The clinical impact of structured risk assessment instruments has been limited by a lack of information regarding a) their short-term accuracy and b) the relationship between change as measured by the instrument and a change in the risk for harm. Data were collected every 4 weeks on a) variables designed to resemble the items of a structured risk assessment instrument, b) substance use, c) social circumstances and mental state, and d) violent behavior. Scores on the variables designed to resemble the items of a risk assessment instrument were associated with violence during the ensuing 4 weeks. However, an increase in a subject's score on these variables was not associated with violence. Instead, increasing cocaine use and increasing social conflict as described by the subject at interview were associated with violence during those weeks.