An insanity defense is a strategy used in court to excuse a defendant from being punished for committing a crime. What constitutes a valid version of this type of defense is not the same in all jurisdictions. Some jursidictions do not require that the defendant be remorseful for committing the crime in order to be free of liability. Most, if not all, jurisdictions require the defendant to have been insane at the time of the crime, as opposed to at the time of trial.
The insanity defense is available in most states within the United States and, to varying degrees, in many other countries as well. In the United States, Idaho, Kansas, Montana, and Utah do not recognize this defense. Of those states that do permit it, the standard of proof required for it to be valid varies. In federal courts, the defendant must prove insanity by clear and convincing evidence. In some state courts, the defendant must prove insanity by a preponderance of the evidence, while other state courts require that the plaintiff disprove insanity beyond a reasonable doubt.
The idea behind permitting the insanity defense is essentially that an individual is only deserving of punishment for a crime if he or she is capable of understanding the difference between right and wrong. Since it is believed that an insane person is incapable of making sound decisions, many believe such defendants should not be liable for their crimes.
The insanity defense is not without opponents. Some individuals believe that it is frequently used to excuse or justify criminal activity. They believe it is too often employed by those who have broken the law willfully and seek to escape punishment by claiming insanity.
Typically, a person judged not guilty by reason of insanity is required to undergo psychiatric evaluation and treatment. However, in cases of temporary insanity, such treatment may not be mandatory. Often, those acquitted for reasons of insanity are placed in mental institutions for treatment.
Unlike those convicted of crimes, individuals who have been judged insane are usually not relegated to institutions for a specific period of time. Instead, they are held in mental institutions until those in authority conclude they are no longer a threat to themselves or others. Often, those charged with such decisions choose to err on the side of caution and individuals acquitted because of insanity may spend quite a while in mental institutions. In some cases, such defendants may even spend more time in mental institutions than they would have spent in prison had they been convicted.
In the United States, a distinction is usually made between a defendant who is insane and a defendant suffering from a mental illness. Generally, it is believed that a person can be mentally ill, yet still sane. As such, a person with a recognized mental illness may not be able to successfully use an insanity defense. The court system may still judge such a defendant liable, rendering a judgment of guilty, guilty but mentally ill, or guilty but insane.