This study, using a longitudinal design, attempted to identify whether self-reported problems with violence were empirically associated with future violent behavior among Iraq and Afghanistan war veterans and whether and how collateral informant interviews enhanced the risk assessment process. Data were gathered from N = 300 participants (n = 150 dyads of Iraq and Afghanistan war veterans and family/friends). The veterans completed baseline and follow-up interviews 3 years later on average, and family/friends provided collateral data on dependent measures at follow-up. Analyses showed that aggression toward others at follow-up was associated with younger age, posttraumatic stress disorder, combat exposure, and a history of having witnessed parental violence growing up. Self-reported problems controlling violence at baseline had robust statistical power in predicting aggression toward others at follow-up. Collateral report enhanced detection of dependent variables: 20% of cases positive for violence toward others would have been missed relying only on self-report. The results identify a subset of Iraq and Afghanistan war veterans at higher risk for problematic postdeployment adjustment and indicate that the veterans' self-report of violence was useful in predicting future aggression. Underreporting of violence was not evidenced by most veterans but could be improved upon by obtaining collateral information
