Abel and his sister Haydee let revolutionaries like Fidel Castro use their tiny two-room apartment on the corner of O and 25th streets in Havana to plan the revolution. Abel and Haydee participated in the Moncada barracks assault in July 1953 that was supposed to start the revolution to overthrow Batista. After the failure in this action, they both were imprisoned with many other revolutionaries. Abel was murdered in prison after being tortured by police to reveal the location where the other revolutionaries were hiding. It's said that the police removed Abel's eyes and showed them to his sister Haydée Santamaría who was also in prison but she never revealed where the revolutionaries were.