Plain-English summary
Court: Insanity-Based Not Guilty Verdict Is an Acquittal that Bars Retrial
The Supreme Court unanimously held that a jury verdict finding a defendant not guilty by reason of insanity on a murder charge is an acquittal for purposes of the Fifth Amendment’s Double Jeopardy Clause. That acquittal prevents a second prosecution for the same offense even if the jury returned inconsistent verdicts on related counts.
Why this matters
This decision clarifies that any jury verdict that favors the defendant on the ultimate question of criminal liability — including verdicts finding not guilty by reason of insanity — functions as an acquittal and prevents the government from trying the defendant again for the same offense. It protects defendants from repeated prosecutions when a jury has already resolved the core question of guilt in the defendant’s favor, even if other jury answers appear inconsistent.
Who may feel it
- Defendants tried on criminal charges who receive jury findings of not guilty by reason of insanity
- Prosecutors and state governments seeking retrial after mixed or inconsistent jury verdicts
- Criminal defense attorneys advising clients about the consequences of insanity defenses
- Courts addressing the effect of verdict forms that include both acquittals and convictions
Key questions
- Does a jury’s finding that a defendant is not guilty by reason of insanity count as an acquittal under the Double Jeopardy Clause?