Homicide of Strangers by People with a Psychotic Illness
- Olav Nielssen2,3,
- Dominique Bourget4,
- Taina Laajasalo5,
- Marieke Liem6,
- Alain Labelle7,
- Helina Häkkänen-Nyholm8,
- Frans Koenraadt9,10 and
- Matthew M. Large1,11
- 2Clinical Research Unit for Anxiety and Depression, St Vincent's Hospital, Sydney
- 3Discipline of Psychological Medicine, University of Sydney
- 4Integrated Forensic Program and Schizophrenia Program, Royal Ottawa Mental Health Centre, Associate Professor of Psychiatry, University of Ottawa, Ottawa, Ontario, Canada
- 5Department of Psychology, PO Box 9, 00014 University of Helsinki, Finland
- 6Utrecht University, Faculty of Law, Willem Pompe Instituut for Criminal Law & Criminology, Janskerkhof 16, 3512 BM Utrecht, The Netherlands
- 7Schizophrenia Program, Royal Ottawa Mental Health Centre; Associate Professor of Psychiatry, University of Ottawa, Ottawa, Ontario, Canada
- 8Forensic Laboratory, National Bureau of Investigation & Department of Psychology, University of Helsinki, PO Box 285, 01301 Vantaa, Finland
- 9Utrecht University, Faculty of Law,Willem Pompe Instituut for Criminal Law & Criminology, Janskerkhof 16, 3512 BM Utrecht,The Netherlands
- 10Pieter Baan Centre, Gansstraat 170, 3582EP Utrecht, The Netherlands
- 11School of Psychiatry, University of New South Wales. Sydney, NSW, Australia
- 1To whom correspondence should be addressed; The Euroa Centre, Prince of Wales Hospital, Barker St, Randwick, Sydney, NSW 2034, Australia; tel: 612-9383-2222, fax: 612-9382-2944, e-mail: mmbl{at}bigpond.com.
Abstract
Background: The homicide of strangers by people with psychosis, referred to here as “stranger homicides,” are rare and tragic events that generate adverse publicity for mental health services and have resulted in significant changes in mental health policy and law. Aim: To estimate the incidence of stranger homicides, using data from previously published studies, and to compare the characteristics of psychotic offenders who killed strangers with the characteristics of those who killed a close relative. Method: Meta-analysis of the population-based studies of homicide by persons suffering from a psychosis in which the number of subjects who killed strangers was also reported. Characteristics of stranger homicide and family homicide offenders were examined in a multicenter case–control study of homicide during psychotic illness in four high-income countries. Results: A pooled estimate of 1 stranger homicide per 14.3 million people per year (95% confidence interval, 1 in 18.9 million to 1 in 11.5 million people per year) was calculated by meta-analysis of 7 studies. The characteristics of the 42 stranger homicide offenders from New South Wales [NSW], Quebec and Eastern Ontario, Finland, and the Netherlands were identified. Twenty seven (64%) of these had never previously received treatment with antipsychotic medication. The stranger homicide offenders were more likely to be homeless, have exhibited antisocial conduct, and had fewer negative symptoms than those who killed family members. The victims of stranger homicide were mostly adult males and the homicides rarely occurred in the victim’s home or workplace. Conclusions: Stranger homicide in psychosis is extremely rare and is even rarer for a patient who has received treatment with antipsychotic medication. A lack of distinguishing characteristics of stranger homicide offenders and an extremely low base rate of stranger-homicide suggests that risk assessment of patients known to have a psychotic illness will be of little assistance in the prevention of stranger homicides.
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- © The Author 2009. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oxfordjournals.org.
