In 1986, 313 male Colorado inmates were surveyed in groups of 15 to 30 to obtain information on their behaviors during the 2 years they were on the street prior to their arrest for their current commitment crime. As in the three other study States, individual crime rates varied considerably among inmates and among crime types. On average, violent crimes were committed at a rate of fewer than two annually. Drug offenses were committed most often, with only 5 percent of the drug offenders reporting fewer than 2 offenses per year, suggesting that drug offending is a "lifestyle" crime. Violent offenses were committed at a much lower rate than other offenses among the most criminally active 10 percent of the sample. High-rate offenders were characterized by having participated in juvenile theft, having entered crime through friends and to get money for drugs, having been previously convicted for the same crime, having used drugs while on the street, and having been neither married nor living with a girlfriend while on the street. The report also discusses the quality of self-report data and the validity of the Seven Point Scale for the Colorado data. Appended study instrument, extensive tabular data, and 48-item bibliography.