When evidence of mental or physical illness can be used in court

Evidence that the defendant was affected by a physical or mental disease, disorder, or defect is admissible whenever it is relevant to prove that the defendant did or did not have a state of mind that is required to establish an element of the offense. [L 1972, c 9, pt of §1; am L 2006, c 230, §5] COMMENTARY ON §704-401 This section accords to evidence of physical or mental disease, disorder, or defect its full evidentiary significance. It assures "admissibility [of such evidence] co-extensive with its relevancy to prove or disprove a material state of mind."[1] While some jurisdictions have refused to admit medical evidence of the defendant's mental state other than on the issue of the complete foreclosure of defendant's responsibility, this all-or-nothing approach is totally inconsistent with the concept which accords certain states of mind legal significance. Any evidence relevant to prove or disprove the requisite state of mind ought to be admissible. In its most recent case in this area, Hawaii has adopted the approach taken in this section. In a case involving a charge of murder (which under the previous definition requires malice, premeditation, and deliberation), where the defendant had raised the issues of "insanity" and lack of "malice", evidence of a defendant's mental disease, disorder, or defect was held to be admissible on the issue of the defendant's ability to harbor malice, even if the defendant was considered "sane" and responsible.[2] Furthermore, the defendant was entitled to have the jury specifically instructed on this point.[3] SUPPLEMENTAL COMMENTARY ON §704-401 Act 230, Session Laws 2006, amended this section by making technical nonsubstantive amendments. __________ §704-401 Commentary: 1. M.P.C., Tentative Draft No. 4, comments at 193 (1955). 2. State v. Moeller, 50 Haw. 110, 433 P.2d 136 (1967). 3. Id.