‘Well, we’ll hear about the negative breakthrough in a minute,’ Moore said, ‘but otherwise, you’re all up to speed on all four, aren’t you?’

‘We are,’ said Sam.

‘Then instead of each team, or a team representative, presenting their own, why not do each other’s? I promise you, when you listen to someone else talking about your investigation, however well informed they are, you’ll find yourself thinking, “They forgot X or Y”. Or sometimes they’ll pick up on things you mentioned in passing but didn’t spot as significant.’ Moore circulated an encouraging smile around the room – the facial expression equivalent of handing out copies of a useful pamphlet. ‘Shall we try it?’

‘I think it’s a very sensible approach,’ said Sam.

No one protested. Simon thought it might throw up some interesting results, though there was a parlour game aspect to the idea that made him want to reject it out of hand.

‘DC Woolston, do you want to start with Rhian, since she’s not yours?’ Kerensa Moore asked. ‘That way DC Wing can get us all up to speed sooner.’

‘Please, call me Grace.’ Woolston rose to her feet. ‘Rhian Douglas,’ she said. ‘Billy’s second victim. Twenty-three-year-old nursery worker. She’d worked at Little Chimps day creche in Poole, Dorset, for six years. Address 17 Nettle Edge, Poole. Rhian was shot in the back of the head on 21 October 2014, between 1 and 3 p.m., while her boyfriend Dolan Todd, a twenty-one-year-old car mechanic, was out at work at Green Fleet Cars, where he’s worked for two years. One neighbour, Samantha Granger of 19 Nettle Edge, might have heard the gunshot. Chances are she did, but she wasn’t sure because she was taking delivery of some shopping at the time, and she thought the loud noise she heard might have been the back of the supermarket’s van slamming shut, or another neighbour’s too-loud TV, a neighbour she’s currently involved in a legal noise dispute with.

‘The driver of the delivery van was subsequently found and interviewed, and he also remembers hearing a noise that sounded like a gunshot. He assumed it was a gun, but not a real one – he thought it was on the loud TV next door. I’ll come back to the deaf neighbour later.’

‘Oh, so will I,’ said James Wing ominously.

Grace Woolston said, ‘The evidence tells us nobody broke into Rhian’s house, so our working assumption is that Rhian invited her killer – Billy – into her home. She made him a cup of tea. Her body was found by her boyfriend on his return from work at 6.30 p.m. – she was on the floor close to the sink. The kettle was on the floor beside her. We’re thinking Billy might have said yes to a second cup of tea, then shot Rhian while she was standing at the sink filling the kettle.