The statutory inquiries after homicides by people with mental illness have been replaced by a system of mandatory reporting to the newly established National Patient Safety Agency (Department of Health, 2001a: p. 24). This reflects a radical change in the way that adverse events or ‘near misses' in medicine are to be investigated. Drawing on lessons from engineering on improving safety in aviation and the nuclear power industry, the Department of Health has moved from an individual to a system-centred approach. Whereas the traditional investigation generally stopped when human error was identified, the systems approach takes error as a symptom, not a cause, and asks why it happened, and what were the factors operating on the individual that contributed to the negative outcome (Department of Health, 2000). This approach to investigations could potentially lead to far more constructive solutions than those offered by the current system of inquiries after homicides.