To establish the social, clinical and forensic differences between murderers with schizophrenia and murderers without any psychiatric disorder and to compare their respective relationship with their victim.

We identified the socio-demographic, clinical and criminological profiles of 14 murderers with schizophrenia from 210 forensic examinations of murderers, and compared their profiles with those of murderers without any mental disorder (n=73).

Murderers with schizophrenia are characterized by a specific socio-professional status (single, living alone and jobless). Previous psychiatric history was significantly more common in the schizophrenia group than in the group of persons without mental disorder, as it was the case as regards previous contact with the police.

Schizophrenic murderers generally commit, alone, a non-premeditated murder. They usually strangle their victim in a sudden attack, whereas murderers without any pathology usually premeditate their crime. 86% of perpetrators with schizophrenia have been in a delirium at the time they committed murder, among four main themes: persecution, thought insertion, mysticism and megalomania.

Victims of murderers with schizophrenia were family members in 21% of cases, acquaintances in 57% and a stranger in 14%. The victim was known to the perpetrator significantly more often in the schizophrenia group than in the no mental disorder group (86% versus 77%, p=0,002).

The main difference between murderers with schizophrenia and murderers without any mental disorder is the psychopathology of the morbid process which underlies the homicide. The most schizophrenics’ homicide was more likely to be against intimates than strangers.