This study's principal focus was on the correlation that existed - if any – between heroin addiction and criminal behaviour. Previous research have reported addiction to this opiate to precede and provide the causation of criminal activity however, the opposite has also been observed, for criminality to lead to heroin abuse to the subculture that surrounds it. This study encompasses an independent samples design executed through a self-developed questionnaire. There were 82 participants, 51 male, and 31 female. These were taken from Pathways education centre for ex-prisoners and Addiction Response Crumlin for heroin addicts. The results strongly support the hypoFinal Year Project. Future proposals include additional rehabilitation programs and education outlets with relapse prevention, which will reduce the risk factors associated with heroin abuse and addict-related criminality.