Intended for healthcare professionals


Mental illness in people who kill strangers: longitudinal study and national clinical survey

BMJ 2004; 328 doi: (Published 25 March 2004) Cite this as: BMJ 2004;328:734
  1. Jenny Shaw (Jennifer.J.Shaw{at}, senior lecturer in forensic psychiatry1,
  2. Tim Amos, clinical research fellow1,
  3. Isabelle M Hunt, research associate1,
  4. Sandra Flynn, research assistant1,
  5. Pauline Turnbull, research assistant1,
  6. Navneet Kapur, senior lecturer in psychiatry1,
  7. Louis Appleby, professor of psychiatry1
  1. 1National Confidential Inquiry into Suicide and Homicide by People with Mental Illness, Centre for Suicide Prevention, School of Psychiatry and Behavioural Sciences, University of Manchester, Manchester M13 9PL
  1. Correspondence to: J Shaw
  • Accepted 21 January 2004


Objectives To establish changes over time in the frequency of homicides committed by strangers, and to describe the personal and clinical characteristics of perpetrators of stranger homicides.

Design Longitudinal study and national clinical survey.

Participants People convicted of homicide in England and Wales between 1996 and 1999 and whether the victim was known to the perpetrator.

Setting England and Wales.

Main outcome measure Characteristics of perpetrators of homicides according to whether victims were strangers or not.

Results Stranger homicides increased between 1967 and 1997, both in number and as a proportion of all homicides. No increase was found, however, in the number of perpetrators placed under a hospital order after homicide, whether all homicides or stranger homicides only. 358 of 1594 (22%) homicides were stranger homicides. In these cases the perpetrator was more likely to be male and young. The method of killing was more likely to be by hitting, kicking, or pushing (36% (130 of 358) for victims who were strangers to the perpetrator compared with 14% (145 of 1074) for victims who were known). Perpetrators were less likely to have a history of mental disorder (34%, n = 80 ν 50%, n = 142), a history of contact with mental health services (16%, 37 of 234 ν 24%, 200 of 824), and psychiatric symptoms at the time of the offence (6%, n = 14 ν 18%, n = 143). They were more likely to have a history of drug misuse (47%, n = 93 ν 37%, n = 272); alcohol (56%, n = 94 ν 41%, n = 285) or drugs (24% n = 44 ν 12%, n = 86) were more likely to have contributed to the offence.

Conclusions Stranger homicides have increased, but the increase is not the result of homicides by mentally ill people and therefore the “care in the community” policy. Stranger homicides are more likely to be related to alcohol or drug misuse by young men.


  • Funding The National Confidential Inquiry into Suicide and Homicide by People with Mental Illness is funded by the National Institute for Clinical Excellence.

  • Contributors JS, TA, and LA contributed to the design, data collection, data analysis, and drafting the paper. JS and LA are grant holders on the project. IH, SF, PT, and NK contributed to data collection and analysis and drafting the paper. JS will act as guarantor for the paper. The guarantor accepts full responsibility for the conduct of the study, had access to the data, and controlled the decision to publish.

  • Conflict of interest LA is currently seconded part time to the Department of Health as National Director for Mental Health and in this capacity provides advice on mental health policy.

  • Ethical approval This study was approved by the multi-centre research ethics committee.

  • Accepted 21 January 2004
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