It was another five minutes or so before Nash had pulled himself together enough to carry on with the interview. But it turned out that what he had to say was not what James was expecting to hear.

‘I could see Charlotte lying on the kitchen floor with the knife in her stomach,’ Nash said. ‘I panicked because I wasn’t convinced that Robert and Mary would take care of her. But when I pushed open the door from the room to the cellar, I was moving too fast and slipped on the top step. I went crashing to the bottom and smashed my head a couple of times.’

‘So, it was your blood we found on the steps,’ James said.

Nash nodded. ‘I didn’t realise how severe the blows were until I tried to get up off the floor and found I couldn’t. I was dizzy and disoriented and when I touched the back of my head there was blood on my hands. I think I may actually have passed out for a few minutes. But while I was lying there, I heard two loud bangs and assumed they were shots being fired.’

‘Are you telling us that you didn’t actually see who fired them?’ Abbott asked.

Nash shook his head. ‘I’m afraid not. By the time I was able to stagger out of the cellar and around to the front of the house it was all over.’

‘What did you do then?’ James asked.

‘The front door was unlocked, so I went in,’ Nash replied. ‘And I couldn’t believe what I saw. It was like a slaughterhouse with blood everywhere. It seemed obvious to me that Robert had shot his wife and then himself.’

Nash paused to blow his nose and dab at the tears that were streaming down his cheeks.

‘I went straight to Charlotte. She was lying on her back, her white blouse covered in blood from the knife wound,’ he explained in a voice that cracked with emotion.

‘Did you touch anything?’ James asked.

‘Only Charlotte’s face,’ Nash said. ‘I prayed that she’d respond even though I could see she was dead.’

‘So the bloody shoeprints belonged to you?’

‘That’s right. When I realised that I couldn’t help anyone I just got out of there as fast as I could. I didn’t think to check if I’d left any marks but I did throw my shoes away before I got home when I saw the blood on them.’

‘Why didn’t you come clean about all this before, Mr Nash?’ James asked. ‘You could have saved us all a lot of time and trouble.’