Of the 70 predictors examined, 26 showed statistical significance. Of these 26, the 10 that produced the 5 largest and 5 smallest values, i.e., the largest predictor variation between substance use and nonsubstance-use offenders, are the focus of this report. Substance users were more likely than nonusers to leave cigarette butts at the crime scene. They were also more likely to be identified or apprehended at the crime scene and to make attempts to gain entry to a number of potential targets until finding one with easy entry/access. Nonusers showed more planning for their thefts and the targeting of items for which there is a market for conversion to cash. Nonusers were also less likely than users to leave trace evidence at the crime scene. These findings support previous research that has shown substance use to have an effect on offender crime-scene behavior. The findings of such research can assist investigators in the identification of potential offenders. This may be particularly useful when an offender is committing a large number of offenses, leaving DNA or fingerprints, but are not in an offender database. Also, the crime-scene behavior may help identify individuals for whom police have up-to-date information on their substance use. Future research should explore links between substances, their physical/mental effects, and crime. More research is needed on the relationship between substance use and offense type, along with the effect particular patterns of substance use have on the recovery of forensic material from the crime scene. 8 tables, 1 figure, and 27 references