Analysis of Criminal Behavior with Mental Disorder by Forensic and Psychological Approach

Abstract

Crimes committed by the mentally ill may initially be mistaken as unmotivated or hate crimes, which may cause public anxiety and conflict between social classes. In this context, special attention is needed to secure social safety and to effectively respond against crimes committed by the mentally ill. For these purposes, comprehensive analysis of the details of such crimes, including the type of crime, the content of criminal behavior, the tool of crime, unusual behavior before and after the crime, and the triggering factor of the crime, can provide valuable information. If specific tendencies or common characteristics shared in criminal acts related to mental illness can be found, they would assist criminal investigations and determination of criminal responsibility. The authors analyzed 19 precedents of crimes with mental disorders. The results of the analysis are as follows: frequency of injured area was the highest in the face, neck, and head; perpetrator’s body (hands/feet) and knife were used the most as tools of assault; premeditation was revealed in eight cases, and crimes with active intention of harming and impulsive crimes happened at a similar frequency; schizophrenics usually committed crimes between 03:00-06:00, which is related to sleep disturbance in schizophrenia; in five cases, criminal acts—violent crimes such as murder, arson, and rape—were committed under the influence of alcohol; and homicide is related more frequently to schizophrenia, personality disorder, and intellectual disability.