BACKGROUND:

Improved risk assessment has been stressed as the way to reduce homicides by people with mental illness. The feasibility of predicting rare events needs examining.

AIMS:

To examine the findings of public inquiries into homicides by people with mental illness to see if they support the claim that better risk assessment would have averted the tragedy.

METHOD:

Analysis was made of the findings of the public inquiries between 1988 and 1997 in relation to the predictability and preventability of the homicides.

RESULTS:

Of the homicides considered by the inquiry panels, 27.5% were judged to have been predictable, 65% preventable and 60% of the patients had a long-term history containing violence or substantial risk factors for violence.

CONCLUSIONS:

Improved risk assessment has only a limited role in reducing homicides. More deaths could be prevented by improved mental health care irrespective of the risk of violence. If services become biased towards those assessed as high risk, then ethical concerns arise about the care of both violent and non-violent patients.