Also known as: dementedly · insane · of unsound mind · mentally incompetent
Written by attorneys · grounded in primary & secondary sources — see below
A mental condition in which a person lacks sound mind and rational capacity.
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Darius Dixon, a demented adult roofer, unhooked his safety harness near a roof edge to retrieve a tool. The site owner raised contributory negligence after Dixon fell. Because he was demented, the court declined to measure his conduct by the reasonable person standard that applies to non-insane adults.
A defendant charged with murder presented evidence of mental weakness short of full legal insanity. The trial court refused an instruction that would reduce the offense to second-degree murder. The Supreme Court later considered whether such evidence required a lesser-degree instruction.
A defendant sought an instruction that mental deficiency short of legal insanity could reduce first-degree murder to second degree. The court rejected the request. The Supreme Court examined whether such evidence must be considered in grading the offense.
Adults sought to operate a group home. The city denied the permit under an ordinance that singled out facilities for the mentally handicapped. The Supreme Court reviewed whether the classification violated equal protection.
A capital defendant requested state-funded psychiatric assistance to prepare an insanity defense. The trial court denied the request. The Supreme Court considered whether due process required such assistance when sanity was genuinely at issue.
An individual spoke with an informant who secretly recorded the conversation at government direction. She later challenged admission of the recording. The Supreme Court addressed whether the Fourth Amendment barred use of the evidence obtained through the informant.
Yes. Once a court adjudicates mental incompetence and places property under guardianship, the ward lacks capacity to incur contractual duties, rendering purported contracts void rather than merely voidable.
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A demented adult is exempt from the reasonable person standard that applies to non-insane adults. The court instead applies a modified inquiry that accounts for the mental condition rather than holding the actor to the objective adult benchmark.
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No. Due process prohibits the prosecution from using a defendant's post-Miranda silence to rebut an insanity defense, because the warnings implicitly assure that silence carries no penalty.
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…Eriswell was not a criminal case at all, but a Crown suit against the inhabitants of a town to charge them with care of an insane pauper. Id. , at 707-708, 100 Eng. Rep., at 815-816. It is relevant only because the judges discuss the Marian statutes in dicta. One of them, Buller, J., defended admission of the…