‘There is an interesting observation to make about his spatial behaviour too. In serial killers, we find that an offender will have a natural aversion to committing crimes too close to home, their buffer zone. And yet, conversely, they also have a comfort zone: a nearby area they know very well which isn’t too close to home and where they feel secure committing these acts. We refer to this as the Distance Decay Theory. It’s interesting to note that these victims were all from different towns and villages in this one part of the county, and their bodies too were all spread out in different locations in the comfort zone area. This leads me to believe that our killer lives in a different nearby location, one that hasn’t yet come up in the investigation, his untouched buffer zone.

‘As to his motive, I think what we have here is something that underpins a lot of serial killings: misogyny, essentially. This man has very strong feelings about women: he hates them. These victims are all attractive, educated, intelligent young women, and there is something there that this killer finds utterly intolerable. He sees these killings as his own personal mission. I find the wrapping of their heads in tape particularly interesting, like he is denying them even their own faces; cutting off their ability to speak or see before he kills them. These killings come down to power and humiliation, and the sadistic pleasure the offender takes from that. It’s likely the signs were there from a young age, and he started out by harming family pets as a boy. I would not be surprised if, somewhere in his possession, he keeps a manifesto with all his thoughts about women and how they should look or behave in order to be acceptable.

‘The police have not released any information about whether he stalks his victims beforehand, but I would say, given how meticulous the victim selection appears to be, that there is a degree of surveillance before he abducts them. I think that’s part of the thrill for him. He may even make direct contact with them, and it’s possible the killer has had intimate relationships with these victims.’

Outside Julia Hunter’s family home this evening, her eighteen-year-old sister, Harriet, stopped briefly to speak to reporters. When asked about the possibility of Julia being stalked before her death, a tearful Harriet had this to say: ‘I’m not sure. She never told me she was scared or anything. I would’ve helped her if she had. But she did mention a few weird things in the couple of weeks before. She talked about seeing some lines, chalk lines, I think, that looked like three stick figures, near the house. I never saw them and it was probably just our neighbour’s kids. Also, a couple of dead birds – pigeons – had been brought into the house through the cat flap. But Julia thought that was strange because our cat is very old now and hardly goes outside. She also mentioned getting a few prank calls. That was in the week before she went missing, but she didn’t seem frightened by them. If anything, she found them annoying. But [...] looking back on those few weeks before, everything seems weird to me now, now that she’s gone.’

A memorial service for Julia Hunter will be held on 21 February at her local church.

Ravi must have reached the end first, a sharp intake of breath right by her ear, like a windstorm trapped inside her head. Pip held up one finger to put him on pause, until she was done, reached the very last word.

And then: ‘Oh,’ she said.

Ravi jerked away from her, standing up to his full height. ‘Oh?’ he said, voice higher and scratchier than it should be. ‘Is that all you have to say about that? Oh?’

‘What are you...’ She spun her chair to watch him. His hands were dancing nervously, tucked under his chin. ‘What are you freaking out about?’

‘What are you not freaking out about?’ He tried not to raise his voice, but he should have tried harder. ‘A serial killer, Pip.’

‘Ravi.’ His name broke apart in her mouth, into a small laugh. His eyes flashed angrily at her. ‘This is from six and a half years ago. The DT Killer confessed. I’m pretty sure he pleaded guilty in court too. He’s been in prison all this time, and there were no more murders after his arrest. The DT Killer is gone.’

‘Yeah, well, what about the dead pigeons?’ Ravi said, his arm in a straight and quivering line, pointing back to the screen. ‘And the chalk lines, Pip? Those two exact things in the weeks before he killed Julia.’ Ravi dropped to his knees in front of her, holding one hand up to her face, thumb and little finger folded down. ‘Three,’ he hissed, bringing his three raised fingers even closer. ‘Three chalk stick figures. Julia was the fourth victim, Pip. Three before her. And now there have been five women killed, and there are five little stick figures out on your drive right fucking now.’

‘Look, calm down,’ she said, taking his raised hand, tucking it between her knees to hold it still. ‘I’ve never heard of those things Julia Hunter’s sister said there, not in any articles or podcasts. Maybe the police decided they weren’t relevant in the end.’

‘But they are relevant to you.’

‘I know, I know, I’m not saying that.’ She locked on to his eyes, tilted her chin. ‘Obviously there’s a connection, between what Harriet Hunter said and what’s happening to me. Well, I haven’t had any mysterious phone calls –’

‘Yet,’ Ravi cut across her, his hand trying to escape.

‘But the DT Killer is in prison. Look.’ She released his hand, and turned back to the laptop, typing DT Killer into a new search page and pressing enter.

‘Ah, Billy Karras, yes, that’s his name,’ she said, scrolling down the page of results to show Ravi. ‘See. Age thirty when he was arrested. He confessed in a police interview and – see – yep, he also pleaded guilty to all five murders. No need for a trial. He’s in prison and will be for the rest of his life.’

‘Doesn’t really look like the police sketch,’ Ravi sniffed, his hand finding its own way back between her knees.

‘Well, kind of.’ She squinted at Billy Karras’ mugshot. Greasy dark brown hair pushed back from his face, green eyes that almost jumped right out of his face, startled by the camera. ‘No one ever really does anyway.’

That seemed to help Ravi a little, putting a face to the name, the proof unrolling before his eyes as Pip clicked on to the second page of results.

She stopped, scrolled back up. Something had caught her eye. A number. A month.

‘What?’ Ravi asked her, a tremor in his hand that passed through to her.

‘Oh, it’s nothing,’ she said, shaking her head so he knew she meant it. ‘Nothing really. Just... I never realized before. The final victim of the DT Killer, Tara Yates, she was killed on the 20th April 2012.’

He looked at her, the same glint of recognition in his eyes, mirroring back her own. She watched herself, the warped version of her trapped in the darks of his eyes. Well, one of them had to say it out loud.

‘The same night Andie Bell died,’ she said.

‘That is weird,’ he said, dropping his gaze, and the Pip that lived in there slipped away. ‘This is all weird, all of it. OK, he’s in prison, but so why is someone doing the exact same to you as happened to Julia Hunter before she died? To all of the victims, potentially. And don’t tell me it’s a coincidence because that’s a lie: you don’t believe in coincidences.’