Although there has been a wealth of research into the links between heroin use and crime in general, there has been an absence of research into the links between heroin, crack cocaine, and street crime. This study attempted to fill the gap in the research literature and examined the criminal career trajectories of heroin and crack cocaine users. First, the study sought to establish whether the heroin and crack cocaine use preceded participation in crime in general and street crime in particular or vice versa, and secondly, to establish offenders’ reasons for participating in crime and street crime, specifically to identify whether these reasons were drug-related. Results indicate there was not a direct causal relationship between heroin, crack cocaine use, and levels of participation in property-related acquisitive crimes. In addition, there was not a direct causal relationship found between heroin and crack cocaine use and participation in person-related acquisitive crimes. References