In 1961, Mesrine became involved with the Organisation armée secrète. He married Maria de la Soledad; they had three children but later separated in 1965. In 1962, Mesrine was sentenced to 18 months in prison for robbery (his first prison sentence, although he had been a professional criminal for a number of years). After being released, Mesrine made an effort to reform: he worked at an architectural design company where he constructed models, showing considerable ability. However, a downsizing in 1964 resulted in him being laid off. His family bought him the tenancy of a country restaurant, a role in which he was quite successful, but this arrangement ended after the owner paid a visit one evening to find Mesrine carousing with acquaintances from his past. The lure of easy money and women proved impossible for him to resist and he returned to crime. Overcoming some suspicion about his relatively middle-class background, Mesrine began to establish a reputation in the underworld as a man who was crossed at one's peril.