Levy thought through the facts. It still did not feel right.

‘Are you sure he really qualifies for table one?’ she asked. ‘The offence might be a one-off but it was no crime of passion. It suggests a capacity for cold violence, surely?’

‘Maybe, ma’am,’ Pickett replied. ‘But it’s still manslaughter, not murder. There’s nothing to say he meant to kill the boy, which means we can’t actually guarantee a one-off capacity for murder. Plus there’s his prison record, which is what convinced me he belongs on table one. In a nutshell, he was an exemplary prisoner. No violence. No insubordination. Nothing. He made parole on the first attempt with the full support of prison staff and psychologists. Everything points to one-off violence.’

Levy nodded again, lost in her own thoughts. Whatever Pickett said, the crimes still worried her. They involved planned and calculated violence. But the other factors did meet the sift criteria. A one-off episode of violence against forty-six years of peace.

Plus three years of freedom, Levy thought. Pickett didn’t concentrate on that, but waiting three years for revenge? Against an old man who wasn’t exactly hard to reach? If anything, that’s the better argument against Hirst.

It was the final point that called it. Levy had her misgivings, but no system was perfect.

‘OK,’ Levy finally said. ‘Put him back where you found him.’

She turned to the second female officer. Detective Constable Sally Ryan. Twenty-nine years of age, Ryan was Levy’s rising star.

‘What do you have, Sally?’

‘Nicola Allan, ma’am. Two counts of murder. Her husband and his mistress. A nasty one, too. She followed them to the second victim’s home. Waited for the lights to go out. Then she broke in and stabbed them both to death in their bed. By all accounts it was a bloodbath.’

Hale interrupted.

‘Which table is this one?’

‘Table two, sir. There was a history of violence here. Nothing so extreme. But she had attacked another woman in the street six years before, using her high-heeled shoe as a weapon. Cut the victim’s face wide open, leaving a deep nine-inch scar. She was sentenced to eighteen months imprisonment for that. Plus there were incidents of attacks while in custody. So she doesn’t meet the criteria for table one.’

‘But she meets it for table two?’

‘And then some, sir. Longman was the trial judge. He gave Allan a life sentence with a minimum of eighteen years’ custody. Because of her behaviour inside – the violence against guards and prisoners – she ended up serving twenty-three. She was released aged fifty-two, and that was eleven years ago.’

‘So she could have taken whatever revenge it is she thinks she’s owed aged fifty-two, but waits until she’s sixty-three,’ Levy observed. ‘I think that makes table two a safe bet. And I doubt a woman in her sixties would be capable of physically lifting a body several feet off the floor and then crucifying him to a wall, no matter how old or frail he might have been.’