‘You should never feel embarrassed about the level of fitness you’re starting from,’ he was saying, his blue eyes fixed on the camera. ‘Most of my clients start out struggling to run at all, and I don’t worry about it. Fitness is for everyone and it’s my job to encourage and support you until you start to love it as much as I do. The trick isn’t to go at it hard and feel like a failure. It’s about making small gains. If that’s running for a hundred metres without stopping for the first time in years, then that’s a huge achievement, and I want to be there to celebrate that with you.’

Hanson continued watching and then loaded up a few more. Alex’s YouTube vlogging was miles from the narcissistic fitness clips she’d seen on her Facebook and Twitter feeds. He came across as warm, supportive and one hundred per cent genuine. With his Queen’s English, big blue eyes and chiselled cheekbones, he also came across as a little bit upper class. Where in other people it might have seemed obnoxious, Alex’s laughing apologies for his love of good wine and his trips to Lords were endearing.

She tried not to think about the fact that he would never upload another video, and scrolled down to look at what his viewers had written on some of the latest. She half expected to see tributes to him, but knew it was too soon. News of his death had not been officially announced.

Instead there were lots of profoundly grateful comments. Viewers told him how much weight they’d lost since starting his fitness plan. Others were clearly direct clients, referencing sessions with him and recipes he’d recommended.

And then, of course, this being the internet, there were other comments, too. The kind that made the human half of Hanson burn with anger, and the cop part sit up.

After fifteen minutes of scanning the abuse, Hanson felt in need of a gin. Or at least, she thought, a coffee. She slid her headphones off, but before she could move, the chief came over for an update. Lightman dived straight in.

‘We’ve checked for criminal records for the victim, his husband, and Louise and Niall Reakes. Nothing for any of them, and the husband seems fairly high-powered.’

‘Nothing linking the Reakeses to Alex?’ Sheens asked, looking between him and Hanson.