On December 29, 1985, Alison Day, aged 19, was dragged off a train at Hackney station and repeatedly raped by Duffy and Mulcahy. The victim was unable to identify him as the assailant, perhaps due to the traumatic stress she experienced during the crime. He was brought in for questioning and even participated in a photo line-up. Police thought the attacker’s description resembled Duffy. In September 1985, another vicious sexual assault occurred. His name was eventually added to the Operation Hart computer system as one of many thousands of local men who were being investigated as possible suspects. In August 1985, Duffy happened to be arrested after assaulting his wife. It was the largest multi-jurisdictional police investigation in the United Kingdom since the Yorkshire Ripper investigation was concluded successfully several years before. The police quickly set up a Task Force, calling it Operation Hart. In July 1985, three women were raped on the same night, all within a neighbourhood in North London. It was later discovered that most of the crimes occurred as close as a five-minute walk from Duffy's house. When investigators became convinced that two individuals appeared to be responsible for the violent sexual assaults that terrorized the citizens of London, the pair became known as the Railway Rapists. Most victims were teenage girls attacked while waiting for their train to arrive. Eighteen more attacks occurred, mainly at night, near various railway stations in the London area. The first sexual assault occurred in July 1982 when the yet to be identified Duffy and his accomplice attacked and raped a 23-year-old woman near a train station in a neighbourhood outside North London. They would be unable to establish sufficient proof until 1997, when Duffy admitted that David Mulcahy, a childhood friend, had been involved from the very beginning. It was first thought that he had committed these crimes by himself, but police eventually concluded that he had an accomplice. John Duffy was a violent rapist who embarked upon a four-year crime spree in 1982, attacking lone women near railway stations throughout various neighbourhoods in London, England.