When does jeopardy "attach" (and what does that mean)?
Many of us are familiar with the Constitutional prohibition on double jeopardy, codified in the Fifth Amendment. We may be perplexed then when we see someone being tried more than once for the same offense. Isn't this putting them in double jeopardy?
The answer to that is somewhat less than straightforward to the average person, given the way courts have interpreted this particular clause of the Fifth Amendment. One of the boundaries that courts have established that limits our Constitutional protection against "twice be[ing] put in jeopardy of life or limb" is the concept of attachment.
When jeopardy is said to "attach" is the first time in a legal proceeding at which courts legally recognize the accused has been put in jeopardy of life or limb as intended by the Fifth Amendment.
We might consider ourselves in jeopardy of life and limb when a police officer points a gun at or shoots us, tasers us, tackles us and pins us painfully to the ground with a boot on our back, handcuffs us and imprisons us, etc. None of those things, however, are considered in the American legal system to put us in jeopardy for purposes of the Fifth Amendment prohibition against double jeopardy.
Neither does being indicted or charged put us in such jeopardy, according to the courts. Neither does being held in pre-trial detention without bond. Neither does being brought into pre-trial hearings or even selecting a jury "start the clock", so to speak, on jeopardy.
Jeopardy attaches at different times depending on what route a case takes through the legal system—trial by jury, bench trial, plea bargain, or juvenile proceeding. In a trial by jury, the rule is that jeopardy attaches when a trial jury is sworn.
In Downum v. United States (1963), the United States Supreme Court ruled against a second prosecution of a defendant whose first trial ended immediately after the jury had been sworn. Even though both sides said that they were ready to proceed at the start of the trial, after the jury was selected and sworn, the prosecutor announced that a key witness was not present. The judge discharged the jury, and the case was called again two days later, at which time the defendant argued that this was double jeopardy. The Supreme Court agreed.
Further, in Crist v. Bretz (1978), the Court held that "the federal rule that jeopardy attaches when the jury is empaneled and sworn is an integral part of the constitutional guarantee against double jeopardy."
In Martinez v. Illinois (2014), the Court again reiterated this rule, stating that "The Illinois Supreme Court’s error was consequential, for it introduced confusion into what we have consistently treated as a bright-line rule: A jury trial begins, and jeopardy attaches, when the jury is sworn."
This rule applies to trial by jury in all courts in the United States and not just federal courts.
As legal theory and practice continue to evolve, there are some grey areas in jurisprudence as regards the attachment of jeopardy. For instance, some courts have held that if someone is tried in a court that lacks jurisdiction over them, then jeopardy never attached even if a jury was sworn. Because jeopardy never attached, retrial of the individual in a court with proper jurisdiction would not necessarily be barred. Jeopardy may also be considered by some courts not to have attached in a trial where an acquittal has been achieved through fraud or collusion. Situations like these are uncommon exceptions to the rule.