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Physical Trauma May Negate Mens Rea
Evidence has been received regarding physical trauma received by the defendant during or prior to the crime charged [in count[s] ___________]. You may consider such evidence solely for the purpose of determining whether or not the defendant actually formed the specific intent and mental state elements of the crime charged [in count[s] __________], to-wit __________.
Points and Authorities
Prior to 1982 “evidence of diminished mental capacity, whether caused by intoxication, trauma or disease, [could] be used to show that a defendant did not have a specific mental state essential to an offense.” [Emphasis added.] (People v. Wetmore (78) 22 C3d 318, 323 [149 CR 265]; see also People v. Alvarez (70) 4 CA3d 913, 918-19 [84 CR 732] [trauma resulting from a knife wound sustained to defendant’s arm minutes before the killing required sua sponte instruction on diminished capacity].) In 1982, Proposition 8 (PC 25) eliminated the defense of diminished capacity while specifically authorizing the presentation of evidence of mental disease, defect or disorder (PC 28) or voluntary intoxication (PC 22), to prove that the defendant did not actually possess the requisite mens rea required by the charged offense.
Because physical trauma may affect actual formation of the requisite mens rea, such trauma may be viewed as causing a mental defect or disorder within the meaning of PC 28. Moreover, exclusion of evidence and instruction upon a defense theory which negates an essential element of the charge would implicate the defendant’s 6th and 14th Amendment rights to due process, compulsory process, and trial by jury. [See generally, FORECITE PG VII(C).]