As the Fifth Doctor reported it, the First Doctor's granddaughter, Susan, struck up a friendship with Roberta Sampson. When the First Doctor discovered that Roberta was a werewolf, he warned her against her continued association with Susan, which angered and upset Roberta, who transformed into her lupine form. As she was now dangerous, the Doctor, who had come prepared for this eventuality, fired silver bullets at the werewolf in self-defence, hitting her in the shoulder and thigh. The Fifth Doctor said the death was likely due to a reaction to the silver, rather than the bullet wounds themselves, and that the First Doctor was not aiming to kill. (PROSE: The Juror's Story)
On one day of the trial, the First Doctor declared that he "had no choice". On this day, the foreman of the jury was Mr. Sutcliffe, which also included the Fifth Doctor (under the pseudonym of "Dr. Smith"), Dr. Harris, Mr. Asher, Mrs. Martin, Miss Mills, Mr. Eastman, Mr. Hopkins, Miss Nichol, Mr. McKee, Mrs. Preston, and Mrs. Taylor.
After the jury retired to discuss the verdict, the Fifth Doctor argued that the killing of Roberta Sampson by Dr Foreman had been in self-defence. While the other jurors expressed their doubt, he later backed up his claim with evidence presented at the trial, suggesting that it was proof that Sampson was a werewolf.
Without the other jurors knowing or noticing, the coming days saw several of the Jurors were replaced by further incarnations of the Doctor, including the Third Doctor (under the name of "Dr. Noble"), the Eighth Doctor (under the name of "Dr .Bowman"), and the Second Doctor (under the name of "Dr. Mason"). Each Doctor presented their logical arguments for the existence of werewolves, and evidence that werewolves were involved in this instance, with more and more jurists voting "not guilty" by each passing day.
The eventual verdict of the trial was "not guilty", and at its conclusion the First Doctor was rushed at by his granddaughter Susan, and the pair embraced. While leaving the building, the juror Dr. Harris became disorientated. The Eighth Doctor helped to steady him with a hand on his shoulder, saying:
This is the thing people just don't get about time travel - once you let yourself think, "Oh, it's all right, if it goes wrong I'll just hop back and fix it", you never stop and, before you know it, you've overwritten the timelines so many times they're all sort of falling to bits before your eyes.