Crimes that schizophrenic patients commit, if they do, mainly divided into harming others, stealing, murder, and arson according to a study conducted by E. Bleuler at 1911. The time between first crime they commit and the onset of schizophrenia ranges from 5 to 10 years, and often the crime is violent, for instance harming and murder. It is common that the crime they commit is often minor, however there are some rare circumstances the crime is severe and significant. However, there were researches indicate that the probability that schizophrenia patients do not have a lower severity crime than other mental disorders.
According to Taylor, P.J in Schizophrenia and Crime: Distinctive patterns in association with data collected from chronic prisoners, there were 9% of psychological disordered, and almost every one of them has positive symptoms. There were also 8% of prisoners charged with murders had schizophrenia; in another study by Taylor, there were 121 mentally disrupted among 203 prisoners, and 90% of 121 prisoners were diagnosed as schizophrenia.
In another study conducted in Taiwan in 1996 , there were 47.6% of prisoners were diagnosed as schizophrenic; and in 1997 a study named “Analysis of murderer of under-aged female”, schizophrenia patients occupied 53.3% among the sample; in Taylor’s study (1993), he examined 1241 male prisoners and found that murderer and arsonists population have a higher prevalence of schizophrenic than the general population. Most of the victims from violet crime by schizophrenia patients are surprisingly their relatives and friends, but not strangers. In Finland, there was a study on arsonist and serious violent crime schizophrenia patients: delusion causes 1/3 of the crimes and the rest were caused by family pressure, for example discrimination or unfair treatment by family members.
