In 1947, in the course of an armed robbery committed by James Smith, Edward Hough, and David Almeida (defendants), police officers arrived at the scene and a gunfight ensued. A bullet struck and killed a bystander, but it was not clear whether one of the robbers or one of the police officers fired the fatal bullet. A jury convicted the robbers of the bystander's felony murder, after the judge instructed the jury that who fired the fatal shot was irrelevant. The judge told the jury to convict the robbers if they found that the armed robbery was the proximate cause of the bystander's death. Almeida appealed his conviction. In 1949, the Supreme Court of Pennsylvania approved the trial judge's instruction and affirmed Almeida's conviction. In 1966, Smith petitioned for habeas corpus on the grounds that the trial judge's instruction denied him due process. A lower court denied the petition, and Smith appealed to the Supreme Court of Pennsylvania, the composition of which had changed since 1949.