‘Mixed messages,’ he said. ‘The destruction of her face looks frenzied. The bruising on her body is organised. You didn’t stamp on her at all, which you almost certainly would have done if you’d been in a frenzy. So, as with the facial destruction, in spite of appearances to the contrary, there’s a reason. Here, it’s because you are careful not to leave forensic traces. You’re determined not to be caught and you’re smart enough to have developed a strategy to deliver that result. You knew about the limitations of the CCTV coverage but still you took care to make sure you couldn’t be identified. The things we think we know about your appearance we may not know at all. You’re wearing glasses but they might have plain lenses. You’ve got a limp but you might be faking it. You look reasonably strapping but you could just be wearing bulky clothes on your upper torso. The only thing we will be able to say for sure, once some techie has done the biometrics, is how tall you are, give or take an inch.’

He pushed off from the wall and began pacing again. ‘So how do we use these contradictions to provide investigative value?’ He started numbering points on his fingers. Pinkie. ‘First, the victims resemble each other. Similar height and build, blonde, blue eyes, professional women, not in a relationship. As far as we know. You’re going for a type that means something to you. You want them to fit a specific niche in your picture of the universe. And when they don’t, you destroy their faces.’ Six, eight. Six, eight, brow furrowed in thought.

‘You destroy their faces because it turns out they don’t live up to the template. They look right but they don’t act right. So they don’t have the right to belong in that cohort any more. They’ve forfeited the right to be on the team. Let there be no mistake about it. They’re worthless. They’re history.’

Ring finger. ‘So it’s not a frenzied attack at all. It’s more in sorrow than in anger. And now the other stuff makes sense. You kick them to death to teach them a lesson. How dare they fail you? How dare they trick you into thinking they were the one and then not be the one? You’re sending a message, only there’s nobody there to read it. If only she knew it, you’re sending a message to the next one. “This is what will happen to you if you don’t pass muster.”’ He paused, frowning. ‘It’s savage, it’s lethal, but you never lose control, do you?’