He’d nodded absently, not really taking it in. He was too wrapped up in his study of the victims. It was after midnight when he finished his preliminary read through. He had a stack of paper with scribbled notes at his elbow. He would have to draw up a formal table relating all three cases to each other, but first he needed to know more about the academic specialities of the targets. He stood up and stretched, the muscles in his neck and back protesting at the sudden movement. Time for a change of scene.

He packed up his notes and let himself out of the flat. A short taxi ride brought him back to his apartment block. In the street, he glanced up at the third-floor windows. All was shrouded in darkness. If Carol was home, she was probably in bed. Their meeting could wait.

Upstairs, Tony ignored his still-packed bags and set up his laptop on the small writing table. He connected to the internet and navigated to the metasearch engine that he found most useful for tracking academic references. Within an hour, he had a reasonable overview of the research interests of Walter Neumann, Pieter de Groot and Margarethe Schilling. He scrolled back and forth through the material he’d downloaded, puzzled. He’d expected to find some glaring connection that would link the three dead psychologists. But their areas of specialism ranged from Margarethe’s interest in religious belief systems, de Groot’s studies of emotional abuse to Neumann’s work on the psychological dynamics of sadomasochism.

He went through to the kitchen and brewed himself a fresh pot of coffee while he ran through what he’d learned and compared it against what experience had taught him. Every serial offender had a mental profile of his victims. Usually, the common factors that linked them were purely physical. Whether the victims were all males, all females or a mix of the two, it was almost always possible to draw conclusions about the type he would go for. The elderly female victims of a certain kind of rapist; the vulnerable waifs who appealed to the sort of killer who had been abused himself as a child; the beautiful blondes who had to be wiped out because they would never look twice at the woeful inadequate who preyed on them. Even though the details of the offences could vary widely, the victims were usually as much a physical signature as the actions the offender took to make the crime uniquely his.