This dissertation describes the life histories of 42 former left-wing Colombian guerrilla members of the M-19, ELP, and CRS. These reinserts' life course experiences are investigated using a descriptive, life course approach and a qualitative methodology.

These life courses are studied in the form of personal life course trajectories that are influenced by the individual (or his or her human agency) and by social circumstances (linked lives, locations in time and place, and timing of lives).

Three stages in the reinserts' life course involving the key transitions into and out of the movement are investigated. The first stage, acquiring a rebel identity, involves leaving civilian life and joining a guerrilla movement. Becoming a member of the insurgency is the first turning point in the reinserts' life course. The study identifies seven factors that influence the subjects' decision to enter these groups: (1) family, (2) peers, (3) conflict escalation, (4) generational imprint, (5) biographical availability, (6) individual ideology, and (7) desire to improve economic and social status in the community.

The second stage consists of reinserts' adoption and maintenance of their guerrilla identity. Four factors that influenced subjects' staying in the group were: (1) heavy dependence on the group, (2) shared values, (3) clandestine behaviors, and (4) the influence of the group on the subjects' self-identity. 

The third stage occurs when the subjects undergo the transformation from guerrilla to reinsert status. This involves first leaving the guerrilla movement and then abandoning the political party, AD-M19. This third stage involves a second turning point in the reinserts' life course where first military and then political activities are abandoned. Factors that influenced the subjects' decision to abandon political activities were: (1) the individual's perception that he or she did not matter to the group, (2) an increase in social obligations due to new roles in civilian society, (3) the stigma associated with being a reinsert, (4) political violence against reinserts, and (5) the stripping away of representative functions which had been carried out by the political party.