People v. Drew

Opinion

TOBRINER, J.

For over a century California has followed the M’Naghten1 test2 to define the defenses of insanity and idiocy. The deficiencies of that test have long been apparent, and judicial attempts to reinterpret or evade the limitations of M’Naghten have proven inadequate. We shall explain why we have concluded that we should discard the M’Naghten language, and update the California test of mental incapacity as a criminal defense by adopting the test proposed by the American Law Institute3 and followed by the federal judiciary and the courts of 15 states. _

*337Understandably, in view of…