Three phones had been found among the victims’ belongings at the scene, all locked – an iPhone and a BlackBerry, apparently belonging to Tennent and Wilson, and a Samsung, presumably belonging to Kowalski. Hawkins had tasked Aaron with gaining access to all three.

‘One’s already done,’ Aaron offered. ‘The iPhone has fingerprint recognition, so I took it down to the morgue and used Tennent’s thumb. The techs are still working on the other two. They’re nearly there with the BlackBerry, but the Samsung has aftermarket security.’

‘When did you get access to the iPhone?’ Hawkins asked, irritated that she was finding out in passing.

‘Oh.’ Aaron realized his mistake. ‘Just now, really. Last half an hour or so. I was going to mention it.’

She let it go. ‘I assume you checked for any references to Brixton.’

‘Yes, ma’am. There’s no record of the flat’s address in contacts, search history or the phone’s navigational software. The techs are saying it would be easy enough to erase them if he wanted, though, so he could have wiped it, or known the address from before.’

‘Anything’s possible at this stage,’ Hawkins said. ‘Let me know as soon as we get the other phones unlocked, and start cross-referencing straight away. I want to know if any of them had common information, about the flat or anything else.’

Aaron agreed quickly, looking relieved that his turn was over.

‘OK.’ Hawkins’ gaze moved around the group. ‘Let’s forget about motivation and symbolism for a moment. It makes sense that the victims would have been restrained, and the restraints removed afterwards, otherwise the remaining two would surely have tried to run. But even if they went there willingly, people don’t just lie down and wait to be murdered. Which begs the question: how were they being controlled?’

Frank jumped in first. ‘I think it’s a gun.’

‘Or more than one person,’ Amala offered.

Chris spoke quietly: ‘Maybe they were being blackmailed.’

‘I think that illustrates that we don’t know,’ Hawkins summarized. ‘I agree that a weapon is the most likely method, but we’ve already questioned all the locals, and nobody remembers seeing anyone arrive at the flat or leave, armed or otherwise. It’s possible they might be too scared to speak up, I suppose – the estate isn’t what you’d call close-knit – but I would have expected someone to notice a four-person convoy, so we’re a way off being able to call that one.’ She glanced at Hunter. ‘More importantly, we need to establish why these particular three were killed. Were they random selections, or were they targeted?’

‘And why take the risk of killing all three at once?’ Amala asked. ‘Surely it would be easier to take them out one at a time.’