He returned to Brazil in 1970 as an infiltrator of the intelligence services and became an active member of the Vanguarda Popular Revolucionária (VPR, "Revolutionary People's Vanguard"), organization opposed to the dictatorship, in which he became responsible for the surrender and death of his own leftist comrades, as reflected in the episode that occurred on January 8, 1973, known as the Chacra de São Bento massacre. There, in the metropolitan region of Recife, six members of a VPR cell were tortured and murdered, among them Soledad Barrett Viedma, her young partner who, two days earlier, had turned 28 and was five months pregnant. Paraguayan and granddaughter of the Spanish anarchist writer Rafael Barrett, her case became famous when Mario Benedetti dedicated a poem to her and Daniel Viglietti a song.
