The incredible panoramic views of the River Thames, the South Bank and the London Eye did not make up for the impractical modern design of this ‘new’ New Scotland Yard, a relatively recent replacement for the far more workable, much larger New Scotland Yard that had now been sold and demolished to make way for more luxury residential homes.

It did not come close.

It was in this working area that Levy and Hale now sat, behind an empty desk in the team’s main workspace. Ahead of them were three tables, pulled together to sit end to end. All were piled high with case files. Four stacks per table. Twelve in all. How many cases per stack depended on file thickness. They varied wildly.

Six detectives sat between Levy, Hale and the files. Four men. Two women. All of them looked equally tired. It was not yet lunch, but for all of them it had already been a long day.

‘What was the filter?’ Levy asked, indicating the files. ‘How did you settle on these cases?’

‘We concentrated on crimes of extreme violence only.’ The reply came from one of the women. Detective Inspector Natasha Pickett. Ten years older than Levy. A talented but overstretched investigator, Pickett was no leader. Nonetheless she had earned Levy’s trust. ‘We just don’t have the manpower or the resources to review all of Longman’s cases. So we narrowed it down to those with defendants who have somehow shown themselves capable of the sort of violence that was done to him.’

Levy nodded. She was well used to working with limited resources; of the fifty officers who should have made up her MIT One, she had never had more than thirty at any one time. And that was just the easiest example of the underfunding that blighted every investigation.

It was for this reason that Levy had approved the plan to at first limit the investigation’s focus to Longman’s cases that featured ultra-violence. Such a focus would allow her to best deploy her limited manpower.

It had not worked as well as she had hoped; the large number of files still left was a disappointment.

‘There still seems a lot,’ Levy said. ‘How can we focus it further?’

‘We already have.’

This time one of the men answered. Detective Sergeant Pat Tucker. Another older officer, he was even more the stereotypical copper than Hale: tall, broad and carrying more than a little weight, he was an imposing figure on the streets. He continued.

‘We’ve removed completely every case where the defendant is dead or still in custody. That accounted for over half. These three tables are what’s left.’

Levy nodded again. She had hoped that the process would have narrowed the field more. Investigating the remaining files would still take thousands of man hours. Thousands of man hours she simply did not have.

‘Then we divided what was left into three categories,’ Tucker was still speaking. ‘One per table. The first table is for one-off offenders. Where violence is an anomaly on their record. The second table is for any offender released more than three years ago. On the basis that if they were looking for revenge they would be unlikely to wait so long, particularly with such an old victim who could easily have passed away in the meantime. And the third table is for cases of extreme violence, repeated offending and relatively recent release.’