‘I’ve been expecting your call,’ Sonny said. ‘I know this situation isn’t ideal, Rachel. But until someone tells me otherwise, I’m SIO on this investigation.’

‘But you agree it makes sense for us to share information, right?’

‘Absolutely. I’m a hundred per cent with you in thinking the two cases are connected. And given you’ve got a four-day head start, it’s only going to help me if I can pick your brains about what you’ve got so far.’

‘Give me the name of your OIC,’ she said, using the common acronym for Officer In Charge of Case, the detective typically responsible for preparing the case file during an investigation. Rachel had already assigned this task to Ade in her team, and knew Sonny would have someone too, even at this early stage in his investigation. ‘I’ll speak to mine and ask her to contact yours.’

‘That would be really helpful,’ Sonny said. ‘Thanks. In the meantime, what can I do for you?’

‘An update on your investigation would be great,’ Rachel said.

‘Not much to tell you so far. Clodagh discovered the body at 4:45. The victim had been dead for at least five hours prior to that. Probable cause of death is stab wounds to the abdomen. She was stabbed twice. No sign of the weapon and we won’t know what sort of knife until the PM has been done. No concierge in the building. A dodgy CCTV means we’ve no way of tracking people going in and out of the building.’

‘Dodgy how?’ Rachel asked.

‘Dodgy as in broken,’ Sonny said. ‘It’s been down for a few days, apparently. The residents have reported it and an engineer has been booked to come out and fix it. But whenever that happens, it’ll be too late for us, I’m afraid.’

‘What about the intercom system?’ Rachel said, recalling the time she’d visited Tara’s apartment and shown Tara her warrant card through the intercom screen.

‘A basic system,’ Sonny said. ‘The cameras don’t record. But it’s a busy part of London. Plenty of CCTV in the surrounding area. I’ve got people going through all the footage, but you know how these things work. It could take us days to find anything. Our crime scene investigators found strands of hair on the victim’s clothing that are too long to be hers.’

‘Another woman then,’ Rachel said.

‘Most likely. We’ll have to wait to see what Forensics can tell us. Tara’s neighbour heard some sort of argument earlier that afternoon, but she wasn’t able to tell us who Tara was arguing with.’

They spoke for a few more minutes, but it was clear there was nothing else Sonny could tell Rachel for now. Promising to stay in touch, Rachel hung up and looked around the room, checking what her team was up to.