The Insanity Defense in California

There is no functional difference between temporary and permanent insanity under California law. The sole issue in California is the status of the defendant’s sanity at the time of the crime. The method of determining a defendant’s sanity is the two pronged M’Naghten rule.

1) The first prong requires a defendant to understand the nature and quality of his or her act.

2) The second prong requires the defendant to be able to distinguish between right and wrong.

A defendant who cannot satisfy both of these prongs is statutorily insane.

The M’Naghten Rule is fairly consistent across the U.S. The origin of the M’Naghten Rule is the 1843 M’Naghten case, where a British citizen named Daniel M’Naghten shot and killed the secretary of the English Prime Minister. The court acquitted M’Naghten “by reason of insanity,” and he was placed in an asylum for the rest of his life. However, after public scrutiny, Queen Victoria ordered the high courts to develop a consistent legal test for insanity. Thus, the “M’Naghten rule” became the standard method for determining insanity in England and the United States, and remains as such in California along with twenty other states.

The only serious changes in California regarding the testing of insanity, that is applied and not merely codified, is a 1994 amendment to the penal code that prevents California courts from finding a defendant insane solely on the basis of a personality or adjustment disorder, a seizure disorder, or addiction to, or abuse of intoxicating substances.

The process of declaring your insanity as a defendant begins at the arraignment hearing, where one can plead not guilty by reason of insanity.  If a defendant can convince the jury at their trial that they are not guilty by reason of insanity, then they will be sent to a state mental hospital instead of prison. However, even when an insanity plea is successful, it is rare that those acquitted walk entirely free. In almost all cases, a verdict of not guilty by reason of insanity prompts a judge to commit defendants to a state mental hospital until health officials determine they do not pose a serious threat to public safety. However, there are exceptions. In January of 2013, a California mother accused of drowning her 3-year-old child was found not guilty by reason of insanity and the judge deemed her ready to reenter society.

If you have any questions regarding the use of the insanity defense in California, or about a situation that applies to this, feel free to discuss it with me.