Explaining the increased arrest rate among mental patients: a cautionary note.

The author compared the annual arrest rates through 1978 of 301 state mental hospital patients released in 1972--1975 with arrest rates of the local county (San Mateo County) population in 1978. The data do not easily allow acceptance of the explanation for the increasing arrest rate among ex-patients suggesting that a definable group with previous arrests accounts for the increase. In San Mateo County, ex-patients with no previous arrests were arrested roughly three times more often than the local county population and five times more often for serious violent crimes.