We evaluated substance involvement among incarcerated juvenile offenders convicted of murder of manslaughter. Patterns of substance involvement among juvenile offenders were compared with patterns found in older offenders. Irrespective of age group, close to one-third of all homicide perpetrators reported that they were affected by alcohol prior to the offense. In every age group, alcohol was the substance showing the highest rate of "regular" lifetime use and the highest rate of ingestion in the week preceding the homicide. In many respects, the reported substance use patterns in the 16-17-year-old age group were closer to the patterns demonstrated by the oldest (36+) age group than they were to the adjacent 18-20-year-old group. Juvenile offenders were generally less substance involved than all but the oldest group of offenders. Almost all of the juveniles who were substance involved prior to the homicide attributed the homicide to the effects of those substances. Narrative accounts suggest that substances (almost always alcohol) escalated impulsive, spontaneous violent outbursts. Implications for the interpretation of self-reports about substance use provided by murderers are also discussed.