§17. Insanity defense

(a) Affirmative Defense.-It is an affirmative defense to a prosecution under any Federal statute that, at the time of the commission of the acts constituting the offense, the defendant, as a result of a severe mental disease or defect, was unable to appreciate the nature and quality or the wrongfulness of his acts. Mental disease or defect does not otherwise constitute a defense.

(b) Burden of Proof.-The defendant has the burden of proving the defense of insanity by clear and convincing evidence.

(Added Pub. L. 98–473, title II, §402(a), Oct. 12, 1984, 98 Stat. 2057 , §20; renumbered §17, Pub. L. 99–646, §34(a), Nov. 10, 1986, 100 Stat. 3599 .)