Nell looked around the room. The flat was situated above a betting shop in Rose Hill, the one Carla had flagged up and which Nell and Paul had visited the evening before. Had he been dead then? Lying here in his own blood while they talked crap to the shop owner?

She noted the tidy bedside table, a tube of moisturiser, a half-read book. ‘Who owns it? The flat?’

‘No you don’t,’ Paul stopped her. ‘You know the drill. You call the killer’s gender from the same information as I have. Just what’s in this room.’

It was a game they played. One of the little things that made the harder parts of the job more bearable.

Nell looked at the rose-coloured wallpaper – a little ripped at the edges – the chest of drawers on which stood a mirror and a brush, a book placed at an angle on the bedside table, and it occurred to her it looked just like a stage set.

‘I’m calling a woman.’

‘That’s a bold statement, Jackson.’ Paul’s tone told her what he thought of her conclusion but she just shrugged.

‘The room is bare, but what’s here suggests a female occupant.’ She looked at the hairbrush that’d be ripe with DNA to prove her right. ‘And attacking from behind suggests the need for surprise – to give the killer a chance.’

Paul looked unconvinced. ‘Yeah, but a man could just as well have needed surprise. Not all men have these.’ He flexed his tattooed biceps, thick from hours in the gym each night.

‘But why would a man be up here with him?’ She pointed to the bed, sheets ruffled. ‘I think whoever did it was here with him, then something happened to make her kill him. Maybe he got violent, she felt threatened, got what was nearest to her and hit him with it.’

‘But what? There’s nothing obviously missing, so what did “she” kill him with?’

He had a point. There was no obvious murder weapon, unless Eve had bagged it already. But if she hadn’t, if there wasn’t a murder weapon used in the heat of the moment, that would only indicate one thing.

Nell looked to Paul. ‘You think someone brought the murder weapon here deliberately?’

‘Maybe.’

‘Which would mean it was premeditated.’

‘Yup. And hours after his kid is killed? Too much of a coincidence?’

‘Kelly-Anne?’

‘She hasn’t been at the station long. She had ample time before to sneak out and meet him. Maybe they argued. She accused him of killing their child, they fought, she killed him.’

‘But that sounds premeditated. If the murder weapon was brought to the scene, she would have had to consciously choose an appropriate item, carry it on her, then be calm enough to take it away again after she’d killed her partner.’ And from what Nell had seen of Kelly-Anne, this seemed unlikely.