Inmate historical data are analyzed using prison computer records and ethnographic interviews. These two sources are compared, revealing strong discrepancies between the two datasets. Interview data yield significantly stronger correlations between early substance abuse and the onset of a pattern of juvenile criminal activity. Family history, analysis of offenses committed, issues of child custody, and parental alcoholism are investigated as factors contributing to chemical dependency and subsequent offense commission. Data reveal that all incarcerated Native Americans have or have had a chemical dependency problem, and that between 91 and 100 percent of all offenses committed by incarcerated Native Americans are alcohol or drug related. More alcohol-related criminal activity stems from the reservation, whereas more drug involvement is associated with urban dwellers. 9 tables, 5 notes, 43 references. (Author abstract modified)