Official and self-report criminal history data were used from a pretrial services unit at a large adult county jail in Colorado. Official data included national, State, and local records that measured all of the respondents' recorded criminal history. Self-reported criminal histories were taken from official bond interviews between the pretrial services unit and arrestee-respondents. Interviews were conducted from January through September of 1998. Two independent simple-random samples yielded 100 homeless respondents and 100 domiciled respondents. This sample size (n=200) was selected because it was sufficiently large to portray the parameters of the total criminal offender population. Six demographic and six criminal history variables were used. Findings show that homeless jail inmates were significantly more likely than domiciled jail inmates to be mentally ill; to be arrested for nuisance offenses; to have more extensive criminal histories; and to have prior arrests for use of weapons, drugs, and alcohol. Criminal justice practitioners could benefit from this epidemiological information by channeling specific elements of the homeless population to the most appropriate resources: substance abuse care facilities, mental health facilities, detoxification centers, homeless shelters, and jails. 3 tables and 16 references