Criminality of the mentally ill in sheltered care: are they more dangerous?

The sample of mental patients in sheltered care has a lower arrest rate than the general population in California in all categories of crimes, except for violent crimes. For violent crimes, the sheltered-care population is likely to be arrested at 1.33 times the rate of the state population, even when the heterogeneity of aggravated assault was taken into consideration. This indicates empirically that the mentally ill in sheltered care are more dangerous than the general population. For prediction of criminality, four factors are found to be significant predictors of resident criminality after 1973: (a) prior crime history, (b) age, (c) use of alcohol and drugs, and (d) sex (male). Among these factors, prior crime history is the single most powerful predictor of resident criminal activity. This is another confirmation of most of the previous research findings. Although there have been controversies over the issue of the dangerousness of the mentally ill, the results of this study, overall, support the most recent findings of studies in which the mentally ill population pose greater threats to the community than the general population. Now it is time to consider more specific and practical measures to monitor and carefully follow up the discharged population, especially those with prior crime history, and prevent further violent crimes. This will in turn help to promote the reintegration of the mentally ill in the community.