Introduction

Retrial After Mistrial or Reversal

Introduction

The Fifth Amendment provides that no person shall be subject for the same offence to be "twice put in jeopardy of life or limb."¹ That text seems to settle the question this chapter takes up, but it leaves a gap. A first proceeding has ended without a clean final judgment. The jury may have been unable to agree, the judge may have declared a mistrial for some other reason, or an appellate court may have set aside a conviction. In each case the prosecutor announces a second trial and the defendant objects. Whether the Clause blocks the prosecutor depends on a question the words do not answer: when does a trial count as the government's one complete opportunity to convict?

The three endings share a single tension. A second trial costs the defendant more time, money, and stress, and it can give the government a rehearsal of its case, a chance to repair its weak points, and a look at the defense strategy.² Those burdens fall on the defendant whether or not the first trial reached a verdict, which is why an unfinished trial still engages the Clause. Yet a failed or flawed trial does not always mean the government has had its full chance. A jury that cannot agree has decided nothing, and a conviction reversed for an error at trial leaves the question of guilt open. The answer therefore turns on why the first proceeding ended. The main line runs between endings that reflect a failure of the process, where the government is generally free to try again, and endings that amount to an acquittal or its equivalent, which the government cannot undo by trying again.³

The analysis moves in a fixed order. The first question is whether jeopardy attached at all, because a proceeding that ends before that point leaves the prosecutor free to file the same charges again.⁴ The second is how the first proceeding actually ended: by deadlock, by a mistrial declared for another reason, or by reversal of a conviction on appeal. The third is whether the reason for that ending is one the law treats as leaving the government free to retry. Only the first question is a threshold, since retrial becomes a constitutional problem only once jeopardy has attached. In a jury trial that moment arrives when the jury is empaneled and sworn, and from then on the defendant is generally protected against being retried for the same offense, as Crist v. Bretz held.⁵ The first section below therefore begins with that moment and with what it means for a trial that never produced a verdict.