‘Fergus Ariss’ doctor identified a pattern. He’d go through several months of increasingly serious and complex delusions, then at crisis point he’d disappear, only to reappear several months later back at the start of the cycle. There was also the unidentified corpse of a woman in the late stages of decomposition, clothed, no obvious wounds. We can’t tell yet how she died. They had to pull up more floorboards to get her out. The dress she was wearing matches other dresses found in a top-floor bedroom with a double bed.’

‘He’s taking women, dressing each the same way, then killing them?’

‘Which matches the concept of the pictures on the walls. He has a generic idea of a mother or a wife, how she should look, what she should wear, only something inevitably goes wrong, and then he needs to get rid of the … I don’t know … the faulty model and get himself a new one.’

‘He’s a serial killer.’ Baarda let that sink in for a moment. ‘So, how come he doesn’t conform to any established profiles?’

‘Because he’s unlike any serial killer ever profiled before. There’s a lot to unravel, but here’s the thing. Fergus knew he needed to change his name. He asked for a different doctor each time, producing fake documents to re-register. He just didn’t have the means to change his address.’

‘So as genuine and complex as the delusion is, he’s still functioning at some level that allows him to evade detection?’ Baarda asked.

‘Exactly. He may be delusional at times, but he’s also devious and manipulative. I believe the Advocate’s Close crime scene was the start of it. Abducting and killing the homeless, prostitutes or runaways was relatively low-risk. Anyone without a community to notice when they went missing. But those people didn’t meet his needs – his standards, if you like.

‘He kept starting the cycle over and over again, each time believing he was dying. Imagine how terrifying that must be for someone alone. Going through the trauma of believing that your body is rotting, and that no one can help or will even believe you. It’s a recurring nightmare. When he found Angela, although the risk was much higher, he felt she was what he needed.’

‘What for? I get that he wanted the family he never had, but how does that help him?’

Connie shrugged. ‘Maybe it’s as simple as wanting someone to mourn him after he’s gone, then when he realises he isn’t going to die, after all, he doesn’t need his fake family any more. Safer to kill them than to allow them to return to their lives and reveal his identity to the police.’

Baarda folded his arms. ‘What else was found in the crawl space?’

‘Just bones and the body. No weapons. No personal items,’ Connie said.