How often is the insanity defense invoked? In what kinds of cases? And how often does it succeed? Although cases invoking the insanity defense often receive much media attention, the defense is actually not raised very often. Virtually all studies conclude that the insanity defense is raised in less than 1 percent of felony cases, and is successful in only a fraction of those1. The vast majority of those that are successful are the result of a plea agreement in which the prosecution and the defense agree to a not guilty by reason of insanity (NGRI) plea.
A major 1991 eight-state study commissioned by the National Institute of Mental Health found that less than 1 percent of county court cases involved the insanity defense, and that of those, only around one in four was successful. Ninety percent of the insanity defendants had been diagnosed with a mental illness. About half of the cases had been indicted for violent crimes; fifteen percent were murder cases.
What happens in states where there is no insanity defense? Three states - Montana, Idaho, and Utah - do not allow the insanity defense. Defendants must still be found competent to stand trial, and they may introduce evidence of a mental disease or defect as evidence that they did not possess the requisite intent or state of mind to be found guilty.
"They plead insanity Sir. No not the defendant , the prosecution, sir. The defendant pleads sanity."
ReplyDeleteI worked at a 'not-guilty-by-reason-of-insanity not-prison' and I can tell you that about half of the 'residents' weren't insane. They were in for murder and assaults and had good lawyers. Spend 5-6 years there, clear your psych evaluations and you get released.
ReplyDeleteAnd the key in every case is the prosecution allowed the plea for insanity because a plea is equal to a win in court but takes a lot less work to get. It's why you get people charged with a whole list of heinous crimes and the suspect will cop to a low-level felony if he/she/it is unlucky, but usually to a high-level misdemeanor (often without having to register as a sex offender because he/she/it didn't plea or take an Alford Agreement (I know I'm guilty but I'm not going to say it) for the sex crimes.