‘I always hate it when she’s on nights,’ he said. ‘It doesn’t feel right sleeping alone.’

The present tense he spoke in was hard to hear. What he had told them explained why the body had been found upstairs rather than in the living room or anywhere else. It also indicated Nigel Collins must have been watching the house to have known the woman would be vulnerable during the day.

Thinking about it from the killer’s point of view, Jessica could now see the pattern. Yvonne Christensen had been the easiest. She lived alone and slept at night like most people. If you could get into the house without alerting her, she would be fast asleep and provide no threat. Martin Prince was next in line because he was always on his own during the day but perhaps seen as more of a threat because he was a man? Claire Hogan would have been slightly harder to plan given that she lived on a main road and had a steady stream of visitors. And then there was Mary Keegan, who was the hardest. Had Nigel been watching and waiting long enough for her shift patterns to switch from earlies, to daytimes then back to nights again? If she was working similar hours to her husband, finding an opportunity to get either of them alone would have been a challenge. Nigel also didn’t seem too bothered whether he was targeting the father or mother, seemingly going for whoever was easier. He certainly must have kept an eye on the comings and goings over the past few weeks or months.

Jessica hadn’t done the checking herself but it had been established the doors and windows had been locked as with the previous three victims. The police officers had found Mary Keegan’s keys with her bag in the kitchen but the reasons were less clear.

Alibis would be checked for Paul, Scott and Steven Keegan – the only others with direct access to the house. Paul had given them the details of Scott and Steven’s real father too, Mary’s former husband, but said he was now remarried and living in Scotland. Everything would be looked at but Jessica knew it would be a formality. The man they needed to find was Nigel Collins. Tying him to the four murders could prove more of a problem, given the lack of obvious evidence at the scenes but Jessica figured they would cross that bridge when they got to it.

After she had asked all of her questions and heard everything that was likely to be useful, Jessica added, ‘Is there anything you would like to tell us?’

In interviews where the person had cooperated, it was always the last question you asked. In training, they had all been told a story of how a murder in the north east had been solved by a throwaway comment at the end of an interview. It was probably apocryphal, as so many of those training stories were, but the point had always resonated with Jessica.

Paul Keegan looked at her blankly and shook his head. ‘How do you mean?’

‘Sometimes when we interview victims and relatives, there are things they might remember that seem normal at the time but, in retrospect, could throw new light on something. People they’ve noticed and so on. Silent phone calls, things like that.’

‘We’ve had a few problems with kids over the last few months on the estate, riding their bikes and being loud late at night and so on. You phone the police but nothing really gets done.’

It was a story Jessica heard all too regularly. On the one hand she knew how much of a blight it could be on people’s lives but she was also aware the police couldn’t be everywhere. With a lack of funding and targets that needed to be hit, things like this were often treated as a low priority. Again, there was no irony lost on Jessica, considering how Mr Keegan’s stepson had seemingly behaved when he was younger.

‘I can only apologise for that, Mr Keegan,’ Jessica said. ‘Is there anything else?’

‘Not really, no.’ Jessica thanked him for his time then broke the news that they would have to arrest and speak to Scott. She reassured him his stepson was not suspected of any direct involvement to his mother’s death but couldn’t add any more than that. They were arranging for Scott and Steven to come back to the area. Steven would be interviewed informally at a later date in regards to the killing of his mother although he wasn’t a suspect. With the story breaking in the media tomorrow that their chief suspect was Nigel Collins, having Scott in custody would be a necessity. Even if the original assault case from almost six years ago wasn’t reopened, they couldn’t risk him running. He would obviously put two and two together but they would need to speak to him regardless – if only to formally rule him out of the inquiry into his mother’s death.

Jessica had already arranged for Jonathan Prince and James Christensen to be cautioned in relation to the unsolved assault all those years ago too. Things really were getting complicated, with Nigel Collins being both a victim and suspect in two different crimes.

Back in the main part of the station, Jessica could see the search for Nigel Collins was moving, albeit slowly. The original list of forty-seven names had been brought down to just three who were the right age. Two lived in the London area, while one was in a small town not too far from Nottingham. An officer was going to visit the Nigel Collins who lived in the town but dealing with the Met Police in London was always trickier. Their structure was even more confusing than Greater Manchester’s and there were always enough jobsworths to tell you that you were speaking to the wrong department. Anyone would think it was a different country they were trying to deal with. Eventually Aylesbury had become involved and two sets of two constables were now on their way to talk to the other two Nigel Collinses.

Jessica knew it was only a matter of time until they were ruled out. Whoever their killer was, it was someone who had been in the area very recently. Mary Keegan had been murdered that day but must have been watched for at least a few weeks previous. Their Nigel Collins wasn’t someone who drove up from Nottingham or London, walked through a wall and then travelled home again.

Door-to-door inquiries were being made in the hope anyone on the street had seen someone acting suspiciously. An accurate e-fit could be their only hope. The police did have a photograph on file from the original case but it was only the one of the poor kid’s battered face that had been on every news broadcast and in every newspaper at the time. It was no use for putting into a media campaign to find their prime suspect as you couldn’t tell if the victim was male or female, let alone make out any features.

The children’s home Nigel Collins had lived in didn’t exist any longer, having been bulldozed a few years ago. Cole had already set some officers on the task of tracking down some of the staff who would have been there at the same time as Nigel. Even if they got hold of the right people, it seemed unlikely they would stumble across a picture from his childhood they could use. At best it would be six years old but Jessica doubted they would get anything anyway.

That left them with a name of someone who seemingly didn’t exist, whose appearance they had no idea of and no idea how he got in and out of locked houses.

Nigel Collins really had set them quite a puzzle.

31

The next day was something Jessica had not been looking forward to. Every news bulletin on TV and radio had led off with the story that Nigel Collins was the ‘Houdini Strangler’. The only photograph the police had to give out was that of Nigel’s bruised face from almost six years previously, so it had been that staring out from the front of every newspaper, national and local, as well as the morning’s broadcasts.