Robledo Puch was born in Buenos Aires on January 19, 1952, the date Argentine records give. He came from an ordinary middle-class family, which is part of why the case has never left the country's memory: he was twenty when arrested, blond and boyish, and the press settled on the name the Angel of Death.
Between March 1971 and February 1972 he and a childhood friend, Jorge Antonio Ibanez, robbed nightclubs, shops and houses. The first killings were at a club in Olivos, where he shot the owner and the night watchman while they slept. Seventeen robberies, eleven murders, one attempted murder, two kidnappings, sexual offences and two thefts were eventually proved against him. Ibanez died in a car crash before the arrest, which came on February 4, 1972. Argentine reporting called him el Angel de la Muerte, the Death Angel, and also the Unisex, after his appearance.
He was tried at San Isidro and convicted in November 1980, receiving reclusion perpetua por tiempo indeterminado, the heaviest penalty available in Argentina, which has no death sentence. The date of 1978 is wrong. He told the court it was a Roman circus and shouted that he would come out one day and kill them all.
He has been refused release repeatedly, most recently after a judge interviewed him in prison in June 2023. In 2013 he asked for his sentence to be reviewed and, failing that, to be executed by lethal injection, which does not exist in Argentine law; both requests were denied. He is held at Unidad 26 at Olmos and passed fifty years in custody in February 2022.
The repeated applications are possible because Argentine life imprisonment is not whole-life; release can be applied for and has been refused each time. He is the longest-serving prisoner in the country.