Federal Motion to Sever Defendants or Counts

What a Motion to Sever Does

A federal criminal case often charges several defendants, several offenses, or both in a single indictment. A motion to sever asks the trial judge to break that combined case apart, so that a defendant is tried by himself or so that groups of counts are heard in separate proceedings. The motion does not attack the sufficiency of the charges; it attacks the fairness of trying them all together in one courtroom, before one jury.

Federal law approaches the question in two distinct steps, and it helps to keep them apart:

• Was joinder even proper? This is a question of law under Rule 8. If the offenses or defendants do not meet the rule's joinder criteria, they were misjoined from the outset.
• Even if joinder was proper, is it prejudicial? This is a discretionary question under Rule 14. A judge may order separate trials when an otherwise lawful joinder would still unfairly harm a defendant or distort the jury's judgment.

The distinction matters because the two theories carry different standards and different consequences. Misjoinder under Rule 8 is measured by what the indictment alleges on its face, while Rule 14 prejudice is measured against the evidence and the realities of the trial itself. A careful motion usually raises both grounds in the alternative, so the court sees the complete picture before it decides whether one trial or several is the fair way to proceed.

Severing Defendants vs. Severing Counts

The word "severance" answers two different questions, depending on what the government has combined in the indictment.

Severance of counts

Under Rule 8(a), a single defendant's offenses may be charged together when they are of the same or similar character, are based on the same act or transaction, or are connected in a common scheme or plan. A motion to sever counts asks the court to try one group of charges apart from another.

Severance of defendants

Under Rule 8(b), two or more defendants may be charged together when they are alleged to have participated in the same act or transaction, or in the same series of acts or transactions. A motion to sever defendants asks the court to give one defendant a trial separate from the co-defendants.

The two settings raise different dangers. Joining counts can invite propensity reasoning, the risk that jurors will treat evidence on one charge as proof of a criminal disposition on another, or will simply pool weak proof across counts to reach a verdict. Joining defendants creates spillover and guilt-by-association risks, where strong evidence against one participant colors the jury's view of a less-involved co-defendant. Identifying which kind of severance a case needs is the first practical step, because the governing case law is largely organized around that divide.

Misjoinder Under Rule 8

The threshold question is whether the indictment satisfies Rule 8 at all. Because misjoinder is a defect in how the case was charged, courts generally evaluate it from the face of the indictment, asking whether the pleading alleges the connection the rule requires rather than whether the government later proves it at trial.

When several defendants are joined, Rule 8(b) requires that they be alleged to have taken part in the same act or transaction, or the same series of acts or transactions. Merely committing similar crimes is not enough to join separate defendants; there must be a logical relationship linking them in a shared enterprise. Improperly combining unrelated defendants, or two distinct conspiracies, into a single indictment is a classic misjoinder theory.

Two features shape how this argument is used:

• It is not discretionary. If the indictment fails Rule 8's requirements, joinder was improper as a matter of law, and the judge does not weigh convenience or prejudice at this stage.
• It is not automatically reversible. On appeal, a misjoinder generally will not undo a conviction unless it actually affected the defendant's substantial rights. That harmless-error overlay is a major reason defense counsel almost always pairs a Rule 8 argument with a Rule 14 prejudice showing.

In practice, misjoinder motions are strongest in sprawling multi-defendant indictments where the government has stitched together loosely related actors, and weakest where a single conspiracy count genuinely ties every defendant to one shared objective.

The Zafiro Standard and the Preference for Joint Trials

When joinder is proper, Rule 14 governs, and the controlling decision is Zafiro v. United States, 506 U.S. 534 (1993). The Supreme Court set a demanding standard: a district court should grant a severance "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."

Several features of Zafiro make severance difficult to win:

• Rule 14 does not require severance even when prejudice is shown; it leaves the choice of remedy to the trial court's sound discretion.
• A defendant is not entitled to severance merely because he might have a better chance of acquittal in a separate trial.
• Less drastic measures, especially limiting instructions, will often cure whatever risk exists, because juries are presumed to follow the court's instructions.

That standard reflects a strong federal policy favoring joint trials. The Supreme Court has emphasized that joint trials conserve judicial resources, spare witnesses and victims from testifying more than once, avoid the inequity of inconsistent verdicts, and let the jury assess relative culpability accurately. Because a substantial share of federal criminal trials have historically been joint trials, the system treats a single proceeding as the norm and severance as the exception. The practical lesson is that a movant must identify a concrete, specific prejudice, not a general preference for standing trial alone.

The Bruton Problem and Its Limits

The most common trigger for severing defendants is a co-defendant's confession. In Bruton v. United States, 391 U.S. 123 (1968), the Supreme Court held that admitting a nontestifying co-defendant's confession that names the defendant violates the Confrontation Clause, even when the judge instructs the jury to consider the statement only against the person who made it. Because the confessing co-defendant cannot be cross-examined, the "powerfully incriminating" accusation is one a limiting instruction cannot reliably cure.

Later decisions drew the boundaries of that rule around whether the statement is incriminating on its face:

The through-line is that Bruton reaches only confessions that incriminate the defendant on their face. A statement that becomes incriminating only when the jury links it to other evidence falls outside the rule, as Richardson held, and a genuinely neutral rewrite survives, as Samia recently confirmed. When the government can neutralize a confession through effective redaction plus a limiting instruction, a court is far more likely to admit the edited statement than to order separate trials.

Antagonistic Defenses and Spillover Prejudice

Beyond confessions, defendants most often seek severance on two grounds: conflicting defenses and evidentiary spillover.

Mutually antagonistic defenses. Co-defendants sometimes intend to blame one another, so that the jury's acceptance of one defense implies the other's guilt. Zafiro squarely held that mutually antagonistic defenses are not prejudicial per se and do not require severance as a matter of law. A defendant must show that the conflict would actually deprive him of a fair trial, for example by preventing the jury from weighing the evidence reliably, and not merely that finger-pointing will occur between the defense tables.

Spillover prejudice. In a multi-count or multi-defendant trial, jurors hear evidence that would never be admitted against a particular defendant tried alone. The worry is that damaging proof about one participant, or about one count, will "spill over" and taint the jury's judgment on the rest of the case. Courts, however, regularly conclude that jurors can compartmentalize the evidence, especially when the judge gives careful limiting instructions and the government presents its proof defendant-by-defendant or count-by-count.

Because of Zafiro's deference to the trial court, these arguments succeed only with a specific, well-documented showing. Generalized claims, that the evidence against a co-defendant is stronger, or that a joint trial is simply riskier, almost never carry the day. Effective motions tie the claimed prejudice to an identifiable trial right, or to a concrete reason the jury could not follow instructions on the particular facts.

When and How the Motion Is Filed

Timing is governed by Rule 12. A motion alleging a defect in joining offenses or defendants, including both misjoinder under Rule 8 and a request for Rule 14 relief, must ordinarily be raised before trial, within the deadline the district court sets. Failing to file on time can forfeit the issue absent a showing of good cause.

Two timing practices are worth knowing:

• Renewal at trial. Because Rule 14 prejudice depends on how the evidence actually unfolds, courts often expect a defendant to renew the severance request as the proof comes in and again at the close of evidence. Renewal keeps the issue alive and gives the judge a concrete record to evaluate.
• In camera review of confessions. Rule 14(b) allows the court to order the government to produce a co-defendant's statement for the judge's private inspection, so the court can decide whether redaction will solve a Bruton problem or whether a separate trial is necessary.

A persuasive motion is specific. Rather than asserting general unfairness, it identifies the exact confession, the antagonistic defense, or the category of evidence at issue; explains why a limiting instruction or redaction cannot cure it; and proposes the narrowest workable remedy. Supporting the motion with the indictment, the relevant discovery, and, where useful, a proposed redaction gives the court what it needs to rule.

Remedies, Review, and Where This Motion Fits

The range of remedies. Severance is not all-or-nothing. A judge weighing a Rule 14 motion can order fully separate trials, but may instead sever only certain counts or certain defendants, admit a redacted confession, deliver a targeted limiting instruction, or exclude a specific piece of evidence. Courts favor the least drastic option that protects the defendant's rights, which is why redaction and instructions so frequently substitute for separate trials.

Standard of review. A trial court's ruling on severance is reviewed only for abuse of discretion, and a defendant challenging a denial on appeal generally must show clear, specific, and compelling prejudice that resulted in an unfair trial. That deferential standard, reinforced by Zafiro, is why the severance question is usually won or lost in the district court rather than on appeal.

Where it fits. A motion to sever is one of the pretrial motions raised under Rule 12, alongside motions to suppress, motions to dismiss the indictment, and motions for a bill of particulars. In the Fifth Circuit, which covers the federal courts in Texas, severance practice follows these Supreme Court standards, and the court of appeals and each district court's local rules and scheduling order fix the filing deadlines. Because the analysis is fact-intensive and the stakes are high, defendants facing a joint federal indictment benefit from evaluating severance early, while there is still time to shape the record the judge will use.

L and L Law Group, PLLC represents clients in federal criminal cases in the Northern and Eastern Districts of Texas. To discuss whether a severance motion fits a particular situation, call (972) 370-5060 or email info@landllawgroup.com. This article is general legal information, not legal advice.

Common Situations & Variations

This motion comes up in several recurring situations. Each guide below walks through a specific fact pattern, the governing standard, and how Federal courts have handled it.

What the Case Law Says

These decisions—verified against primary sources—control how this motion is litigated. Every case still turns on its own facts.

• Zafiro v. United States, 506 U.S. 534 (1993) — A court should sever under Rule 14 only when a joint trial poses a serious risk to a specific trial right or a reliable verdict.
• Bruton v. United States, 391 U.S. 123 (1968) — Admitting a nontestifying codefendant's confession that names the defendant violates the Confrontation Clause, even with a limiting instruction.
• Richardson v. Marsh, 481 U.S. 200 (1987) — A codefendant's confession redacted to remove any reference to the defendant's existence, plus a limiting instruction, does not violate the Confrontation Clause.
• Gray v. Maryland, 523 U.S. 185 (1998) — Redacting a confession with an obvious blank or the word 'deleted' still violates Bruton because it remains directly accusatory.
• Samia v. United States, 599 U.S. 635 (2023) — A codefendant's confession using a neutral placeholder instead of the defendant's name, with a limiting instruction, does not violate the Confrontation Clause.

General summaries of published opinions for information only — not predictions about any specific case.