To assess risks of violent offending in young adults, 425 Delinquent Assaulters (M age = 14.1 yr., SD= 1.7; 77 girls, 348 boys) were matched with 425 Nonviolent Delinquents. Analysis of data from court, school, and medical records used Shao's bootstrapped logistic regressions. Predictors of Assaulter status were poorer executive function (OR = 0.97) and prior court contacts for violent offenses (QR = 3.5e+ 23; AUC=.97; 95%CI=.82-.99). Looking in records backward 4 years (M = 4.1, SD = 2.6) and forward 10 years to mean age 24.5 yr. (SD = 2.1), adults were classified as Homicidal (8%, n = 69); Delinquent Assaulters Later Adult Assaulters (10%, n = 86); Delinquent Assaulters Later Noncriminals (32%, n = 270); Nonviolent Delinquents Later Nonviolent Criminals (10%, n = 87); and Nonviolent Delinquents Later Non-criminals (40%, n = 338). The Homicidal group (n = 69) was compared to matched Control and Nonviolent Delinquent groups (n = 69) using logistic regression. Predictors of Homicidal versus Control were poorer executive function and alcohol or substance abuse (AUC=.97; 95%CI =.93-.99). Predictors of Homicidal versus Nonviolent Delinquents were unemployment, poorer executive function, and prior court contacts (AUC=.98; 95%CI=.95-.99).