Predicting Violent Behavior

Predictive Criteria

Certain criteria for determining future violence weigh more heavily than others. For example, it is well-known that the best predictor of future violence is a history of past violence. Based on this, it is important for the clinician conducting a risk assessment to obtain a detailed history of the client's criminal past, focusing on type of crime, degree of harm, and type of weapon used, if any. Such information should be corroborated by police reports when feasible.

Substance abuse is another strong correlate with violent behavior. A vast majority of violent crimes are committed while the perpetrator is under the influence of a substance. Van Hasselt and Hersen discussed three types of situations that link substances with violence. The first category is systemic, in which violence is related to activities associated with drugs (i.e., drug “territories”). The second category is economically driven, whereupon the individual engages in violent activities to support his or her addiction. Last, the psychopharmacological factor relates to the effect that the drug has on the individual. This final category has been well documented in the literature as a serious risk factor for violence.

The effect of alcohol appears to be one of the most lethal in that it is shown to commonly increase aggression as well as lower inhibitions. Approximately 60% of violent offenders are estimated to have consumed alcohol at the time of their offenses (Van Hasselt & Hersen, 2000). Other substances such as amphetamines, cocaine, LSD, and PCP can result in feelings of disinhibition and paranoia. Interestingly, men who use cocaine are “more likely to perpetrate violent crimes whereas women who regularly use cocaine are more likely to be victims of violence” (Scott & Resnick, 2002, p. 4).

Other demographic information that has been found valuable in predicting violence is age, gender, socioeconomic status, work history, military history, and intelligence. Violence tends to increase in the late teens and early 20s. The younger individuals are when they commit their first violent act, the more likely they are to continue that pattern during their 20s. Research has also found that men are 10 times more likely than women are to be the perpetrators of violence.

Individuals in lower socioeconomic areas are 3 times more likely to engage in violent behavior than people in moderate to high socioeconomic brackets. An individual's ability to maintain a job and the reasons for frequency in job change could provide valuable information into a person's tendency for violence. This helps identify whether the individual associates well with others and can follow job rules. People who are laid off from work are more likely to commit violent acts in comparison with their employed peers. In addition, an individual's military history, with attention placed on disciplinary measures and discharge classification, helps to give a greater picture of his or her propensity for possible violence and ability to follow rules.

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