Profiling Overkill Cases Perpetrated by Individuals With Psychotic Illness: A Cross-Sectional Study From Türkiye.

Area of Science:

• Forensic Psychiatry
• Psychopathology
• Criminology

Background:

• Individuals with psychosis are a minority of homicide perpetrators but overrepresented in 'overkill' cases.
• Little is known about the characteristics of homicide perpetrators with psychosis who use excessive violence.

Purpose of the Study:

• To describe the characteristics of individuals with psychosis who commit homicide with excessive force.
• To identify subgroups within this population.

Main Methods:

• A 10-year cross-sectional clinical chart review of 183 homicide perpetrators with psychotic illness meeting overkill criteria.
• Exploratory cluster analysis of background, clinical, and homicide-related factors.

Main Results:

• Most perpetrators were men (91%) with long-standing illness, impaired psychosocial functioning, and prior psychiatric contact.
• Victims were often relatives, killed in private settings with readily available weapons during active psychosis.
• Two subgroups identified: psychosis-dominant/domestic and externalizing/premeditated, the latter showing more planning, crime/substance use history, and peer targeting.

Conclusions:

• The profile of overkill perpetrators with psychosis shows heterogeneity, with two distinct subgroups identified.
• Findings suggest focusing assessments and risk management, including environmental strategies for domestic attacks.
• Most perpetrators had prior contact with mental health services.