This chapter draws from two predominant criminological theories that have been used to explain desistance from crime: Life-course theories and theories of cognitive transformation. Particular attention is paid to life-course notions including aging out and acquiring new social roles. This chapter also addresses the nature of the homicide and the influence of imprisonment to help us understand how the homicide offenders on which this study was based, fare post-release. Did prison act as a school of crime, as a deterrent, or simply as a ‘deep freeze’, which implies that offenders came out the exact way they came in? Finally, the chapter discusses potential harmful effects of imprisonment, including institutionalization. This chapter serves as a theoretical background in coming to understand the ability of lifers to build a life for themselves before, during, and most importantly, after release.