The homicides all took place in 1984. Results revealed that in terms of lifetime use, marijuana was the most commonly used illicit drug in the sample. About one-third of the participants who had ever used marijuana used the drug in the 24-hour period before the homicide. Almost three-quarters of those participants said they were experiencing some type of effect from the drug when the homicide occurred. Eighteen participants (7 percent of the total sample) said that the homicide was related to their marijuana use; more than 80 percent of those participants said they were high on at least one other substance, usually alcohol, when they committed the homicide. Findings indicated that marijuana rarely had a determining role in the homicides. When it was a factor, it tended to have a secondary role. Findings cannot be generalized to all homicide offenders. Nevertheless, the results suggest that in-depth interviews of violent offenders has great potential for adding to knowledge of the ways and reasons why specific drugs may be related to violent behavior. Tables, author photographs and biographies, and 26 references (Author abstract modified)