Now we had a name. But running him through the system gave us no less than seventeen Sander Klaasens in the Netherlands, and a further two in the Dutch Antilles, none of which, after a gruelling process involving coordinating teams in several different provinces, was the one we were after. It was starting to feel like Klaasen was a ghost, or, at the very least, an assumed name. Which of course only made us even more keen to talk to him.

By getting Dankert, and five of the other people who’d been on the building site in Alkmaar that summer, to sit down with a police artist we came up with an image of his face which was widely circulated. And the next morning we got a result, a keen young officer in Haarlem spotted a man crossing the road who she thought resembled the image she’d been shown in her morning briefing. She got out of her car and approached him. He took one look at her and legged it. The chase lasted ten minutes, and she finally apprehended him, earning herself a nasty black eye and the respect of all. Hours later he was turned over to us for questioning.

He wasn’t fully convincing, giving only rambling stories which didn’t address our specific concerns, though he repeatedly denied killing anyone. Further background checks revealed nothing. That is, there was no record: of him being born, of being in school, being in care. Nothing. Hank and I pushed him hard, but he didn’t give us his real name. His DNA wasn’t on the system. I contacted mental health units up and down the country but no one recognized him. It’s like he’d come out of nowhere.

Even so, with no confession, all we had was circumstantial, and we were nervous about putting the case forward to the prosecutor. There were another seventy-two hours before I’d have to release him, at which point he’d probably disappear.