‘We’ll have to see if any of them had a night shift working.’

Petty ran a hand along the edge of the door frame. ‘I’ve lifted some good tool marks from the door. But it was probably just an ordinary crowbar or wrecking bar they used.’

‘Why does this door open outwards?’ asked Fry.

‘Ironically, because it’s a fire exit.’

‘And there was accelerant used in the store room?’

‘Yes, and two inner doors were forced open. By the way, I’d like to get the doors removed and taken to the lab.’

‘Why?’

‘Well, your offenders were in a hurry, so they didn’t bother to jemmy the inner doors – they just kicked them open. I’m pretty sure there are boot prints on the panels. But with the amount of fire damage, we’ll need lab facilities to get anything useful from them.’

‘You keep saying “they”,’ said Cooper. ‘What makes you think there was more than one person?’

Petty shrugged. ‘Well, there’s no direct evidence, unless we can get two separate boot prints from the doors. But they didn’t hang about here, you know. The fire service say they had a crew on the scene within ten minutes of the alarm. I’d say there were two people, possibly three. Two to break the doors open, while the third spread the petrol. Then they got out of the building quick, chucked in a match or a lighted rag, and left the scene. Apart from the one who wasn’t satisfied with what he’d achieved …’

‘You mean the hearse.’

‘Yes. That wasn’t really necessary. It looks like spite. It must have delayed their getaway by a couple of minutes.’

Without crossing the tape, Cooper moved to where he could see the compound and the scorched paintwork of the hearse. Curiously, only the front end of the vehicle had been damaged, leaving the rear compartment almost intact, though blackened inside by smoke.

‘What happened to the other vehicles?’ asked Fry. ‘There were several limousines in there, and another hearse, too.’

‘The staff were allowed to remove them,’ said Petty. ‘They had a funeral scheduled first thing this morning, so the uniforms let them get on with it. There was even a body in the fridge. That part of the building is undamaged, but the power’s off, so they could hardly leave the poor soul in there.’

‘I suppose it was the right decision,’ said Fry grudgingly. ‘Can we get inside, or are you still keeping the place to yourself?’

‘Just walk on the stepping plates and stay close to the wall.’

Cooper hung back as Fry went inside. He looked at Petty. ‘Sorry about Diane. She’s been like that ever since I came on duty. I don’t know what’s up with her.’

The SOCO began to strip off her gloves. Her face was flushed and glittering with rain. ‘I think I might know.’

‘Really? Has she talked to you?’

‘I can’t tell you, Ben.’ She looked at the window of the store room, protected by steel bars but with its glass shattered from the heat of the fire. ‘You’d better go, or you’ll be in trouble.’