The California Supreme Court has unan­i­mous­ly ruled that a defen­dant may be spared the death penal­ty because he is men­tal­ly defi­cient in one area, even if his IQ score falls in the nor­mal range. The deci­sion gives judges broad­er dis­cre­tion to spare defen­dants from exe­cu­tion for rea­sons of men­tal impair­ment and clar­i­fies a 2005 rul­ing that allowed those on death row to chal­lenge their sen­tences on the grounds of men­tal retar­da­tion. The court ruled that tri­al courts may give greater weight to cer­tain kinds of evi­dence than oth­ers because the legal def­i­n­i­tion of men­tal retar­da­tion does not rely on a fixed IQ score.

The California Supreme Court issued the rul­ing as it reject­ed a low­er court deci­sion that ​“full scale” IQ scores — com­pos­ites of tests of var­i­ous men­tal fac­ul­ties — are the best way to mea­sure intel­lec­tu­al func­tion­ing. The Justices ruled that courts may give greater weight to one mea­sure­ment of IQ over anoth­er and that the best way to mea­sure intel­lec­tu­al func­tion­ing may vary from case to case. It stat­ed that the law should not dic­tate how to mea­sure intellectual functioning.

“The ques­tion of how best to mea­sure intel­lec­tu­al func­tion­ing in a giv­en case is thus one of fact to be resolved in each case on the evi­dence, not by appel­late pro­mul­ga­tion of a new legal rule,” wrote Justice Katheryn Mickle Werdegar.

The California Supreme Court rul­ing could affect at least 28 peo­ple cur­rent­ly on California’s death row, and anoth­er 8 who are fac­ing cap­i­tal charges and are claim­ing men­tal retar­da­tion before tri­al.
(Los Angeles Times, April 13, 2007). See Mental Retardation.
To receive DPIC’s week­ly e‑mail newslet­ter that sends sum­maries of the week’s news on the death penal­ty to your mail­box, send an e‑mail to update@​deathpenaltyinfo.​org with the sub­ject line SUBSCRIBE.

Citation Guide