5.02 Mental State That Is Inconsistent with
the Requisite Culpable State of Mind
Evidence has been presented of [defendantís] [carelessness, negligence, ignorance, mistake, good faith, abnormal mental condition, etc.]. Such [__________] may be inconsistent with [the requisite culpable state of mind]. If after considering the evidence of [_________], together with all the other evidence, you have a reasonable doubt that [defendant] acted [requisite culpable state of mind], then you must find [defendant] not guilty.
(1) This instruction may be given whenever the evidence of defendantís mental state, if believed, would tend to raise a reasonable doubt about the requisite culpable state of mind. See United States v. Batista, 834 F.2d 1, 6 (1st Cir. 1987) (approving an instruction that the jury . . . consider the statements and acts of appellant or any other circumstance in determining his state of mind, and to make sure that they were convinced beyond a reasonable doubt that appellant acted willfully and knowingly ); cf. United States v. Sturm, 870 F.2d 769, 777 (1st Cir. 1989) ( Jury instructions that allow a conviction even though the jury may not have found that the defendant possessed the mental state required for the crime constitute plain error. ). However, this instruction is a reinforcement of not a substitute for language instructing the jury on the exact mental state required for conviction under the relevant statute.
(2) A defendantís abnormal mental condition, just as ignorance, mistake or intoxication, may raise a reasonable doubt that the defendant acted with the requisite culpable state of mind. As the Court of Appeals for the First Circuit held in United States v. Schneider, 111 F.3d 197, 201 (1st Cir. 1997), in principle there should be no bar to medical evidence that a defendant, although not insane, lacked the requisite state of mind. In practice, the trial judge must screen such evidence for relevance, potential for confusion, reliability and helpfulness. Id.
In particular, there must be a fit between proferred expert testimony and the requisite culpable state of mind. See United States v. Meader, 914 F. Supp. 656 (D. Me. 1996), for an example of an analysis of the fit.
(3) For a discussion of the tax-crime exception to the general proposition that ignorance of the law is no defense, see United States v. Aversa, 984 F.2d 493, 500-01 (1st Cir. 1993) (citing Cheek v. United States, 498 U.S. 192, 199-201 (1991), vacated and remanded on other grounds, 510 U.S. 1069 (1994).