Léopold Dion was tried in Quebec City in December 1963 as the accused killer of four children. The trial turned largely on one question: whether he was mentally ill or, as the Crown argued, an ordinary criminal who knew what he was doing. Nine years later, in 1972, he was killed inside the Sainte-Anne-des-Plaines penitentiary in Quebec, where he was serving a life sentence.
By the end of 1963 the Montreal daily Montréal-Matin was describing Dion as the alleged killer of four children. Press accounts from the 1970s describe the victims as four boys. The boys' names, their ages and the dates of their deaths have not been reported. Nor have Dion's own age, his work or his life before the arrest.
Dion's defense lawyer was Guy Bertrand. The defense told the court it would prove that Dion had been mentally ill for several years, and it called the psychiatrist Dr. Camille Laurin. According to Montréal-Matin, Laurin testified some days before December 11, 1963, that Dion had been mentally ill for at least ten years.
The Crown answered with its own psychiatrist, Dr. Paul Larivière. Testifying in Quebec City, Larivière told the court that Dion was a simple criminal and not a sick man, and that he should not be placed in a psychiatric institution. He described Dion as a man of below-average intelligence. In his view, the abnormal tendencies he had found did not make Dion insane: Dion could tell right from wrong, Larivière said, and knew that murder was both a sin and against the law. He added that he would not have committed Dion to an institution even if he had known of those tendencies earlier.
Bertrand's cross-examination grew heated. Montréal-Matin reported that he asked Larivière, angrily, whether the psychiatrist meant that Dion should be set free. Larivière did not answer. The newspaper headlined its report with the observation that the psychiatrists no longer agreed with each other.
The psychiatric evidence was still in dispute when that report ran; the jury's verdict, the date it was returned and the sentence that followed have not been reported.
By 1972 Dion was serving a life sentence. Le Petit Journal, the Montreal weekly, later reported that he was serving it when he died. When the sentence was imposed, and whether it replaced an earlier one, has not been reported.
Dion was killed in 1972 at the Sainte-Anne-des-Plaines penitentiary. Another inmate admitted killing him and was acquitted of murder by reason of insanity, Le Petit Journal reported in a feature about a memoir that inmate later published. The exact date of the death has not been reported, nor has any inquiry into how the killing happened.
His date of birth, his earlier record, the names and ages of the four boys, the dates of their deaths, the count on which he was tried, the verdict, any death sentence and its commutation, and the exact date of his death in 1972 have not been reported. The four killings were the accusation at his trial; which of them the jury ruled on was not reported.
December 1963 (some days before December 11): Defense psychiatrist Dr. Camille Laurin testifies in Quebec City that Dion has been mentally ill for at least ten years.
December 1963 (reported December 11): Crown psychiatrist Dr. Paul Larivière testifies that Dion is a criminal, not mentally ill, and knows right from wrong; defense lawyer Guy Bertrand cross-examines him.
1972: Dion, serving a life sentence, is killed at the Sainte-Anne-des-Plaines penitentiary; the inmate who admitted the killing is later acquitted by reason of insanity.