Under 18 U.S.C. § 17(b), the burden has been shifted to the defendant to prove the defense of insanity by clear and convincing evidence. This is a change from the previous federal standard set forth in Davis v. United States, 160 U.S. 469 (1895), which required the government, once some evidence of insanity had been introduced by the defendant, to prove the defendant's sanity beyond a reasonable doubt.
The Davis standard was set forth in the exercise of the Supreme Court's supervisory powers over the Federal courts and was not of constitutional magnitude. See Leland v. Oregon, 343 U.S. 790, 797 (1952). A defendant may constitutionally be required to prove his/her insanity by a standard as high as beyond a reasonable doubt. Id. at 799. It therefore follows that placing the burden on the defendant to prove the defense of insanity by clear and convincing evidence is constitutional. United States v. Freeman, 804 F.2d 1574, 1576 (11th Cir. 1986); United States v. Amos, 803 F.2d 419, 421 (8th Cir. 1986).
[cited in JM 9-18.000]