10 U.S.C. § 850a (ARMED FORCES)
§ 850a. Art. 50a. Defense of lack of mental responsibility
(a) It is an affirmative defense in a trial by court-martial that, at the time of the commission of the acts constituting the offense, the accused, as a result of a severe mental disease or defect, was unable to appreciate the nature and quality or the wrongfulness of the acts. Mental disease or defect does not otherwise constitute a defense.
(b) The accused has the burden of proving the defense of lack of mental responsibility by clear and convincing evidence.
(c) Whenever lack of mental responsibility of the accused with respect to an offense is properly at issue, the military judge, or the president of a court-martial without a military judge, shall instruct the members of the court as to the defense of lack of mental responsibility under this section and charge them to find the accused—
(1) guilty;
(2) not guilty; or
(3) not guilty only by reason of lack of mental responsibility.
(d) Subsection (c) does not apply to a court-martial composed of a military judge only. In the case of a court-martial composed of a military judge only, whenever lack of mental responsibility of the accused with respect to an offense is properly at issue, the military judge shall find the accused—
(1) guilty;
(2) not guilty; or
(3) not guilty only by reason of lack of mental responsibility.
(e) Notwithstanding the provisions of section 852 of this title (article 52), the accused shall be found not guilty only by reason of lack of mental responsibility if—
(1) a majority of the members of the court-martial present at the time the vote is taken determines that the defense of lack of mental responsibility has been established; or
(2) in the case of a court-martial composed of a military judge only, the military judge determines that the defense of lack of mental responsibility has been established.
(Added Pub. L. 99–661, div. A, title VIII, § 802(a)(1), Nov. 14, 1986, 100 Stat. 3905; Pub. L. 114–328, div. E, title LVII, § 5233, Dec. 23, 2016, 130 Stat. 2915.)
heading: Amendment of Subsection (c)
text: Pub. L. 114–328, div. E, title LVII, § 5233, title LXIII, § 5542, Dec. 23, 2016, 130 Stat. 2915, 2967, and Ex. Ord. No. 13825, Mar. 1, 2018, 83 F.R. 9889, provided that, except as otherwise provided, effective on Jan. 1, 2019, as designated by the President, with implementing regulations and provisions relating to applicability to various situations, subsection (c) is amended by striking “, or the president of a court-martial without a military judge,”. See 2016 Amendment note below.
heading: Amendments
text: 2016—Subsec. (c). Pub. L. 114–328, in introductory provisions, struck out “, or the president of a court-martial without a military judge,” after “the military judge”.
heading: Effective Date of 2016 Amendment
text: Amendment by Pub. L. 114–328 effective on Jan. 1, 2019, as designated by the President, with implementing regulations and provisions relating to applicability to various situations, see section 5542 of Pub. L. 114–328 and Ex. Ord. No. 13825, set out as notes under section 801 of this title.
heading: Effective Date
text: Pub. L. 99–661, div. A, title VIII, § 802(b), Nov. 14, 1986, 100 Stat. 3906, provided that: “Section 850a of title 10, United States Code, as added by subsection (a)(1), shall apply only to offenses committed on or after the date of the enactment of this Act [Nov. 14, 1986].”