Also known as: insanity pleas · insanity defense · NGRI
Written by attorneys · grounded in primary & secondary sources — see below
A criminal defense asserting that a mental disease or defect at the time of the offense left the defendant without substantial capacity to appreciate the wrongfulness of the conduct or to conform conduct to the requirements of law.
Ian Iverson was arrested for assault and received Miranda warnings. He remained silent during questioning. At trial he raised an insanity defense supported by expert testimony about his dissociative disorder. The prosecutor sought to introduce the silence to suggest the defense was fabricated. The court excluded the evidence because post-Miranda silence cannot rebut an insanity claim.
Isla Ireland was charged with arson after setting fire to a warehouse. Her counsel filed a written insanity notice two weeks after the pretrial-motion deadline and offered no explanation for the delay. The government moved to strike the defense. The court granted the motion because the notice was untimely and no good cause was shown.
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Isabella Ingram shot a security guard while experiencing delusions that he was a robot. At her bench trial she presented evidence that her schizophrenia prevented her from knowing the act was wrong. The court applied the jurisdiction's cognitive insanity standard and acquitted her after finding she lacked capacity to appreciate wrongfulness.
Israel Irving was charged with murder and made a preliminary showing that he would rely on an insanity defense. The state refused to provide funds for a psychiatric expert. The court ordered the state to supply the assistance because an indigent defendant raising insanity is entitled to expert help to prepare the defense.
Idina Iverson gave a confession after prolonged interrogation while medicated for bipolar disorder. She later moved to suppress the statement and raised an insanity defense. The court held a separate hearing to determine whether the confession was voluntary before allowing it to be used against the insanity claim.
Iain Irons faced murder charges and wanted to maintain an insanity defense while accepting a plea. He entered an Alford plea asserting innocence but acknowledging the evidence. The court accepted the plea without requiring him to abandon the mental-health claim for sentencing purposes.
A defendant must notify the government in writing within the time for pretrial motions or any later time the court sets. Failure to provide timely notice bars reliance on the defense unless the court finds good cause for a late filing.
No. The prosecution may not introduce post-Miranda silence to rebut or counter an insanity defense because that use would violate the implicit assurance that silence carries no penalty.
When the defendant makes a preliminary showing that an insanity defense is likely, the state must provide access to a psychiatrist to assist in preparing the defense and, when future dangerousness is at issue, for sentencing.
No. It is enough that a mental disease or defect caused the defendant to lack substantial capacity to appreciate wrongfulness or conform conduct to law at the time of the offense, even if the defendant functions normally in other contexts.
…test of psychological coercion, which promises to do for the Establishment Clause what the Durham rule did for the insanity defense. See Durham v. United States , 94 U. S. App. D. C. 228, 214 F. 2d 862 (1954). Today's opinion shows more forcefully than volumes of argumentation why our Nation's protection, that fortress…