How has diminished capacity been interpreted in criminal law?

It was only through an abundance of caution of the trial court that the jury was instructed concerning diminished capacity. Such instructions were not required based on defendant's own testimony which negated his diminished capacity defense. (People v. Carpenter (1979) 99 Cal.App.3d 527, 534, 160 Cal.Rptr. 386.) Additionally, it is extremely probable, based on the verdict, that the jury rejected any claim that defendant Polk lacked the specific intent or mental state for any of the crimes of which he was convicted. The jury found not only that defendant was guilty of the kidnaping, but also found that defendant Polk personally was armed with a firearm as to each of the counts. This court does not believe that the jury relied upon the aider and abettor theory as it made this latter finding as well. (See People v. Frierson (1979) 25 Cal.3d 142, 157, 158 Cal.Rptr. 281, 599 P.2d 587.)