July 27, Roy appeared at the police station to confess to assaulting a 20-year-old woman in his apartment two days earlier. In October he pled guilty to this assault and was fined $200, plus the five weeks he had spent in jail. In 1989, suspicion again fell on Roy when a man arrested in Vancouver informed police that they should consider Roy a suspect in the murders of sex workers in that city earlier that year. Roy was never charged with those crimes, but the two Vancouver officers didn't forget the tip. In 1996, they gave their information to the Violent Crime Linkage Analysis System (ViCLAS) link analysis database and detectives in Toronto's homicide division picked up the file as part of a cold cases review. Reading over the initial police interview and other reports from Roy's parole officer, they were struck by inconsistencies and deceptions in the suspect's story. The division put a tail on Roy, who had returned to Toronto in 1991. The officers collected Roy's DNA from used cigarette butts and a coffee cup in Toronto bars and made a positive match with the DNA found on semen in Alison's body. Roy was arrested on July 31, 1996, just over a decade after Alison's murder. Trial The trial judge chose not to make certain evidence known to the jury citing a 1988 Supreme Court of Canada decision, as he feared this knowledge would prejudice the jury against the defendant and preclude his right to a fair trial. The withheld evidence included Roy's previous two convictions for rape, the fact that both rapes were committed on teenagers, and that one of the victims had been "tricked, abducted and bound, much like Alison". Defence Three witnesses testified that they had seen Alison in the company of a white man on the morning of her disappearance. The defence asserted that Roy was not intelligent enough to have committed the crime. Roy's only explanation for the DNA evidence – which matched his semen to that found in Alison's vagina – was that he had discovered Alison's naked body while looking for a place to urinate while on a run in the park. He claimed to have had a sudden urge to stick his finger inside her. Since he had masturbated earlier that day, he said, he still had semen on his fingers. Verdict After a month-long trial and six days of