The peak of the Tupamaros was in 1970 and 1971. During this period they made liberal use of their "People's Prison" () where they held those that they kidnapped. In 1971 over 100 imprisoned Tupamaros escaped the Punta Carretas prison. Nonetheless, the movement was hampered by a series of events including serious strategic gaffes and the betrayal of high-ranking Tupamaro Héctor Amodio Pérez, and the army's counteroffensive, which included the "Escuadrón de la Muerte" ("Death Squad"), police officers who were granted liberal repressive powers to deal with Tupamaros. Sendic was arrested in Uruguay on August 7, 1970, and remained in prison until his escape September 6, 1971. Sendic remained in Uruguay as a fugitive until his eventual capture one year later.