On May 26, 1963, a man with a camera persuaded thirteen-year-old Pierre Marquis to come with him and be photographed. He took the boy to a dune in the country outside Quebec City and asked him to pose naked. Pierre did, but when the man tried to assault him, he fought back, and the man strangled him. The dune was the same one where, a little more than a month earlier, the man had buried another boy. The next day Léopold Dion, forty-three, a convicted rapist out on parole, was arrested. Another boy he had approached had gotten away from him and given police his description.
Dion had been in and out of prison for most of his adult life. At seventeen he was sentenced to four months for gross indecency. In 1939 he was tried for attempted murder and acquitted. In 1940 he was convicted of raping a thirty-three-year-old schoolteacher in Pont-Rouge, the town whose name the press would later attach to him, and was sentenced to life in prison and a lashing. He was paroled in 1956, sent back in 1957 after another gross indecency conviction, and paroled again in 1962. In all he is said to have sexually abused twenty-one boys.
His method was a camera with no film in it. The first boy he killed was Guy Luckenuck, twelve, from Kénogami, who came into Quebec City every week for clarinet lessons at the Conservatoire de musique. Dion took a string of snapshots of him with the empty camera and suggested they carry on somewhere else, drove him into the country, strangled him and buried him.
On May 5 he met Alain Carrier, eight, and Michel Morel, ten, and used the same pitch to get them into his car. He drove them to a run-down building in Saint-Raymond-de-Portneuf. He tied up one of the boys by pretending they were playing prisoner, then led the other outside, told him to undress and strangled him with a garrote. He went back inside and smothered the boy he had tied up.
After his arrest Dion held out for a month before he described the killings in detail to his interrogators, and then he led investigators to the places where he had buried the children. For lack of evidence in the other cases, he was charged only with the murder of Pierre Marquis. He was defended by the criminal lawyer Guy Bertrand. On April 10, 1964, Judge Gérard Lacroix sentenced him to be hanged. Bertrand took the case to the Supreme Court of Canada and lost, and the sentence was then commuted to life imprisonment by the Governor General, Georges Vanier.
On November 17, 1972, Dion was stabbed to death in prison by another inmate, Normand Champagne, who was known inside as "Lawrence of Arabia." Champagne was already serving a life sentence for non-capital murder, and he was found not guilty of Dion's killing by reason of insanity.