Sez Wikipedia:
According to an eight-state study, the insanity defense is used in less than 1% of all court cases and, when used, has only a 26% success rate.[4] Of those cases that were successful, 90% of the defendants had been previously diagnosed with mental illness.[4]
Sounds like a pretty desperate hail-Mary defense strategy unless his lawyers can pony up evidence of a prior diagnosis. In the United States even people who have genuine, clear-cut cases of mental illness often end up doing hard time (with little or no access to mental health care).
