Terán was born to Vicente Terán and Candelaria Salazar on April 9, 1941 in Cochabamba, Bolivia. His father, a merchant, was 46 years old when he was born; his mother was 45. Little beyond this is known about Terán's early life.
Military career and execution of Guevara
Terán joined the military sometime before 1967, at which time he was a sergeant in Company A of Bolivia's Manchego Regiment. Two years prior, Cuban President Fidel Castro had sent Che Guevara overseas to foment left-wing revolutions in other countries. At this time he dropped off the radar and his whereabouts remained unknown until early 1967. At that time, Bolivian communist youth organizer Loyola Guzmán received a tip locating him in a remote small town near the Paraguay border. Guevara reportedly told Guzmán that he hoped to turn Bolivia into a beachhead for socialist revolutions in neighboring countries. In March of that year, intermittent fighting broke out between Bolivian armed forces and a mysterious group of guerrilla fighters. Rumors that the group was led by Guevara soon began to spread, and once the Bolivian army leadership learned of this they determined themselves to capture him. Over the course of the summer, local officials provided tips that helped Bolivian armed forces narrow in on his position. Finally, on October 8, Guevara surrendered to Commander Gary Prado Salmón following a shootout with Bolivian soldiers. Upon arresting Guevara, Prado had planned to send him to be court martialed. However, Bolivian PresidentRené Barrientos ordered his execution the next day. At 11:30 that day, Terán walked into the schoolhouse room where Guevara was held prisoner and shot him dead with several shots of his M2 Carbine. Sources conflict on the precise details of the events of the executions, including how Teran was selected to perform the execution. Some sources state that Terán volunteered for the job. Other sources, including Guevara's brother, state that Terán had instead been chosen by his superiors and that he was reluctant to shoot Guevara. Sources also disagree on the number of shots fired, with some saying that Guevara was killed in two shots while others say that Terán fired at him nine times. After thirty years of military service, Terán retired as a senior warrant officer.
Later life
Terán now lives under an assumed name in Santa Cruz de la Sierra, Bolivia's largest city. He and his wife Julia Peralta Salas, whom he married in 1965, have six children two sons and four daughters. In 2007, numerous media outlets reported that Terán, under a false name, had received a free cataract removal operation performed by Cuban doctors as part of Operación Milagro. One of Terán's sons asked El Deber, a local Santa Cruz newspaper, to publish a notice thanking the doctors on Terán's behalf. After the Cuban government learned what had transpired, Granma, the official newspaper of the Cuban Communist Party, published an editorial using the event to promote Che Guevara's legacy, writing that "Four decades after Mario Teran attempted to destroy a dream and an idea, Che returns to win yet another battle, and continues on in the struggle." Terán's eye operation had become public knowledge only about a week before the 40th anniversary of Guevara's death. Some reports at the time, especially those from publications sympathetic to Cuba, additionally stated that Terán had been "virtually blind" before the procedure and that it had cured him of this blindness. However, in a 2014 interview with Spanish newspaperEl Mundo Terán disputed these reports. While acknowledging that Cuban doctors had removed cataracts from his eyes, he said that he had never been blind.
