responses to violence. Nevertheless, there are significant concerns with the validity, reliability, and accuracy of predictions of violence.
Some variables have consistently been shown to predict violent behavior. Other variables are strong in particular studies and often unmeasured in other studies. Variables that are commonly observed to predict violence, and variables that are predictive although infrequently used, provide guidance for conducting future prediction studies.
Family background variables appear to be valuable when predicting adult violence based on childhood records; they are of limited use in predicting repeated violence by adults. Criminal record variables are pertinent when predicting violent behavior within five years for offenders released from prison, but are of little use when predicting violence within a few weeks of release from a mental health clinic.
There is little doubt that criminal records (official or self-reported) are among the best predictors of violence, although there is some dispute about which aspects of criminal records have the greatest explanatory power. There is general agreement that violent offenders do not specialize in violence; nevertheless, past violence seems to be among the best predictors of future violence. There seems to be agreement that a propensity toward violence tends to be revealed prior to adulthood, but not all violent adults are known to be violent as children. There seems to be little doubt that drug involvement has some predictive power, although perhaps only for some forms of violence; the same may be true of alcohol consumption. Age, sex, and race are generally found to be predictive. Variables related to a child's development predict violence as a juvenile and as an adult. Variables such as family support can be useful when predicting violence. Although the nexus between violence and mental illness is nebulous, and it appears that health service professionals overpredict violence during clinical assessments, a history of hospitalizations has some predictive power as do some psychological scales that indicate a propensity toward violence. Violence during a period of hospitalization does not necessarily predict violence postrelease, however. The same is probably true of violence during periods of incarceration. Although the evidence from naturalistic settings is limited, biosocial variables seem to have strong predictive power.
Predictions are fairly accurate when violence during the short term is being predicted for a population whose past behaviors and current attitudes are well understood (e.g., people who