AMES, Iowa - News of a school shooting or a homicide involving a teenage suspect always leads to the question of why? It is human nature to want an explanation or someone to blame, and policymakers try to pinpoint a cause in an effort to prevent it from happening again. But too often, the speculation or rush to judgment clouds reality, said Matt DeLisi, a professor of sociology and criminal justice at Iowa State University.
"Anytime you have violence, such as a school shooting, people gravitate to single-item explanations that cite mental illness, guns, bullying or peer pressure," DeLisi said. "All of these factors likely have an influence, but there's really no silver bullet."
Instead, DeLisi and his colleagues at the University of Texas at Dallas found a handful of risk factors that are predictors, or distinguish homicide youth offenders from other serious offenders. Age was a factor, but those charged with murder also had a significantly lower IQ, higher exposure to violence, perceived that they lived in a violent or chaotic neighborhood, and were more likely to carry a gun. The study is published in the journal Youth Violence and Juvenile Justice.
Of the more than 1,300 serious youth offenders included in the study, only 18 were charged with some type of murder, which included attempted murder or involuntary manslaughter. Researchers examined 43 background factors associated with delinquency, such as psychopathy, prior arrests, family criminal history, substance abuse and gang activity.
The fact that there were more similarities than differences between homicide and non-homicide offenders is further evidence of the challenge to identify one predicting factor, DeLisi said. It also dispels some of the stereotypes. For example, offenders charged with murder were more psychopathic than other youth offenders, but the difference was not significant enough to make it a predictor of homicide.
"When you think about these youth offenders, who are very problematic and very delinquent, there are dozens and dozens of risk factors and lots of bad news," DeLisi said. "It's very hard to find those factors that are going to significantly predict which one of these youth will or won't commit a homicide."
Understanding risk factors
Of the five risk factors identified in the study, exposure to violence had the most significant difference between the two groups, DeLisi said. It is important to note that researchers looked at direct observational exposure to violence, not media violence or vicarious exposure. Offenders were asked whether they had ever witnessed a rape, shooting or an assault, and if they had ever been chased and thought they would be seriously hurt.
"The homicide offenders came from much more impoverished areas, with more violence day in and day out that they seem to be disengaged. When you observe that much violence it becomes very normal to you," DeLisi said. "It's really the worst of all worlds. They live in bad neighborhoods; have a lot of family dysfunction and family members who are involved in crime or who are victims of homicide."
DeLisi also pointed out that offenders with low IQ levels generally lack the verbal skills to effectively communicate or diffuse a situation. As a result, they may resort to violence. If you couple that with the fact that they are also more likely to carry a gun, it is easy to see how a situation can escalate to deadly violence, DeLisi said.
Less than 2 percent of youth offenders in the study were charged with some type of murder, which is a good thing, DeLisi said. However, a larger sample size could yield different results. Understanding the risk factors for youth offenders is important to preventing future violence. DeLisi said there are several studies that show people who commit murder are more likely to do it again. Still, there is no way to predict with 100 percent certainty which offenders will reoffend.
"It's very easy to predict the future in hindsight and it's impossible to do it otherwise," DeLisi said. "From a policy standpoint, that's why it's so difficult to decide who to keep locked up for a longer period of time. You may have a hunch that an offender might be more violent, but you don't always know."