Section 15.21 Jury Determination and Instructions

• Library: Criminal Practice 2012 Supp

D. (§15.21) Jury Determination and Instructions

Whether the defendant has a mental disease or defect excluding responsibility for the defendant’s conduct is an issue solely for the jury to decide. Section 552.030.6, RSMo 2000. There can be no directed verdict of not guilty by reason of mental disease or defect. This is always a jury question unless the jury is waived.

The jury can reject the defense even if no contradictory medical evidence is offered by the state. State v. West, 575 S.W.2d 257 (Mo. App. W.D. 1978).

If substantial evidence is not introduced by the accused to refute the presumption of § 552.030.6, the trial court is not required to instruct
the jury on the defense of mental disease or defect. State v. Thomas,
625 S.W.2d 115 (Mo. 1981); State v. Bacon, 501 S.W.2d 499 (Mo. App. W.D. 1973).

Evidence of mental disease or defect is admissible to prove that the defendant did not have a state of mind that is an element of the offense, and failure to give a manslaughter instruction in a murder prosecution when there is...