It was as narrow as Thermopylae in that hallway and Paul Warboys, a student of military history, was the Spartans. He was outnumbered and outgunned but fighting on ground that he had chosen. He had also chosen his weapon well. Civilians think that they can protect their homes and their family with a baseball bat. But you can’t swing a baseball bat in a confined space. The baseball bat is not a close quarters weapon.

You can swing a sap in a telephone booth.

‘Come on, come on,’ he said.

We had made the mistake of sending the uniforms in as our vanguard, half a dozen officers pouring past the shattered door the moment the scarred red battering ram brought it down. They all had their batons drawn but somehow the old gangster had the element of surprise. The sap came down again and again, delivering massive impact with minimum applied force.

Warboys grinned at me above the heads of the fallen officers.

I threw myself at him, seizing him in a bear hug, pinning his arms to his side before he had a chance to open my head with that sap. We slammed hard against one side of the hallway and then the other, glass breaking as we collided with a watercolour of the Thames, and I could smell his sweat and aftershave and I suddenly knew that he had been waiting for us all night long.

He cursed me, straining against the bear hug, he tried to sink his teeth into my ear.

Behind us, I could hear the cries of pain and threat.

‘You old bastard,’ I said into the side of his face, feeling his strength as he raged against me, my arms losing their grip. ‘If you’re an innocent man then why are you fighting?’

He laughed out loud.

‘Because you’re in my home,’ he said.

Then he threw me off and, as I bounced off the wall, aimed the black leather sap at the bridge of my nose.

I stumbled backwards, fell over a uniformed officer who was on his knees and felt the stubby black weapon slap hard against my bicep. In the broken doorway I could see the grey Kevlar body armour of the Authorised Firearms Officers, struggling to get inside, stepping over the fallen bodies.

I rolled away, a dull ache in the thick meat at the top of my arm, and Warboys raised the sap again as the AFOs came into the flat, only their eyes showing above their face masks and below their helmets, screaming their warnings – ‘Drop the weapon now! Drop the weapon now!’ – as they edged around the fallen officers, their assault rifles all aimed at the chest of Paul Warboys.