The following excerpt is from Montiel v. Chappell, Case No. 1:96-cv-05412-LJO-SAB (E.D. Cal. 2014):
right from wrong at the time of the offense. People v. Skinner, 39 Cal. 3d 765, 782 (1985). The 1982 statute also codified a 1978 amendment abolishing the defense of diminished capacity. California Penal Code section 28(a) provides that evidence of mental illness may not be admitted to show or negate the capacity to form any mental state, but it is admissible on the issue of whether the accused actually formed the required specific intent, premeditated, deliberated, or harbored malice aforethought, when a specific intent crime is charged.
The above passage should not be considered legal advice. Reliable answers to complex legal questions require comprehensive research memos. To learn more visit www.alexi.com.