Mistrials in Massachusetts Criminal Cases

When a Massachusetts judge declares a mistrial, the current criminal trial ends without a final verdict on every unresolved charge. The judge discharges the jury, but the mistrial does not decide whether the defendant is guilty or not guilty on those charges. The unresolved charges remain pending unless double jeopardy prohibits another trial, and the Commonwealth may seek to try them before a new jury. Any verdict already returned in open court and recorded on a separate charge remains effective.

Whether a second trial is permitted depends principally on how and why the first trial ended. If the defendant requested or consented to the mistrial, the Commonwealth ordinarily may retry the case. If the defendant objected, double jeopardy bars a retrial unless manifest necessity justified ending the first trial. If a prosecutor deliberately provoked the defendant into requesting a mistrial, double jeopardy may bar a second trial even though the defense made the request.

A deadlocked jury is the most common example of manifest necessity. Prejudicial evidence, improper argument, outside influence on the jury, or the loss of a juror may also lead to a mistrial, but the judge must first consider whether a narrower response can allow the trial to continue.

This page explains how Massachusetts courts decide those questions, how counsel preserves an objection, how judges handle deadlocked juries and partial verdicts, and how the defense challenges a proposed retrial. The related objections, curative instructions, and preservation requirements appear in the firm’s guide to trial motion practice in Massachusetts criminal cases. The firm’s broader trial materials are collected under Massachusetts criminal court practice.

When Jeopardy Attaches

In a jury trial, jeopardy attaches when the jury is sworn. In a bench trial, it attaches when the court begins to hear evidence. From that point, the defendant has a protected interest in having the case completed by the judge or jury selected to decide it. Wade v. Hunter, 336 U.S. 684, 689 (1949); Commonwealth v. DeFuria, 400 Mass. 485, 487 (1987).

The general rules of double jeopardy, including the same-offense test, retrial after an appeal, and successive state and federal prosecutions, are set out on the firm’s page on double jeopardy in Massachusetts. This page is limited to the rules that govern ending a trial without a verdict.

That protection does not prohibit every retrial after a mistrial. It controls the circumstances under which the judge may end the first trial and permit the Commonwealth to begin again.

When the defendant requests or consents to the mistrial, a retrial ordinarily does not violate double jeopardy. When the defendant objects, the Commonwealth must establish that manifest necessity justified ending the trial without a verdict.

Requests, Consent, and Objections

Only the judge declares a mistrial. The defendant or the Commonwealth may request one, and either party may state a position when the judge raises the subject on the court’s own motion.

A Mistrial Requested by the Defendant

A defendant who successfully requests a mistrial ordinarily may be tried again. By requesting that the trial end, the defendant generally gives up the right to insist that the original jury complete the case. Oregon v. Kennedy, 456 U.S. 667, 679 (1982); Mercedes v. Commonwealth, 405 Mass. 693, 696 (1989); Commonwealth v. Babb, 389 Mass. 275, 282 (1983).

The rule applies even when serious error prompted the motion. A mistrial corrects the prejudice by ending the trial before a verdict. Unless an exception applies, the Commonwealth retains the authority to begin a second trial before a different jury.

A Mistrial Declared Over the Defendant’s Objection

When the judge declares a mistrial over the defendant’s timely objection, the Commonwealth may retry the unresolved charges only if manifest necessity justified ending the first trial.

The same rule applies whether the judge acted on the court’s own motion or granted a request from the Commonwealth. A prosecutor’s request does not itself establish manifest necessity. The judge must examine the circumstances, hear the parties’ positions, and consider reasonable alternatives to ending the trial.

The Commonwealth bears a heavy burden of supporting the mistrial when the defendant objected. Commonwealth v. Phetsaya, 40 Mass. App. Ct. 293, 297 (1996). The objection preserves the double jeopardy claim, but it does not establish that a second trial is barred.

Express and Implied Consent

A defendant may consent expressly by agreeing to the mistrial. A court may also infer consent when defense counsel had a meaningful opportunity to object and remained silent. Commonwealth v. Edwards, 491 Mass. 1, 13 (2022).

In Pellegrine v. Commonwealth, 446 Mass. 1004, 1005 (2006), counsel remained silent despite an adequate opportunity to object, and the Supreme Judicial Court held that consent could be inferred from that silence.

Silence does not establish consent when the defendant had no meaningful opportunity to object or the record otherwise shows that the defense wanted the trial to continue. Edwards, 491 Mass. at 15 to 16.

The defense must also respond to the mistrial the judge is proposing at that time. An earlier defense motion for a mistrial does not establish consent to a later mistrial based on a different event. It also does not preserve an objection to the later decision. Jones v. Commonwealth, 379 Mass. 607, 621 (1980).

If the defense wants the trial to continue, counsel should object on the record when the judge proposes the mistrial and identify the available alternatives.

Misconduct Intended to Provoke a Defense Motion

A narrow exception applies when a prosecutor intended to provoke the defendant into requesting a mistrial. If the prosecution deliberately created the problem to force the defense to end the trial, double jeopardy may prohibit a second prosecution even though the defendant requested the mistrial. Oregon v. Kennedy, 456 U.S. 667, 679 (1982); Commonwealth v. Andrews, 403 Mass. 441, 447 to 448 (1988).

The controlling question is intent. A serious mistake, an improper question, or a discovery violation does not by itself establish that the prosecutor intended to terminate the trial. Commonwealth v. Lam Hue To, 391 Mass. 301, 312 to 314 (1984).

What Manifest Necessity Requires

The manifest-necessity standard comes from United States v. Perez, 22 U.S. (9 Wheat.) 579, 580 (1824). The Supreme Court held that a judge may discharge a jury without a verdict when manifest necessity requires it or when continuing the trial would defeat the ends of public justice. Massachusetts applies the same standard. Commonwealth v. Cassidy, 410 Mass. 174, 177 (1991).

Manifest necessity requires a high degree of necessity, but it does not require literal or absolute necessity. Arizona v. Washington, 434 U.S. 497, 505 to 506 (1978). The judge must make an honest inquiry into the circumstances and determine whether a practical alternative would permit the trial to continue.

The record should ordinarily show that the judge:

• Identified the event that might require a mistrial.
• Gave counsel a meaningful opportunity to state their positions.
• Considered reasonable alternatives presented by the circumstances.
• Determined why those alternatives would not adequately protect the parties or the integrity of the trial.

The judge need not discuss every conceivable alternative. The question is whether the judge carefully considered the realistic alternatives before terminating the trial. Commonwealth v. Steward, 396 Mass. 76, 78 to 79 (1985); Read v. Commonwealth, 495 Mass. 312, 325 to 326 (2025).

In Steward, the Supreme Judicial Court barred a retrial because the judge ended the trial after three jurors failed to appear without adequately considering alternatives proposed by counsel. The decision illustrates why the available alternatives must be developed on the record before the jury is discharged.

The trial judge has discretion to decide whether the circumstances require a mistrial. A reviewing court examines that determination for abuse of discretion, taking account of the reason for the mistrial, the inquiry the judge conducted, counsel’s positions, and the alternatives available at the time. Commonwealth v. Cohen, 412 Mass. 375, 383 (1992); Commonwealth v. Cunneen, 389 Mass. 216, 223 to 224 (1983).

A Deadlocked Jury

A genuinely deadlocked jury is the prototypical example of manifest necessity. When jurors cannot reach a unanimous verdict after sufficient deliberation, the judge may discharge them and the Commonwealth ordinarily may retry the unresolved charges. Commonwealth v. Ellis, 432 Mass. 746, 751 (2000); Commonwealth v. Andrews, 403 Mass. 441, 448 to 449 (1988). Jeopardy does not terminate merely because the jury could not agree. Richardson v. United States, 468 U.S. 317, 326 (1984).

A judge who receives a report of deadlock may give the supplemental instruction derived from Commonwealth v. Tuey, 8 Cush. 1 (1851), and revised in Commonwealth v. Rodriquez, 364 Mass. 87, 101 to 102 (1973). The instruction directs jurors to reconsider their views in light of the other jurors’ positions. It also tells each juror not to surrender an honest conviction merely to reach a verdict.

General Laws c. 234A, § 68C limits repeated deliberations. If a jury returns without a verdict after due and thorough deliberation, the judge may explain the law or evidence again and direct further deliberations. If the jury returns a second time without a verdict, the judge may not send the jurors out again unless they consent or ask for further explanation of the law. Commonwealth v. Tiscione, 482 Mass. 485, 492 (2019).

The second qualifying report does not automatically require a mistrial. The judge may ask whether the jurors consent to continue or need additional legal instruction. If neither condition exists and the jury remains unable to agree, the judge may declare a mistrial. That was the sequence in the Lindsay Clancy trial in Plymouth Superior Court, where the defense was lack of criminal responsibility.

A disagreement among jurors also does not authorize the judge to remove the juror who remains unpersuaded. Removal requires a separate finding that the juror cannot continue to perform the duties of a juror. The firm’s analysis of the Lindsay Clancy jury dispute and removal of a deliberating juror explains that distinction.

Improper Evidence or Argument

When the jury hears inadmissible evidence or improper argument, the judge ordinarily begins with a narrower response. The judge may sustain an objection, strike testimony, limit further questioning, or instruct the jury to disregard what it heard. A mistrial becomes appropriate when those measures cannot adequately remove the prejudice.

Evidence the Jury Should Not Have Heard

Jurors ordinarily are presumed to follow a judge’s clear instruction to disregard stricken testimony. Commonwealth v. Auclair, 444 Mass. 348 (2005); Commonwealth v. Cameron, 385 Mass. 660, 668 (1982).

The trial judge decides whether an instruction can cure the error or whether the evidence has created prejudice that requires a mistrial. Commonwealth v. Kilburn, 426 Mass. 31, 37 to 38 (1997); Commonwealth v. Gallagher, 408 Mass. 510, 517 (1990).

The party requesting a mistrial must identify the improper evidence and explain why striking it or instructing the jury will not cure the resulting prejudice. That question often arises when testimony reveals a prior criminal record, a suppressed statement, or another accusation that the jury should not consider. The particular words, the context, the strength of the other evidence, and the judge’s response all affect the ruling.

Improper Argument

Improper argument does not automatically require a mistrial. The judge considers the challenged language in the context of the entire argument, the evidence, the issues the jury must decide, and any instruction given in response. Courts assess the combined effect of multiple errors rather than treating each sentence in isolation. Commonwealth v. Borodine, 371 Mass. 1, 11 (1976).

A prosecutor may not comment, directly or indirectly, on a defendant’s decision not to testify. Commonwealth v. Gouveia, 371 Mass. 566, 571 (1976). When improper argument creates prejudice that an instruction cannot cure, the judge may declare a mistrial.

Counsel must ordinarily object when the improper statement is made, identify the ground, and request the appropriate response. The governing argument and preservation rules appear on the page covering opening statements and closing arguments in Massachusetts criminal trials.

Extraneous Influence on the Jury

A judge must investigate when credible information raises a serious question that a juror encountered material outside the evidence or received improper contact from someone outside the courtroom. Commonwealth v. Jackson, 376 Mass. 790, 800 to 801 (1978); Commonwealth v. Tennison, 440 Mass. 553, 557 to 558 (2003).

The court ordinarily questions the affected jurors individually. The judge may ask what the juror encountered, where it came from, whether the juror communicated it to anyone else, and whether the juror can remain impartial.

The inquiry cannot examine the substance of deliberations. A judge may not ask how a juror evaluated the evidence, why the juror voted a particular way, or what effect the outside information had on the juror’s reasoning.

The judge may respond by instructing the jury, removing a juror for a legally sufficient reason, or taking another measure that protects the trial. A mistrial is appropriate when the court cannot remove the prejudice through those alternatives. Commonwealth v. Trapp, 423 Mass. 356, 362 (1996); Commonwealth v. Kamara, 422 Mass. 614, 620 (1996).

Loss or Disqualification of a Juror

The available response to the loss of a juror depends on whether deliberations have begun.

Before deliberations, an available alternate ordinarily replaces a juror who becomes ill, encounters an emergency, or is found unable to serve.

After deliberations begin, G.L. c. 234A, § 39 permits the judge to discharge a deliberating juror only after a hearing establishes an emergency or another compelling reason. The reason ordinarily must be personal to the juror and unrelated to the juror’s view of the evidence, position on the verdict, or relationship with the other jurors. Commonwealth v. Tiscione, 482 Mass. 485, 489 to 493 (2019).

If the judge properly discharges a deliberating juror and an alternate remains available, Mass. R. Crim. P. 20(d)(3) permits substitution. The reconstituted jury must renew its deliberations. The judge must instruct the jurors to set aside the earlier deliberations and begin again with the alternate participating. Commonwealth v. Carnes, 457 Mass. 812, 829 to 831 (2010).

A mistrial is not necessarily required when no alternate remains. Under Mass. R. Crim. P. 19(b), a defendant may waive the right to a full jury. The judge must conduct an on-record colloquy, determine that the waiver is knowing and voluntary, and obtain a signed written waiver for filing with the court. When there are multiple defendants, each defendant must waive the right unless the judge severs the cases.

A judge considering a mistrial over the defendant’s objection must consider proceeding with the remaining jurors when the defendant offers a valid waiver and that alternative is legally and practically available. Commonwealth v. Nicoll, 452 Mass. 816 (2008).

The broader rules governing jurors and alternates appear on the firm’s page about jury selection in Massachusetts criminal trials.

Partial Verdicts and When a Verdict Becomes Final

When a jury reaches agreement on some separate charges but remains deadlocked on others, Mass. R. Crim. P. 27(b) permits the judge to accept and record the verdicts on the charges the jury has resolved. The jury may then continue deliberating on the remaining charges, or the judge may declare a mistrial as to those charges.

The judge has discretion to decide whether to ask about or accept partial verdicts on separate charges. The judge is not required to initiate that inquiry before declaring a mistrial. Daniels v. Commonwealth, 441 Mass. 1017, 1018 n.3 (2004); Read v. Commonwealth, 495 Mass. 312, 321 to 326 (2025).

A different rule applies to a greater offense and its lesser included offenses within a single complaint or count. The judge may not ask whether the jury has reached a partial verdict on one of those alternatives. A greater offense and its lesser included offenses constitute one charge for this purpose, and an inquiry may pressure jurors to convert a tentative position into a verdict. Commonwealth v. Roth, 437 Mass. 777, 787 to 793 (2002).

The distinction is therefore between separate charges and alternative verdicts within one charge:

• The judge may accept a verdict on one separate complaint, indictment, or count while the jury continues to deliberate on another.
• The judge may not ask for a partial verdict on a greater or lesser included offense within one unresolved complaint or count.

A verdict does not become effective merely because jurors privately agreed on it. The jury must return the verdict in open court, affirm it as the unanimous verdict, and permit the court to record it. A Juvenile v. Commonwealth, 392 Mass. 52, 56 to 57 (1984); Read v. Commonwealth, 495 Mass. 312, 327 to 329 (2025).

Statements made by jurors after their discharge cannot convert an unannounced private agreement into an acquittal or a conviction. Courts permit juror inquiries only in narrow circumstances, including extraneous influence, racial or ethnic bias, and a clerical mistake in recording a verdict already announced in court. Those exceptions do not permit an inquiry into an unannounced vote or the reasoning used during deliberations.

If the court accepted and recorded a not-guilty verdict on a separate charge, double jeopardy bars the Commonwealth from retrying that charge even if the trial ended in a mistrial on the others.

Challenging a Mistrial and Proposed Retrial

Counsel should preserve a double jeopardy claim before the judge discharges the jury. The defense should object clearly, ask to be heard, identify the alternatives that would allow the trial to continue, and request findings sufficient to explain the judge’s decision.

After the mistrial, the defendant may move to dismiss the unresolved complaint or indictment on double jeopardy grounds. The motion should identify whether the defendant objected, why manifest necessity was absent, and which reasonable alternatives the judge failed to consider.

If the trial court denies the motion and the double jeopardy claim has substantial merit, the defendant may petition a single justice of the Supreme Judicial Court under G.L. c. 211, § 3 and request a stay before the second trial begins. Neverson v. Commonwealth, 406 Mass. 174, 175 (1989); Choy v. Commonwealth, 456 Mass. 146, 147 (2010).

The standard for that petition, and the pleas of former acquittal and former conviction that raise the bar in other settings, are set out on the double jeopardy page. Filing the petition does not guarantee review or a stay.

An appellate court gives substantial deference to a trial judge’s determination that a jury was genuinely deadlocked. A challenge has a firmer basis when the record shows that counsel lacked a meaningful opportunity to be heard, the judge overlooked a practical alternative, or the stated reason did not legally justify ending the trial.

What Happens to the Case After a Mistrial

The unresolved charges remain pending after a mistrial. The Commonwealth may schedule another trial, resolve the case by agreement, or decline to proceed.

A retrial after a deadlock is not permitted if the evidence introduced at the first trial was legally insufficient to support a conviction. In that situation, double jeopardy requires dismissal rather than another attempt to prove the charge. Choy v. Commonwealth, 456 Mass. 146, 149 to 150 (2010).

When a retrial is permitted:

• The court conducts a new jury selection.
• The new jury receives no information about the first jury’s deliberations or inability to agree.
• Existing bail or release conditions continue unless the court modifies them.
• The court determines whether earlier evidentiary and pretrial rulings remain controlling or should be reconsidered.
• The parties may present additional admissible evidence.
• Prior testimony may be available for impeachment or another permitted evidentiary purpose.

The first trial gives both sides a complete view of the witnesses, examinations, exhibits, and arguments. Counsel can compare testimony from the two proceedings and use a material inconsistency when the rules of evidence permit it.

Mass. R. Crim. P. 36(b)(1)(D) ordinarily requires an ordered retrial to begin within one year after the action occasioning the retrial becomes final. The rule excludes specified periods from that calculation, including certain delays associated with motions, competency proceedings, interlocutory review, and other proceedings concerning the defendant. The date therefore must be calculated from the complete docket rather than from the mistrial date alone.

If the second trial results in a conviction, the court proceeds to sentencing in the ordinary manner. If the jury returns a not-guilty verdict, the acquittal ends the prosecution of that charge.

The case otherwise returns to the appropriate stage of the Massachusetts criminal process, with the mistrial and any resulting motions added to the court record.

Representation After a Mistrial

Attorney Joe Serpa has practiced Massachusetts criminal defense since 1995. He represents defendants in the Massachusetts District Courts, the Boston Municipal Court, and the Superior Court, including cases involving mistrials, proposed retrials, motions to dismiss, and related double jeopardy claims.

Serpa Law Office can be reached at 617.936.0201 for a confidential consultation. The firm’s reported case outcomes appear on the Massachusetts criminal defense results page.