When does double jeopardy attach?

• A. After a hung jury
• B. At the start of trial
• C. After a mistrial
• D. After a not guilty verdict

Answer: (D)

Double jeopardy protection takes effect as soon as the criminal trial properly begins. In a jury trial, that moment is when the jury is sworn in; in a bench trial, it’s when the judge first begins to hear evidence (often marked by the first witness being sworn). Until that point, jeopardy hasn’t attached, so the State could in theory retry after certain trial terminations.

Why this matters here: a hung jury or a mistrial occurs after jeopardy has already attached, so they do not mark when jeopardy attaches. A not guilty verdict ends jeopardy, not starts it. Therefore the moment the trial begins—specifically, when the jury is sworn or when evidence begins in a non-jury trial—is the correct point at which double jeopardy attaches.