As the front of the Coleherne was covered by a security camera, Ireland led Walker out of the pub by the side door, and they made their way back to Walker's flat in Battersea. With little preamble, Walker undressed and allowed himself to be bound, handcuffed and gagged (using knotted condoms). "I tied him up," Ireland later told police; "there was a four-poster bed... four posts with knobs on the top and I tied him by his fists with cord. Specially-made cord." Ireland had come equipped, prepared with a "murder kit": a knife, some cord, a pair of gloves, and a change of clothes. Having rendered his victim helpless, Ireland proceeded to beat Walker with his fists, with a dog lead and a belt. The post-mortem later suggested that Walker might still have believed it was a game at this stage, within the boundaries of his sexually exciting fantasy life. It wasn't to Ireland. "Once I had tied him up I knew my intentions were different to his. I'm not sure if I really set out to kill him... but it went from there."
After beating Walker, Ireland produced a plastic bag and placed it over his victim's head. He held it there for a time, taunting Walker, revelling in the God-like power he possessed: he could choose this man's destiny. "I took the bag away and told him how easy it was to end it all." Ireland told police:
"It was a fate thing and he said to me, 'I'm going to die' and I said 'yes, you are'. I think in a way he wanted to die. There was a lack of desire to carry on. I think he knew he was going to die... he was quite controlled about it. In the end I killed him with a plastic bag. I put it over his head and killed him with that."
When Walker was dead Ireland burnt his pubic hair. He was curious, he explained to police, how it would smell.
Meticulously, he then set about erasing all traces of himself from Walker's flat. An avid reader of true crime books and police - particularly FBI - manuals, Ireland knew that those criminals with some 'forensic awareness' would be more likely to get away with their crimes. He was a classic case of an organized killer: he wiped any surfaces he had touched with his bare hands, changed his clothes, and bagged the old ones, along with the cord he had used, to be disposed of later. Then, worried that he would attract too much attention by leaving at such a quiet hour, Ireland decided to stay until the morning. He watched some television and rummaged through Walker's personal effects.
Amongst these he came across some information that incensed him: Walker was HIV-positive and he had not told Ireland, although he was obviously planning sexual intimacy with him, and not disclosed his condition. John Nutting, for the prosecution at Ireland's trial, said that as an expression of his disgust Ireland "got some condoms and put one in his [Walker's] mouth and another in his nostril. As a further humiliation he put two teddy bears on the bed in a '69' position."
Before he left, Ireland remembers:
"I looked at myself in the mirror. Then I walked down the road and thought that anyone who looked at my face would be able to see I had just murdered somebody. I thought they must be able to tell by just looking at me. I remembered losing my virginity and I remembered the same feeling. You're always buzzing."
We recognize here that perverse association of sexuality and death that inevitably appears in the inner lives of serial killers, and eventually manifests itself in their behavior.
Inconspicuously mingling with the crowds, Ireland left in the morning rush hour to catch a train back to Southend. His crimes, he later told me, were committed in London rather than in Southend in order to confuse the police.
Recent research on serial killing, carried out at the Investigative Psychology Unit at Liverpool University, shows that serial killers have a "home range" which, according to Samantha Hodges, "allows us to say something about where the killer lives in relation to his crimes." This home range - the optimum distance that a killer will live from the crimes that he commits - is, in England, seven miles. Some 90 percent of killers live within this seven-mile area of operation. Knowing this, Ireland consciously decided to kill outside the defined range, in order that any profile drawn up of him would be inaccurate on this point, thus misleading the police. "I deliberately turned aspects of profiling," he told me, "attempting to use a tool of law and order against itself. The watchdog biting the handler." Another example of his attempt to baffle the police lay in his disposal of evidence: "My method of disposing of incriminating matter was to throw it from the return train window and always within the boundaries of the London transport network, my one exception made necessary by the presence of another passenger."
Walker's body was soon discovered, but the police had nothing to go on: Ireland had cleverly covered his tracks. He had always dreamed of committing the 'perfect murder', and it seemed he had done just that. The most obvious interpretation of the death was that Walker - a self-confessed homosexual with S&M inclinations - had been engaged in a sexual game, which had escalated out of control. However, when the police started their inquiries as to Walker's sexual partner for that evening, they immediately came upon resistance. The gay community is notoriously suspicious of the police, and unwilling to help an organisation they feel is hostile towards them and reluctant to take allegations of assault against gays seriously - one of the problems encountered in the Nilsen case. In addition, just the day after Walker's body was found, the Law Lords ruled that S&M between consenting adults was illegal. Thus, numerous gay men were unwilling to come forward to offer information lest they become the subject of prosecution themselves.
Two days after Walker's murder, the Samaritans received a call. A man told them that he was worried about Peter Walker's dogs. He had, he said, locked them in a room before he killed their owner. This eccentric behaviour ought not to be put down to the love of animals, and eager for publicity, Ireland didn't stop at one phone call. He then rang the Sun, telling them, "It was my New Year's resolution to kill a homosexual. He [Walker] was a homosexual and into kinky sex. You like that stuff, don't you?"