The States have traditionally exercised broad power to commit persons found to be mentally ill. The substantive limitations on the exercise of this power and the procedures for invoking it vary drastically among the States. The particular fashion in which the power is exercised -- for instance, through various forms of civil commitment, defective delinquency laws, sexual psychopath laws, commitment of persons acquitted by reason of insanity -- reflects different combinations of distinct bases for commitment sought to be vindicated. The bases that have been articulated include dangerousness to self, dangerousness to others, and the need for care or treatment or training.
A person charged by a State with a criminal offense who is committed solely on account of his incapacity to proceed to trial cannot be held more than the reasonable period of time necessary to determine whether there is a substantial probability that he will attain that capacity in the foreseeable future. If it is determined that this is not the case, then the State must either institute the customary civil commitment proceeding that would be required to commit indefinitely any other citizen, or release the defendant. Furthermore, even if it is determined ...