One of the envelopes contained a collection of black-and-white photographs showing a woman getting into the passenger seat of a car. Or coming out – it was impossible to tell. Unfortunately, none of the pictures showed her face. When she wasn’t turned away from the camera, her hair was in the way, and as for the driver, it was too dark to see much more than that it was a man.

The car looked like a grey five-door Saab 9-3. But the registration plates weren’t visible in any of the pictures.

And then there were copies of various investigations. It wasn’t the first time he’d been through them, but it was the first time he’d taken the time to really dig into the details. He had decided to start with the oldest. It was by far the one he knew the least about.

The victim, Einar Stenson, was seventy-three years old when, on Saturday 21 April 2007, he passed away in his summer house by Ringsjöstrand in Hörby. Hörby was in the middle of Skåne, in the Southwestern Götaland Police District. Consequently, the investigation hadn’t been handled by Tuvesson and her team, but by a certain Ragnar Söderström in Eslöv, who had concluded it was a tragic accident that for a number of reasons had proved fatal.

According to the investigation, Einar Stenson had been alone in his summer house when he slipped on the newly waxed kitchen floor. He had fallen forward across the cutlery basket of his open dishwasher. The basket had contained, among other things, a kitchen knife pointing up, which had penetrated Stenson’s abdomen. A nose fracture and a laceration on his forehead suggested he had hit his head and passed out, which explained why he had bled to death.

It was undeniably a highly unusual accident, but at the same time completely plausible. A quick internet search revealed that Stenson was the only Swedish victim of such an accident. But in the UK, both a thirty-one-year-old woman and a six-year-old boy had died under what could be described as virtually identical circumstances.

The notes in the margin, however, indicated that Elvin had been very sceptical. He had, for example, highlighted the entire paragraph describing the kitchen floor as newly waxed and therefore very slippery, particularly since the victim had supposedly been wearing wooden clogs. The words newly waxed and clogs were circled and had question marks next to them.

But if the technical investigation was to be believed, the floor had, in fact, been waxed and in one of the pictures showing the victim slumped face down across the open dishwasher door, the left clog was still on his foot, while the right had fallen into the pool of blood on the floor.