Mental disease or defect · as in force on May 31, 2026
§ 40.15 Mental disease or defect.
In any prosecution for an offense, it is an affirmative defense that when the defendant engaged in the proscribed conduct, he lacked criminal responsibility by reason of mental disease or defect. Such lack of criminal responsibility means that at the time of such conduct, as a result of mental disease or defect, he lacked substantial capacity to know or appreciate either:
1. The nature and consequences of such conduct; or
2. That such conduct was wrong.
A defendant has an affirmative defense of lack of criminal responsibility by mental disease or defect if, when acting, the condition left the defendant without substantial capacity to know or appreciate:
Marked in the text: penalties, time limits, sums of money. Editorial emphasis added by this edition; it does not appear in the statute as enacted.
This provision appears in Volume 4 — The Court Clerk: Penal Law; Volume 1 — The Court Officer in Plain English; Volume 3 — The Court Officer: Penal Law; Volume 3 — Your Career: Penal Law in Plain English.