An empirical theory of the development of homicide within individuals

There have been many attempts to explain violent behavior, identify its causes, and predict its occurrence among youth and adults. Research and theoretical constructions have dealt with such far-ranging aspects as childhood health, peer and parental interactions, neuropsychological function, school and community support, and substance use and dependency. Theories have tended to focus on one or a few of these aspects, but there is an effort by many researchers to converge on an integrated approach. By demonstrating unique risk patterns in random samples of later-homicidal abused infants, children, and youth, violent and homicidal delinquents, and homicidal adults, five studies by Zagar and colleagues provide the best current empirical evidence for a view of the development of delinquency as a process of accumulating risks. These risks begin with prenatal substance exposure and continue with abusive or neglectful parenting, academic failure, court contacts, compromised executive function and resultant poor social functioning. Analysis by sex shows that males' and females' risks are virtually identical. Various theories are evaluated with respect to these empirical risk patterns for development of violence and homicide. A proposal for the necessary elements of a successful, overarching explanatory theory is offered.