‘Maybe Mark kicked the wall himself,’ Jason suggests. ‘We already know he’s got a temper. Although his mum reckons he’s a good kid underneath his fucking imbecile exterior.’

‘Don’t they all,’ Joe muses.

‘No sign of blood splatter on the walls,’ Isobel continues. ‘Annie is going through the shards of glass, but nothing there yet either.’

‘Any chance of DNA at all, do you think?’

‘I’ve found a couple of head hairs on one sofa cushion, but they’re likely to be Mark’s based on the photos that came back from the hospital. The packets of spice will obviously be removed, and we’ll send a sample batch for fingerprint analysis, so that might give us something.’

‘Any luck with the ligature?’

‘Possibly. There was an old tourniquet belt on the floor, which looked fairly consistent with the pattern of abrasions on Mark’s neck. That will go to the lab, and if we’re lucky, we might get DNA from the sweat or skin scrapings on there.’

‘Tourniquet belt? As in what nurses use to take blood?’ Jason asks.

‘Phlebotomists,’ Isobel corrects. ‘And yes. Except this one hasn’t been used by a medical professional in a while.’

‘Bit skanky?’

‘More likely to belong to a drug user,’ Isobel opts for.

‘Maybe it belonged to Jon and was just lying around here,’ Joe suggests. ‘Picked up in the heat of the moment.’

Isobel looks affronted. ‘I worked this scene the first time around, and we did a comprehensive sweep of the place. There’s no way we’d have missed something so relevant.’

‘How long were you here?’ Joe can’t help asking. He knows a suspected drug overdose of an NFA – a person of no fixed abode – wouldn’t be considered a priority.

‘We wouldn’t have missed it,’ Isobel repeats defensively, narrowing her eyes, reminding Joe that he shouldn’t make an enemy of her.

‘Of course, sorry. Any idea when the forensic report will come through?’ he asks, changing the subject.

‘Middle to end of next week maybe. How’s he doing by the way? The assault looked pretty nasty from the photographs.’

‘Lucky, apparently. Other than that, I’m waiting to hear from the hospital. Hopefully he’ll wake up soon.’

‘Yes,’ Isobel says with a sigh. ‘Did you say his mum is there? I bet she’s desperate.’

‘I meant for me. Much easier to find the assailant if you get it from the horse’s mouth.’

‘That’s if he knows anything,’ Isobel counters. ‘Looking at the scene, he may not have seen his assailant. There’s no electricity, so it will have been dark, except for the light coming in from the street. And the ligature mark shows that he was strangled from behind.’

‘You’re a bundle of joy, aren’t you?’

‘Just pointing out the facts, DC Stone.’