The first involved her rough sketch of the scene. In essence it was just a pencil drawing, but Kelly liked to make hers as detailed as possible; it might have to stand up in court one day. She’d drawn Ella Watson’s body where it fell, on the road through the park, and added the treeline, the training class and the pond and splash pool. Now she electronically added the direction Ella was running in, and the Beacon Estate.

‘We need to search this pond. No evidence of sexual assault; the timeline indicates there wouldn’t have been time, and her clothes didn’t appear tampered with. So motive seems to be pure and simple: murder. Estimated time of death, agreed on scene by the coroner and given by the witness testimony of the trainer, is 1.15 to 1.20 p.m. Blood flow was consistent with bleeding out, spatter consistent with high-velocity pressure spurting.’ She turned to her team. ‘So what does this mean?’

‘Surprise attack. Quick, passionless, violent and opportunistic.’ It was Emma Hide who spoke first.

‘I agree. Motive for murder?’

‘Someone ordered them to do it,’ Emma replied.

‘Precisely. Whoever did this didn’t do it for themselves, they did it for someone else. I’m talking to the husband as soon as he’s identified the body. Liaison officers will stay with the family as long as necessary. Mr Watson’s mother is on her way from Manchester to stay with them. We start there. Now, on to the photography and evidence lists. Very little, I’m afraid. Again, the speed of the attack makes our job that much harder. The coroner said they might have got away without any blood on them too, amazingly. Her wounds spurted in front of her and away to the side of the road. They were very likely behind her: this would explain the headphones being knocked off.’

She brought up the crime-scene photo of Ella lying on her side, her headphones a foot away in a pool of undisturbed blood. It was a singularly tragic scene. Ella Watson was about the same age as DS Umshaw, who also had teenage children.