Peter had been twitchy when Jack and I visited him first thing this morning. We’d just turned up on the off-chance he would be in. He worked from home, he said. Something in software. He was obviously a keen runner as he was still in his Lycra when we got there, although he didn’t look as though he’d just been exercising: he was surprisingly fresh-faced with no hint of sweat. His wife, Holly, made us a cup of tea served in floral bone-china cups, then sat next to Peter on the sofa in their small, immaculate living room, too close so that her right side was pressed up against his left. There was an overpowering smell of plug-in air freshener in the room, but despite the bright furnishings the cottage was dark and a bit gloomy. It was the views of the beach and the sea beyond that were the selling point. Holly had seemed nervous, too, and didn’t want to go on record or give any quotes, even though she described to us the full horror of finding Deirdre Wilson slumped on the hallway floor.

‘There was so much blood,’ she said, shredding a tissue into her lap. ‘More than I thought there would be, not that I knew what to expect. Her eyes were wide and staring …’ She gulped. ‘I’ll never forget it.’

Peter placed his arm protectively around his wife’s shoulders. Then he explained to us that their house was the mirror opposite of Deirdre and Clive’s. ‘And as it’s a terrace I could hear every bang. I didn’t know they were shots. Obviously you don’t expect to hear gunshots, do you? That’s why it was such a shock to see that woman carrying a gun leaving their house. She acted like she didn’t care who saw her. I mean, she could have come in the middle of the night. Under darkness. You know?’

I’d sat and nodded as I took notes. I still found it hard to believe we were sitting there talking about Heather. And where had she been coming back from at six in the morning? Why had she not been at home, tucked up in bed with Adam? Or downstairs feeding her little boy? Had she spent the night somewhere else? With someone else?

The shootings had taken place around 6.45 a.m. So what had she been doing before that?