There is a brief history behind the insanity defense that may put things into perspective for how it works. In the 19th Century (1843, to be exact) a man named Daniel M’Naghten, a woodworker, believed that he was a target of a conspiracy between the pope and Robert Peel. That year, he traveled to 10 Downing Street to ambush Peel but mistakenly shot and killed his secretary instead. During his extensive trial, psychiatrists stepped in and testified that he was actually delusional, and a jury agreed by reason of insanity. This is how the insanity defense came to be today.

What is an Insanity Defense? 

If you as a defendant are found to be not guilty by reason of insanity, this means that a judge or jury believes that you were legally insane when you committed a crime. In many cases, you may be found guilty but sentenced to a less severe punishment due to the nature of your impairment. In many cases, somebody will be permitted to plead insanity if they had no idea that what they were doing was wrong or acted on control or impulse. Courts take many rules into consideration when “testing” to find if you were actually deemed insane at the time of the crime. In California, the state uses what is known as the M’Naghten Rule and the burden of proof is on the defendant. Across the states, you may find any one of the following tests:

  • M’Naghten Rule: They must be able to prove that you did not understand what you did because you cannot distinguish right from wrong.
  • Irresistible Impulse Test: You were unable to control your impulses due to the mental disease.
  • Durham Rule: No matter what diagnosis you have, your mental defect resulted in a criminal act.
  • Model Penal Code Test: You have a diagnosed mental defect and because of such, you failed to understand what you were doing was wrong.

There are some states today that do not use the insanity defense, but California permits it. If you are wondering what the laws are for your state and wish to speak to us today, give us a call for more information. At The Law Office of Peter Blair, we are willing to help.