[5] He married fellow militant Sônia Maria Morais Angel Jones,[4] who later died in the custody of the military dictatorship's political police.

According to political prisoner Alex Polari, who claimed to have witnessed the incident, Stuart was then tied to the back of a jeep with his mouth glued to the vehicle's exhaust pipe and dragged through the courtyard of the Air Force base, resulting in his death by asphyxiation and carbon monoxide poisoning.

[1][4] Based on Polari's letter and other evidence, Angel reported the murder to Ted Kennedy, who revealed the case during a speech at the United States Senate.

[4] According to Silva, among the reactions of the regime to the protests of the American-Brazilian community were the removal and subsequent retirement of Brigadier João Paulo Burnier, who Polari accused of being responsible for Stuart's death,[6] and the dismissal of then Minister of the Air Force, Márcio de Sousa Melo.

Guerra, who was director of the Department of Political and Social Order, known as DOPS, a department notorious for its practice of torture, extrajudicial killings and forced disappearance, pointed out to the Commission that Army Colonel Freddie Perdigão, an infamous torturer and state agent of repression, was startlingly present at the scene as the accident happened.

The photo had been taken on April 14, 1976, and was published by the press, but Perdigão's identity and significance were not connected to the case until Guerra identified him to the members of the Commission.

Stuart's probable death by asphyxiation and carbon monoxide poisoning was referred in the lyrics of the song "Cálice", written by Chico Buarque and Gilberto Gil.