‘Three days after this was taken the armoured vehicle he was travelling in hit an IED. He was blown clean out of it, suffered just cuts and bruises. The rest died underneath it, despite his frantic efforts to reach them. Two months later he was out of the Army, dishonourably discharged after attacking his CO with a knife.’

Woolf clicked onto the next picture. ‘Here he is that Christmas.’

Vestey was already looking the worse for wear: florid face, sunken cheeks and an air of defeat.

‘And by the following summer . . .’

He was almost unrecognizable in a police mug shot, eyes glazed and emaciated, in a filthy hoodie.

Woolf turned back to the group as the next photo appeared. ‘But here’s our same Mr Vestey just a few months ago.’

He was transformed, a slightly older version of the man he had been in Helmand, showing none of the scars of his trip to the dark side, in a sports jacket, white shirt and blue tie.

‘Quite a comeback, wouldn’t you say? Clean as a whistle, gainfully self-employed in VIP security, guarding the rich and famous.’

A man at the back raised a forefinger. ‘Membership of shooting clubs?’

Woolf grinned. ‘Aha. Since you ask . . .’ He hit the pad and up came a still of the gated entrance to what looked like a very well-defended hotel. To the side of the gate was a large sign in gold lettering – ‘Invicta’. ‘This organization should need no introduction. Since the post-Nine/Eleven wars it has become Britain’s foremost charity for ex-service personnel.’

Woolf flicked through a sequence, which showed an impressive campus of buildings surrounded by mature trees and rolling lawns, a lecture theatre, an Olympic-sized pool, an extensive gym and a golf course. ‘This is their HQ in Hampshire. Among the state-of-the-art facilities there does indeed happen to be a shooting range.’

The screen changed to another shot of Vestey, this time in Iraq, posing with his L115a3 sniper rifle.

‘Now, let me take you back to the early hours of June the twenty-eighth this year.’

A series of images from the Suleiman shooting flicked past, with blurred images of the police SCO19s, their faces hidden by their baseball caps. Then a full-face photo of Suleiman.

‘The target: a blameless community worker, widely respected for his campaign against drug-dealers and gangs. A devout Muslim but also an avid promoter of integration. Absolutely nothing to connect him with crime or terrorism. But whose killing apparently by the Metropolitan Police, despite their strenuous denials, brings the entire British Muslim community out on the streets in protest.’

Woolf paused to glance at Rafiq, who nodded his agreement. ‘And the rest, as they say, is history.’ He scrolled through a sequence showing the worst of the riots, looting even in ‘respectable’ areas, and more than one police van on fire. ‘The most widespread civil unrest in my lifetime, certainly. And no sign of its abating.