The last couple of pictures were in the second rank, half hidden by the wife and kids. More men in kipper ties, sideburns, and embarrassingly wide lapels, photographed in a bar that looked familiar and which I suddenly recognized as the French House in Soho. I also realized I was looking at the young Alexander Smith, the nightclub owner, looking like a dandy even back then in a crushed-velvet smoking jacket and ruffled shirt.

“You didn’t happen to get any details about his career, did you?” I asked.

Trollope checked his notebook again but I knew even before he said it where the bulk of DCSI Johnson’s career had been spent: in and around Soho.

“He was CID at West End Central and before that he was in something called the OPS,” he said. I asked the dates and he said 1967 to 1975.

The OPS was the Obscene Publications Squad, the single most corrupt specialist unit of the most corrupt division of the Metropolitan Police. And Johnson had been a member during the most corrupt decade since London Thief Takers stopped being paid by the collar.

No wonder Alexander Smith was in the photograph. The OPS had run a protection racket for porno shops and strip clubs. You paid them so much cash a day and they made sure you didn’t get raided. Or if you did, they made sure you’d get lots of warning, so you had a comfortable and civilized interval in which to move all hard-core stuff somewhere else. As an added bonus you could bung the boys in blue a “drink” and they’d go around and raid your competitors and then sell their confiscated stock to you out of the back of the evidence room at Holborn nick. It also explained how Johnson could afford to take early retirement and probably why he had to take it.

Which made me look at the three remote controls casually left on the coffee table.

I squatted down by the TV stand. It was your typical gray laminated chipboard cheap piece of rubbish and quite difficult, because of the tangle of wires at the back, to clean the dust off effectively.

“Give me a hand over here, would you?” I asked Trollope and explained what I wanted him to do. Carefully, so as not to disrupt any forensic evidence, we both took a side of the DVD player and lifted it up. Underneath, there was a clear rectangle of light gray where something had protected the laminated surface from years of dust, something with a smaller footprint than the DVD player. I nodded and we gingerly put the player back down.

“What?” asked Trollope.

“He had a VHS player,” I said and pointed at the remotes on the coffee table. One for the TV, one for the DVD, and …

“Bugger,” said Trollope.

“You need to tell your scene of crime guys that somebody’s stripped this house of VHS tapes,” I said.