affirmed his conviction. Unpublished opinion per curiam, issued March 20, 1992 (Docket No. 119380).

Defendant's motion for a rehearing was denied, and he then filed a delayed application for leave to appeal with this Court. In an order dated June 28, 1993, we granted leave to appeal, consolidating this case with People v Rode and People v Gallina, for consideration of related issues concerning the severance of trials of criminal defendants. 442 Mich. 935.

B. PEOPLE v RODE AND PEOPLE v GALLINA

Following a joint trial before separate juries, defendants Eric Rode and Aldo Gallina were convicted of second-degree murder, MCL 750.317; MSA 28.549, and possession of a firearm during the commission of a felony, MCL 750.227b; MSA 28.424(2), stemming from the killing of a young man in Dearborn in 1989. An explanation of the relevant events is set forth in the Court of Appeals opinion:

On July 2, 1989, defendants were riding around in a Chevrolet Camaro with some high school friends. The Camaro was owned by defendant Gallina's cousin, Frank Kuhne. Defendant Gallina, age fifteen, was seated in the front passenger seat, and defendant Rode, age sixteen, was in the back seat on the passenger side. A Ford Mustang pulled beside the Camaro and the Mustang's occupants, Edward and Charles Schramek, indicated that they wanted to race. When the cars were side by side, Charles and the other occupants of the Camaro began shouting at each other. Charles shouted, "You're lucky we don't pull our gun out and shoot you." At that point, defendant Gallina pulled a gun from the front panel of the car, where he knew his cousin kept it, and fired it out the window more than once. Defendant Rode then took the gun from defendant Gallina. Defendant Gallina testified that defendant Rode said, "If you are not going to shoot at them, I will." Defendant Rode fired the gun toward the tires of the Mustang.

Defendant Rode testified that after he shot toward the tires, he gave the gun back to defendant Gallina, who shot the gun again. Defendant Rode then reloaded the gun with bullets supplied by defendant Gallina. The Mustang continued to follow the Camaro. The driver of the Camaro stopped the car suddenly, and, as the Mustang passed the driver's side of the Camaro, one of the defendants pulled himself up out of the passenger-side window and shot several times over the roof of the Camaro into the passenger side of the Mustang. Charles was killed by one of these shots.

Each defendant testified after the prosecutor rested. Each denied firing the gun over the roof as the Mustang passed the Camaro, and each claimed that the other defendant fired the gun. Jonathan Warmack, who was driving the Camaro, testified that defendant Gallina did not fire the gun when the Mustang was passing. Warmack also testified that after the Mustang passed by, defendant Rode said, "I know I hit him." Brad Andrews, who was in the back seat of the Camaro on the driver's side, made a statement to the police wherein he said that defendant Rode fired the gun over the roof as the Mustang was passing. At trial, Andrews testified that he did not see defendant Rode fire the gun as the Mustang passed, but he did see defendant Gallina reach out the window and fire the gun once the Mustang had passed. James Kelly, who was seated in the middle of the Camaro's back seat, testified that defendant Gallina fired the gun over the roof as the Mustang was passing, and then defendant Rode leaned out the window and fired the gun as the Mustang drove off. [ 196 Mich. App. 58, 61-62; 492 N.W.2d 483 (1992).]

The defendants were charged with first-degree (premeditated) murder and with possession of a firearm during the commission of that felony. MCL 750.316, 750.227b; MSA 28.548, 28.424(2). As juveniles, they were processed under the automatic-waiver provisions. MCL 600.606, 764.1f, 712A.2(a)(1); MSA 27A.606, 28.860(6), 27.3178(598.2)(a)(1).

Before trial, both defendants moved for severance, claiming that separate trials were necessary because of antagonistic defenses. Following two hearings on the issue, the trial court ruled that there would be a single trial at which separate juries would be impaneled.

A two-jury joint trial took place in November, 1989. Each jury returned a verdict finding its defendant guilty of second-degree murder and felony-firearm. The trial court conducted a dispositional hearing pursuant to MCL 769.1(3); MSA 28.1072(3); MCR 6.931, and concluded that defendants should be sentenced as adults. The court imposed sentences of life in prison for second-degree murder, as well as the mandatory two-year consecutive terms for felony-firearm.

Both defendants appealed, and the Court of Appeals reversed defendants' convictions, finding in pertinent part that the trial court erred in its decision to try the cases jointly with dual juries.

The prosecutor filed separate applications for leave to appeal with this Court. In an order entered June 28, 1993, we granted leave to appeal, limited to the issue whether the trial court erred in denying defendant's motion for separate trials. We further ordered that these cases be argued and submitted to the court together with the case of People v Hana, 442 Mich. 935.

II

We granted leave to appeal in the instant cases to revisit an issue that has not been authoritatively addressed by this Court since 1976 — the appropriate standard for severance of the trials of codefendants in criminal cases. Our reexamination is prompted, in part, by issuance of a recent United States Supreme Court decision, Zafiro v United States, 506 U.S. 534; 113 S Ct 933;

122 L Ed 2d 317 (1993), which addresses the issue at hand. The prosecutors in the instant cases urge that we adopt the severance standard set forth in Zafiro. Our approach begins with a chronological overview of Michigan law as it pertains to severance.

The question of joinder and severance of defendants in criminal prosecutions in Michigan is addressed by statute. MCL 768.5; MSA 28.1028 provides that "[w]hen two or more defendants shall be jointly indicted for any criminal offense, they shall be tried separately or jointly, in the discretion of the court."

Early decisions of this Court that interpreted the joinder statute (or earlier versions of it) emphasized not only the discretionary nature of a joinder decision but also uniformly required a defendant who moved for severance to demonstrate prejudice that would arise out of joinder. For instance, in People v Mullane, 256 Mich. 54, 56; 239 N.W. 282 (1931), the defendant's counsel moved for a separate trial for his client, for the reason that he "has a good and meritorious defense and believes that his said defense would be prejudiced if he is compelled to go to trial with the other defendants." On appeal, it was held that the trial court did not abuse its discretion in denying the motion, because "[n]o affidavit, stating facts on which the court might determine whether the defenses relied on were inconsistent with each other and a joint trial might result in prejudice to one or more of them, was presented." Id. See also People v Garska, 303 Mich. 313; 6 N.W.2d 527 (1942); People v Kynerd, 314 Mich. 107; 22 N.W.2d 90 (1946); People v Krugman, 377 Mich. 559; 141 N.W.2d 33 (1966).

In People v Schram, 378 Mich. 145, 156; 142 N.W.2d 662 (1966), the Court added to prior authority the requirement that "in the absence of a showing of prejudice to substantial rights of the accused," a trial court's severance decision will not be reversed.

In 1976, the Court decided People v Hurst, 396 Mich. 1; 238 N.W.2d 6 (1976), a pivotal case with regard to the present appeals because it focused on the standard for severance in the context of antagonistic defenses. In Hurst, the defendant and his wife were jointly tried and convicted by a jury of manslaughter with regard to the death of their young daughter. A motion by the prosecution for a joint trial was granted over an objection that the defenses were antagonistic. On appeal, this Court held that the trial judge erred in ordering a joint trial. The Hurst Court began its analysis with the general rule that a defendant does not have a right to a separate trial. Joinder of defendants for trial is usually within the discretion of the court. However, "[a] severance should be granted when the defenses of several defendants jointly indicted are antagonistic to each other." 5 Wharton's Criminal Law and Procedure, § 1946; Anno: Right to severance where two or more persons are jointly accused, 70 ALR 1171.

The commentary accompanying the American Bar Association Standards Relating to Joinder and Severance states: "it has long been the view that defendants joined for trial should be granted a severance whenever their defenses are antagonistic to each other." [ Id., p 6.]

While neither Kelker nor Hurst directly accused the other of causing Evelyn's death, the tendency of the testimony of each was to accuse the other of her death. By insisting on a joint trial, the state succeeded in pitting one defendant against the other, each trying to save himself at the detriment of the other.

* * *

Hurst was aware of Kelker's extrajudicial statements incriminating him and correctly anticipated that if the two were tried jointly she would testify to exculpate herself and incriminate him. The judge erred in ordering a joint trial over Hurst's objection. [ Id., p 9.]

We hold that in the circumstances Hurst was denied a fair trial. A defendant is entitled to a trial separate and apart from a codefendant who it appears may testify to exculpate himself and incriminate the defendant seeking a separate trial. [ Id., p 4.]

Three months after Hurst was decided, the Court in People v Carroll, 396 Mich. 408, 414; 240 N.W.2d 722 (1976), affirmed a joint trial, reiterating the principles of Schram, supra:

Statutory authority for the exercise of the court's discretion (MCL 768.5; MSA 28.1028) and case law establishing a strong policy in favor of joint trials are acknowledged by defendants. There must be an affirmative showing of prejudice to substantial rights of the accused. People v Schram, 378 Mich. 145; 142 N.W.2d 662 (1966). The motion here was based upon an allegation of inconsistent defenses. The record discloses that the defenses differed but were not inconsistent and no statement was used by one defendant against another. No abuse of discretion is demonstrated. [See also People v Wakeford, 418 Mich. 95, 119; 341 N.W.2d 68 (1983).]

In 1989, a new provision regarding joinder and severance was added to chapter 6 of the revised Michigan Court Rules. MCR 6.121 provides for permissive joinder and conditional severance:

(A) Permissive Joinder. An information or indictment may charge two or more defendants with the same offense. . . . [T]wo or more informations or indictments against different defendants may be consolidated for a single trial whenever the defendants could be charged in the same information or indictment under this rule.

* * *

(C) Right of Severance; Related Offenses. On a defendant's motion, the court must sever the trial of defendants on related offenses on a showing that severance is necessary to avoid prejudice to substantial rights of the defendant.

(D) Discretionary Severance. On the motion of any party, the court may sever the trial of defendants on the ground that severance is appropriate to promote fairness to the parties and a fair determination of the guilt or innocence of one or more of the defendants. Relevant factors include the timeliness of the motion, the drain on the parties' resources, the potential for confusion or prejudice stemming from either the number of defendants or the complexity or nature of the evidence, the convenience of the witnesses, and the parties' readiness for trial.

As indicated by the staff comment accompanying MCR 6.121(C), the new court rule incorporated the principles set forth in prior case law:

Subrule (C) sets forth a defendant's entitlement to a separate trial, if not obtainable pursuant to subrule (B), on a showing that it "is necessary to avoid prejudice to substantial rights of the defendant." This standard is taken from People v Schram, 378 Mich. 145, 156 (1966), and People v Carroll, 396 Mich. 408, 414 (1976). It is said to reflect a strong policy in favor of joint trials set forth in MCL 768.5; MSA 28.1028 and found in case law. The right of a defendant to a fair trial and other substantial rights, however, may necessitate severance. See, for example, People v Hurst, 396 Mich. 1, 4 (1976), stating that a defendant is entitled to a separate trial if it appears that a codefendant "may testify to exculpate himself and incriminate the defendant seeking a separate trial."

In 1993, while the defendants' applications were pending in this Court, the United States Supreme Court decided Zafiro, supra, in which it addressed the matter of severance in the context of mutually antagonistic defenses. The four defendants in Zafiro were jointly tried pursuant to rule 8(b) of the Federal Rules of Criminal Procedure, which provides that defendants may be charged together "if they are alleged to have participated in the same act or transaction or in the same series of acts or transactions constituting an offense or offenses." Id., 122 L Ed 2d 322-323. The defendants argued that their defenses were mutually antagonistic and moved for severance under rule 14, which specifies that "[i]f it appears that a defendant or the government is prejudiced by a joinder of . . . defendants . . . for trial . . . the court may order an election or separate trials of counts, grant a severance of defendants or provide whatever other relief justice requires." Id., 122 L Ed 2d 324. The district court denied the motions, and each defendant was convicted of various drug-related offenses.

The Supreme Court ultimately affirmed the denial of severance. The Zafiro Court preliminarily noted that there is a "preference in the federal system for joint trials of defendants who are indicted together," but at the same time acknowledged that rule 14 recognizes that joinder may prejudice either a defendant or the government. Id. The Court, however, refused to interpret rule 14 as requiring severance as a matter of law when codefendants present mutually antagonistic defenses:

[P]etitioners urge us to adopt a bright-line rule, mandating severance whenever codefendants have conflicting defenses. . . . We decline to do so. Mutually antagonistic defenses are not prejudicial per se. Moreover, Rule 14 does not require severance even if prejudice is shown; rather, it leaves the tailoring of the relief to be granted, if any, to the district court's sound discretion. . . .

We believe that, when defendants properly have been joined under Rule 8(b), a district court should grant a severance under Rule 14 only if there is a serious risk that a joint trial would compromise a specific trial right of one of the defendants, or prevent the jury from making a reliable judgment about guilt or innocence. [ Id., 122 L Ed 2d 325. Emphasis added.]

The prosecutors in the instant cases urge this Court to adopt the Zafiro standard; defendants, on the other hand, rely on Hurst, supra, as mandating severance whenever codefendants have antagonistic defenses.

In arriving at the appropriate standard, it is necessary to compare the framework for the Zafiro decision, rule 14, with Michigan's counterpart, MCR 6.121(C) and (D). MCR 6.121(C) provides that "[o]n a defendant's motion, the court must sever the trial of defendants on related offenses on a showing that severance is necessary to avoid prejudice to substantial rights of the defendant." MCR 6.121(D) provides that "any party" may invoke the court's discretion to grant separate trials on the ground that it will "promote fairness to the parties and a fair determination of the guilt or innocence of one or more of the defendants." Rule 14 provides that "[i]f it appears that a defendant or the government is prejudiced by a joinder of . . . defendants . . . the court may . . . grant a severance of defendants or provide whatever other relief justice requires."

The first observation to be drawn from a comparison is that rule 14 is substantively compatible with MCR 6.121(C) and (D). MCR 6.121(C) incorporates a prejudice requirement, as does rule 14. MCR 6.121(D) and rule 14 both provide for discretionary severance. However, MCR 6.121(C) actually imposes a heightened requirement in that severance is mandated only when a defendant makes "a showing that severance is necessary to avoid prejudice to substantial rights of the defendant." A defendant must not only demonstrate that "substantial rights" have been detrimentally affected, but also that severance is "necessary," i.e., that there is no other available avenue of relief. These requirements of MCR 6.121(C) bear close resemblance to the Zafiro standard, grafted on rule 14, that severance should be granted "only if there is a serious risk that a joint trial would compromise a specific trial right . . . or prevent the jury from making a reliable judgment about guilt or innocence." Id., 122 L Ed 2d 325. Our conclusion is that while the Zafiro decision presents a newly formulated strict standard for severance as it relates to rule 14, it is comparable to the standard that already exists in Michigan.

We therefore hold that, pursuant to MCL 768.5; MSA 28.1028, and MCR 6.121(D), the decision to sever or join defendants lies within the discretion of the trial court. Severance is mandated under MCR 6.121(C) only when a defendant provides the court with a supporting affidavit, or makes an offer of proof, that clearly, affirmatively, and fully demonstrates that his substantial rights will be prejudiced and that severance is the necessary means of rectifying the potential prejudice. The failure to make this showing in the trial court, absent any significant indication on appeal that the requisite prejudice in fact occurred at trial, will preclude reversal of a joinder decision.

While we recognize that a joint trial of codefendants presenting antagonistic defenses has serious negative implications for the accused, the standard for severance is not lessened in this situation. Despite the fact that Hurst was premised on the general rule that a defendant does not have a right to a separate trial, id., p 6, we are cognizant of the fact that some lower courts have interpreted Hurst as establishing what is tantamount to a severance rule per se in antagonistic defense cases.

For instance, in People v Espinosa, 142 Mich. App. 99, 104; 369 N.W.2d 265 (1985), the Court found that even though there was no evidence of mutually antagonistic defenses and neither of the defendants testified, where each of the two defendant's attorneys wanted to argue the theory "from the confused recollections of the various witnesses" that the other defendant did the greater harm, joinder violated due process because "[t]he prosecutor's task was thereby made easier by the improper joinder." Id., p 106. On the basis of Hurst, the Espinosa Court concluded, "even where the defendants do not directly accuse one another of being the guilty party, the court should order separate trials if the proofs, combined with the defense theories, pit the defendants against each other." Id., p 104. Because each defense lawyer in a joint trial will inevitably put his client's spin on a witnesses' testimony (thereby helping the prosecutor's case), taken literally, Espinosa would always require severance. See also People v Muhammad, 170 Mich. App. 747, 759; 428 N.W.2d 762 (1988); People v Jackson, 158 Mich. App. 544; 405 N.W.2d 192 (1987).

To the extent that these cases have interpreted Hurst as authority for a severance rule per se when antagonistic defenses are alleged, we disavow such a rationale. We note that the majority of lower court decisions following in the wake of Hurst have adhered to the prejudice requirement of Schram and Carroll even where antagonistic defenses are involved. See, e.g., People v Greenberg, 176 Mich. App. 296; 439 N.W.2d 336 (1989); People v Byrd, 133 Mich. App. 767; 350 N.W.2d 802 (1984); People v Partee, 130 Mich. App. 119; 342 N.W.2d 903 (1983); People v Gibbs, 120 Mich. App. 485; 328 N.W.2d 65 (1982); People v American Medical Centers of Michigan, Ltd, 118 Mich. App. 135; 324 N.W.2d 782 (1982), cert den sub nom Fuentes v Michigan, 464 U.S. 1009 (1983); People v Larry Kramer, 108 Mich. App. 240; 310 N.W.2d 347 (1981); People v Jeffrey Kramer, 103 Mich. App. 747; 303 N.W.2d 880 (1981); People v Dunlap, 87 Mich. App. 528; 274 N.W.2d 62 (1978); People v Moore, 78 Mich. App. 294; 259 N.W.2d 351 (1977); People v Gunter, 76 Mich. App. 483; 257 N.W.2d 133 (1977).

Inconsistency of defenses is not enough to mandate severance; rather, the defenses must be "mutually exclusive" or "irreconcilable." See, e.g., United States v Arias-Villanueva, 998 F.2d 1491, 1506 (CA 9, 1993); United States v Warner, 955 F.2d 441 (CA 6, 1992); United States v Sherlock, 865 F.2d 1069 (CA 9, 1989); United States v Spitler, 800 F.2d 1267 (CA 4, 1986); United States v Vadino, 680 F.2d 1329 (CA 11, 1982); United States v Mota, 598 F.2d 995 (CA 5, 1979). Moreover, "[i]ncidental spillover prejudice, which is almost inevitable in a multi-defendant trial, does not suffice." United States v Yefsky, 994 F.2d 885, 896 (CA 1, 1993). The "tension between defenses must be so great that a jury would have to believe one defendant at the expense of the other." Id., p 897. Otherwise stated,

"It is natural that defendants accused of the same crime and tried together will attempt to escape conviction by pointing the finger at each other. Whenever this occurs the co-defendants are, to some extent, forced to defend against their co-defendant as well as the government. This situation results in the sort of compelling prejudice requiring reversal, however, only when the competing defenses are so antagonistic at their cores that both cannot be believed. Consequently, we hold that a defendant seeking severance based on antagonistic defenses must demonstrate that his or her defense is so antagonistic to the co-defendants that the defenses are mutually exclusive. Moreover, defenses are mutually exclusive within the meaning of this rule if the jury, in order to believe the core of the evidence offered on behalf of one defendant, must disbelieve the core of the evidence offered on behalf of the co-defendant." [ State v Kinkade, 140 Ariz. 91, 93; 680 P.2d 801 (1984).]

The Zafiro Court offered further insight into the nature of antagonistic defenses when it responded to the defendant's theory that, when two defendants both claim they are innocent and each accuses the other of the crime, a jury will conclude (1) that both defendants are lying and convict them both on that basis, or (2) that at least one of the two must be guilty without regard to whether the government has proved its case beyond a reasonable doubt. The Court dismissed the notion that the very nature of their defenses, without more, prejudiced them. As to the first contention, the Court responded:

[I]t is well settled that defendants are not entitled to severance merely because they may have a better chance of acquittal in separate trials. . . . While "[a]n important element of a fair trial is that a jury consider only relevant and competent evidence bearing on the issue of guilt or innocence," . . . a fair trial does not include the right to exclude relevant and competent evidence. A defendant normally would not be entitled to exclude the testimony of a former codefendant if the district court did sever their trials, and we see no reason why relevant and competent testimony would be prejudicial merely because the witness is also a codefendant. [ Zafiro, supra, 122 L Ed 2d 326.]

With regard to the second contention, the Court answered:

The Government argued that all four petitioners were guilty and offered sufficient evidence as to all four petitioners; the jury in turn found all four petitioners guilty of various offenses. Moreover, even if there were some risk of prejudice, here it is of the type that can be cured with proper instructions, and "juries are presumed to follow their instructions." Richardson [ v Marsh, 481 U.S. 200, 211; 107 S Ct 1702; 95 L Ed 2d 176 (1987)]. The District Court properly instructed the jury. . . . These instructions sufficed to cure any possibility of prejudice. [ Id., 122 L Ed 2d 326.]

The risk of prejudice may not only be allayed by proper instructions, but by the use of dual juries as well. This procedure has been successfully used in Michigan. See, e.g., People v Greenberg, supra; People v Jeffrey Kramer, supra, pp 754-755; People v Brooks, 92 Mich. App. 393, 396-397; 285 N.W.2d 307 (1979). See, generally, anno: Propriety of use of multiple juries at joint trial of multiple defendants in state criminal prosecution, 41 ALR4th 1189; anno: Propriety of use of multiple juries at joint trial of multiple defendants in federal criminal case, 72 ALR Fed 875. See also ABA Standards for Criminal Justice (2d ed), Joinder and Severance, Standard 13-3.2(c), commentary, p 13-38. The use of separate juries is a partial form of severance to be evaluated under the standard, set forth above, applicable to motions for separate trials. United States v Rowan, 518 F.2d 685, 690 (CA 6, 1975); Kramer, supra. The dual-jury procedure should be scrutinized with the same concern in mind that tempers a severance motion, i.e., whether it has prejudiced the substantial rights of the defendant. The precise issue is whether there was prejudice to substantial rights after the dual-jury system was employed.

With these stated principles in mind, we turn to the facts of the cases at hand.

III

A. PEOPLE v HANA

Before trial, both defendant and his brother Kafan moved for severance of their trials. In a supporting affidavit, defendant's counsel explained the results of a meeting that he had with Kafan's attorneys:

At said meeting affiant was advised by both counsel that the defense theory of the above case was that evidence would show, or would be consistent with a reasonable conclusion that, the controlled substances seized from 3105 Metropolitan Parkway were the property of, or possessed by, Durid Bajhat Hana and not by Kafan Hana.

Given the fact that Durid Bajhat Hana's theory of the case is that the evidence will show, or will be consistent with a reasonable conclusion that, the controlled substances seized from 3105 Metropolitan Parkway were the property of, or possessed by, Kafan Hana, and not by Durid Bajhat Hana, Durid Bajhat Hana will be compelled to act, for all practical purpose, as an assistant prosecutor as to the co-defendant, Kafan Hana, and will be unable to equitably and fairly conduct his defense absent this dichotomy of purpose.

The trial court heard argument on the motions. At the proceeding, Kafan's attorney argued:

It's our theory of defense that the cocaine in the safe belonged to Durid Hana, and I understand that it's Mr. Durid Hana's defense that the cocaine in the safe belonged to our client Kafan Hana. The two defenses could not be more antagonistic. Those were the identical facts in [the Hurst] drug case where two people are pointing the finger at each other and the case is clear that severance must be granted.

The prosecutor argued that it took more than "a mere allegation of pointing fingers at one another" to warrant separate trials. After further discussion, defendant's counsel stated:

Your Honor, if I may, I think in the interest of judicial economy, perhaps we can also add on behalf of Mr. Durid Hana, he has filed a parallel motion to sever. Mr. Hana's present intention to take the stand, I think, further buttresses the antagonistic nature of the antagonistic defenses. I think it would be very, very chilling to the equitable administration of this case for the severance to be denied. I think the [ Hurst] case is on point. I believe it's definitely a requirement, given the position of the two parties, that these cases be severed for trial.

The trial court took the matter under advisement and later denied the motion. Kafan's attorney renewed the motion for severance at trial, after the prosecution rested, and the court again denied the motion.

At trial, neither defendant nor his brother testified. However, defendant points to the following events during trial that, he alleges, created a strong inference of mutually antagonistic defenses.

In his opening statement, Kafan's attorney told jurors that their deliberations necessarily pitted brother against brother. During closing argument, defendant's attorney similarly described the defendant's relative postures as "brother pitted against brother." The closing argument of Kafan's attorney included an attack on the theory that his client had control over the three kilograms of cocaine seized from the safe:

We know he used the Cadillac, we know he used the house, we know he used the safe, but we know he didn't own the Cadillac and own the house and own the safe. . . . Everybody who has ever shared a locker in school or anybody who's ever shared an apartment, everybody who's ever lived in a rooming house and had to share a bathroom knows that you can share special areas and have absolutely no right to control something that belongs to somebody else. . . .

The prosecutor pointed out the conflict during rebuttal closing argument when she noted: "That's real convenient for these two boys to sit here and say that the drugs belonged to one another." This remark was stricken. The prosecutor later stated:

The position that Durid Hana and Kevin [sic] Hana had taken in this trial is saying that the drugs did not belong to them, but they were in their bedroom and they were in a safe that they both had access to, and if you believe both Durid Hana and Kevin Hana, the good fairy must have delivered the drugs and locked them in the safe. It's not reasonable to believe that they did not know that they were there. Someone had put those drugs in that safe, and if you look at all of the evidence that occurred that night, it is reasonable to believe that both of them knew it.

Defendant argues that it is not dispositive that neither he nor Kafan actually testified against one another because the evidence pitted them against one another; in order for one to be acquitted, the jury had to find that the narcotics belonged exclusively to the other.

Our conclusion, however, is to the contrary. The affidavit submitted by defendant in support of his motion for severance was conclusory in nature. It lacked sufficient specificity to enable the trial court to accurately determine what the defenses would be, how the defenses would affect each other, and whether the defendants' respective positions were indeed mutually exclusive or merely inconsistent. Potentially prejudicial evidence, either physical or testimonial, was not substantiated by the affidavit or at the hearing. A trial court ruling on a pretrial motion must have concrete facts on which to base a ruling; mere finger pointing does not suffice. In the absence of proof that clearly, affirmatively, and fully demonstrated that defendant's substantial rights were prejudiced and that severance was necessary, we will not interfere with the trial court's discretion.

With the benefit of hindsight, we further find that defendant was not irretrievably prejudiced at trial. Neither defendant testified, so there were no express cross-accusations. Indeed, apart from the noted comments of respective counsel in their opening statements and summations, there was nothing inherently antagonistic in the evidence adduced at trial. The most obvious points of conflict were the statements made by defendant and his brother to the police that were admitted at trial. Defendant's statement, written into the officer's report, was as follows:

"Mr. Hana, after being advised of his rights, when asked about the safe that was found in his bedroom, stated that the safe belonged to him and that he knew the combination of it. He stated he kept his mother's jewelry, some personal papers and blank checks in the safe. He denied knowing there were three kilos of suspected cocaine in the safe. He said he shares the bedroom with his brother but he had no idea what his brother was doing."

Police testimony established that Kafan made statements indicating that there were three kilograms of cocaine in the safe and that he (Kafan) was "a dead man." Kafan never made a statement or even inferred that the drugs did not belong to him or were the sole property of his brother. Consequently, the defenses did not rise to the level of mutual or irreconcilable antagonism. We further note that virtually all the state's evidence was admissible against both defendants. Finally, for reasons already recognized in our discussion of Espinosa, supra, the attorneys' verbal tug of war did not transform the proceedings into an unfair trial for the defendant. With the cautionary instructions that were given by the trial court concerning reasonable doubt and the determination of guilt or innocence on an individual basis, the jury could reasonably be expected to compartmentalize the evidence pertaining to each defendant.

We therefore affirm the decision of the Court of Appeals denying defendant's motion for a separate trial.

B. PEOPLE v RODE AND PEOPLE v GALLINA

Defendants Rode and Gallina each submitted pretrial motions for separate trials, asserting that antagonistic defenses would be presented during trial. In response to the motions, the trial court ordered that separate juries would be impaneled to hear the cases against the two codefendants.

When the trial commenced, separate juries were selected from the same venire. Voir dire was conducted in the presence of potential jurors for both defendants, over defense objection. Before the presentation of any evidence, the prosecutor moved to amend his witness list to endorse each defendant as a witness against the other. The prosecutor indicated, on the record, his realization that he could not call the codefendants in his case in chief because they could exercise their Fifth Amendment rights not to testify. The prosecutor stated that if either defendant chose to testify in his own behalf, he wished to reopen his proofs so that one defendant's testimony could be presented in front of the codefendant's jury. The court ruled that the prosecutor's motion would be granted if the defendants chose to testify.

The attorneys presented separate opening arguments to the respective juries. Near the close of the state's case, the prosecutor asked on the record, outside the presence of both juries, whether each codefendant would exercise his Fifth Amendment rights if called by the prosecution as a witness before the other's jury. Both defense attorneys indicated that their clients would refuse to testify if called during the prosecution's case in chief.

After the prosecution rested, defendant Rode presented his case. Defendant Gallina's jury was removed during the presentation of defendant's defense, until defendant Rode himself was called to testify. At that point, the prosecutor again raised his request to reopen his proofs to call defendant Rode as a witness against defendant Gallina. Once the court determined that defendant Rode was indeed going to give substantive testimony, he granted the prosecution's request. The trial court ruled that defendant Rode's testimony would be presented only one time, before both juries, with defendant Rode's counsel conducting the direct examination and the prosecutor and defendant Gallina's counsel doing cross-examination. The testimony proceeded accordingly, with defendant Rode denying that he fired any shots at the Mustang and asserting that defendant Gallina fired the fatal shots. Later in the trial, the testimony of defendant Gallina, inculpating defendant Rode, was presented in front of both juries under the same procedure.

During the prosecution's case, a police officer testified, relating a statement given by defendant Gallina that was consistent with Gallina's live testimony. This statement was read only in the presence of the Gallina jury.

Both juries heard cross-examination of the decedent's brother by defendant Rode's attorney that on the night of the shooting he told the police that the front seat passenger shot his brother. This testimony was presented over defense objection and a request by defendant Rode's attorney at a side-bar conference that the Gallina jury be removed before he began this line of cross-examination. The testimony was elicited by defendant Rode as part of his defense theory that defendant Gallina (the front seat passenger) was the only guilty party.

Defendants now maintain that had separate trials been granted, the juries would not have heard the voir dire concerning the inconsistent theories, the cross-examination of each witness (particularly the decedent's brother) by the codefendant's counsel and the testimony of each codefendant. Defendants maintain that sufficient procedural safeguards were not implemented to effectively protect each jury from hearing the antagonistic defense of the codefendant. Consequently, the juries knew that only one defendant had fired the fatal shot and that each defendant claimed the other had done it. Each defendant therefore had to convince his jury not only that he did not fire the fatal shot, but that the other defendant did and was not to be believed.

In evaluating the alleged prejudice incurred by defendants Gallina and Rode through the use of separate juries, the question presented in this situation must be identified precisely. As noted above, the dual-jury procedure is a partial form of severance, to be evaluated under the standard applicable to motions for separate trials. The issue is whether there was prejudice to substantial rights after the dual-jury system was employed.

In his dissenting opinion, Justice LEVIN frames the inquiry as whether dual juries afforded the same protection to the defendants' rights as there would have been through separate trials. Post at 383. This inquiry, so stated, begs the question what that protection is. In response, we reiterate that, stated in practical terms, severance should be granted "only if there is a serious risk that a joint trial would compromise a specific trial right of one of the defendants, or prevent the jury from making a reliable judgment about guilt or innocence." Zafiro, supra, 122 L Ed 2d 325. See text, supra, p 346 and n 7. Otherwise stated, "the defendant `must show that the magnitude of the prejudice denied him a fair trial.' . . . [R]eversible prejudice exists when one of the defendant's `substantive rights,' such as the `opportunity to present an individual defense,' is violated." United States v Tootick, 952 F.2d 1078, 1082 (CA 9, 1991) (citations omitted).

In the instant case, the defendants, and the dissent, fail to demonstrate what trial rights were violated by the dual-jury procedure or how the juries' determinations were unreliable. There is no indication that either defendant was restricted in his presentation of a defense, nor was either jury exposed to evidence that would have been barred from their considerations in separate trials.

The presence of two juries in the defendants' cases is significant. Where mutually antagonistic defenses are presented in a joint trial, there is a heightened potential that a single jury may convict one defendant, despite the absence of proof beyond a reasonable doubt, in order to rationalize the acquittal of another. That dilemma is not presented to dual juries. Each jury is concerned only with the culpability of one defendant; thus, they both can find the defendants innocent or guilty without the uneasiness of inconsistency that would be presented to a single jury in a joint trial. The chance for prejudice is therefore significantly lessened.

The risk of prejudice is reduced even more in these cases by the significant fact that the prosecutor charged defendant Gallina as an aider and abettor, MCL 767.39; MSA 28.979, and did not contend that he fired the fatal shot. Finger pointing by the defendants when such a prosecution theory is pursued does not create mutually exclusive antagonistic defenses. The properly instructed jury could have found both defendants similarly liable without any prejudice or inconsistency because one found guilty of aiding and abetting can also be held liable as a principal.

Moreover, even as the defendants recognize, when each defendant testified before his own jury, he thereby waived his Fifth Amendment rights regarding the events in question. Thereafter, it became permissible for the prosecution to call that defendant as a witness in the trial of the codefendant. As the Zafiro Court noted, "[a] defendant normally would not be entitled to exclude the testimony of a former codefendant if the district court did sever their trials, and we see no reason why relevant and competent testimony would be prejudicial merely because the witness is also a codefendant." Zafiro, supra, 122 L Ed 2d 326.

The defendants argue that had the trial court elected to order separate trials rather than separate juries, the jury of the defendant who was tried first would presumably not have heard any testimony from the codefendant, because the codefendant would most likely have exercised his Fifth Amendment right pending his own trial.

However, this Court cannot employ "what if" speculation as the basis for a severance rule. Were we to do so, prejudice could always be imagined, and the option of severance would be virtually foreclosed.

Similarly, the theories set forth in the dissenting opinion regarding what the prosecutor would have introduced or not introduced at a separate trial is pure speculation. The dissent focuses exclusively on the cross-examination of prosecution witnesses by codefendants' counsel as the prejudicial events, theorizing that impeachment evidence introduced by defense counsel probably would not have been introduced for consideration by the respective juries if there had been separate trials. However, "a fair trial does not include the right to exclude relevant and competent evidence." Zafiro, 122 L Ed 2d 326. All of the evidence and testimony admitted at the dual trial would have been available for use at either of the defendants' separate trials. It is not dispositive that the evidence was presented here by counsel for a codefendant, rather than the prosecutor. None of the evidence was "probative of a defendant's guilt but technically admissible only against a codefendant," Zafiro, 122 L Ed 2d 325, as a possible basis for severance. Nor were the defendants barred from presenting "essentially exculpatory evidence that would be available to a defendant tried alone, but unavailable in a joint trial." Id.

Finally, the trial court's decision to utilize a single jury venire did not substantially prejudice the defendants. The questions pursued by both defendants' counsel during this procedure neither expressly nor implicitly addressed the topic of the alleged conflicting defenses that would be presented at trial.

In conclusion, although we certainly recognize the potential for confusion in the dual-jury procedure, we do not find such circumstances in the instant cases. The defendants were given every opportunity to present complete defenses before their respective juries, and they have failed to demonstrate how the juries' abilities to render fair decisions were adversely affected. The dual-jury procedure had the advantage of presenting the state's case, which was equally admissible against both defendants, in one setting, with all witnesses testifying at only a single proceeding. The appropriate cautionary instructions were given, with the reasonable presumption that the juries followed these instructions to consider the evidence against each defendant separately.

In the absence of demonstrated prejudice to the defendants' substantial rights, we hold that the trial court did not abuse its discretion in conducting a joint trial with separate juries under these circumstances.

The decision of the Court of Appeals is therefore reversed.

BRICKLEY, BOYLE, RILEY, and MALLETT, JJ., concurred with GRIFFIN, J.