In the United States, trials in which a defendant pleads not guilty by reason of insanity represent 1% of all criminal cases, and the defense is legitimately verified only in 25% of these cases (Giannetakis, 2011). The plea of ​​not guilty by reason of insanity, or NGRI, is a legal defense that a defendant might use to argue that he or she was not guilty of a crime by reason of insanity (Butcher, Hooley, & Mineka, 2014). The effort to define insanity in a legal sense began in 1843 and continued until 1984. Starting from the “M'Naghten Rule” or the rule of “distinguishing right from wrong” because it is assumed that people are stable, but one can demonstrate that at the time of the act they were committing, they were struggling under such a defect of reason (due to disease of the mind) that they did not know the nature and quality of the act they were committing or, if they knew that they were committing the act, they did not know that what they were doing was wrong (Butcher, et. al, 2014). Secondly there was the Irresistible Impulse Rule in 1887, which suggests that defendants might not be responsible for their acts, even when they knew what they were doing was wrong (under the M'Naghten rule) – if they lost control. choose between right and wrong. That is, they could not avoid performing the act in question because they were forced to commit it beyond their will. Moving forward to 1954, Judge David Bazelon of the United States Court of Appeals was not confident in the precedents allowed for an adequate presentation of established scientific knowledge of mental illness, and recommended a test that relied on this knowledge. According to this rule, which is often called the “product test” (Durham rule), the accused is not illegitimate… middle of paper… psychology of the legal system. With these defendants who are truly mentally disturbed, I have empathy for them because I don't entirely believe that it's their fault that they are like this. There may be a chemical imbalance that causes these violent outrages and risky acts. However, those who commit these offenses should be punished in every way possible. I believe the NGRI should be eliminated because it gives prisoners an easy way out of punishment. What really bothered me was reading about criminals lying about having a mental illness. The man who received a more serious sentence simply for faking mental illness deserved it. Others who claim to be insane may indeed need treatment in mental institutions, but the places are filled because of those who lied. My final opinion on the NGRI is that if you commit a crime, you must suffer the consequences.