...expert psychiatric opinion allows the offense, as defined by the law, to be doubled with a whole series of things that are not the offense itself but a series of forms of conduct, of ways of being that are of course, presented in the discourse of the psychiatric expert as the cause, origin, motivation, and starting point of the offense.
Yeah, I've had the misfortune of being on the jury in a couple of trials (not murder, but close) in which there was very little physical evidence, only circumstantial.
In these cases. it's very hard to keep folks on point in the jury room. In one trial, a couple of people were basing their decisions on which attorneys they liked the best.