One of the most important mental diseases is Schizophrenia, which in it, thoughts, emotions and feeling of patient have changed and deviated and caused to disorder performance for them. The most characteristics of this disease are further tendency to isolation, separation and loneliness. They abhor the external universe and tend to isolation. They can become delinquent exceptionally because of their imaginations and in this way, they can be entered to criminal events. These patients create wrongdoing for some reasons, including: 1.Their delusions and hallucinations which are created by their psychosis, brain damages and misuse of drugs. 2. Having some disorders which cause impulsive and unexpected behavior. 3. Personality disorders. 4. Having an excitability mood, low tolerance and neurotic circumstances, but in special situations, they have legitimated excuses of criminal liability and in some circumstances they haven't, which we have mentioned and illustrated perfectly in this essay.