Definition - What does Temporary Insanity mean?
Temporary insanity is a fleeting state of mind in which a person does not possess the proper mental capacity to be responsible for his or her actions. Criminal defendants sometimes claim that they were experiencing temporary insanity while they committed a crime. This is usually an attempt to justify their actions, and to possibly get a reduced sentence.
Justipedia explains Temporary Insanity
Temporary insanity pleadings that are found to be legitimate can reduce a sentence. However, there can often be trouble in validating whether or not a crime was committed under a period of temporary insanity. Temporary insanity only lasts for a short period of time. So, if a person robs a bank while experiencing temporary insanity, his or her mental state may be normal hours later. This would make it very difficult for a psychiatrist to then evaluate the person to determine if he/she was temporarily insane during the crime.