‘As to cause of death, we won’t know for sure that it wasn’t an overdose until we get the tox results, but Dr Sanders has made another observation which is interesting, although it’s little more than an idea at the moment. She has confirmed that the woman died of oxygen starvation – hypoxia – but how that happened is far from clear.’ Tom pointed to the whiteboard, where a close-up image of the woman’s neck was visible. ‘During the postmortem Dr Sanders found the marks you can see here. She believes they were made by something tied securely around our victim’s neck. She wasn’t strangled – the marks are far too faint for that and there is no damage to her throat – so our pathologist believes there is a possibility that a plastic bag was placed over her head and secured.’

DS Keith Sims, who had joined the team when Becky was on prolonged sick leave and had stayed ever since, raised a hand.

‘Yes, Keith,’ Tom said.

‘It’s my understanding that the build-up of carbon dioxide and lack of oxygen resulting from this type of suffocation induces a feeling of panic. Surely the victim would have attempted to rip the bag off her head?’

‘DS Sims is correct,’ Tom said, addressing the room. ‘But our victim doesn’t appear to have put up any fight at all, which could suggest that she had been drugged and was already asleep when the bag was placed over her head. However, Dr Sanders has another theory.’ Tom pointed to an image on the screen.

Becky peered at it, wondering what it could be. It showed a small depressed circle in the dirt-covered boards on the floor of the hide, as if something had been placed there.

‘This picture came from Dr Osoba, the crime-scene manager. He and Dr Sanders believe that her findings, together with this photograph and a very small piece of parcel tape found at the scene, suggest one way in which our victim may have died.’

Becky had no idea where this was going, but there was a briskness in Tom’s voice that confirmed she had been right about his expression. She leaned forward, all her attention focused on him.

‘We believe that death may have been via what is commonly called an exit bag.’ There was a murmur around the room and people shifted in their seats. ‘I called our newest team member, Lynsey, from the mortuary and asked her to find a suitable explanation for you. Over to you, Lynsey.’

Lynsey got to her feet and glanced at Becky, her eyes wide. Becky gave her an encouraging smile, and the young detective picked up her notes.