‘How do you mean? From the same supermarket?’ asked Erika, taking the bag from him.

‘No, these bags are manufactured to assist people to commit suicide. They are known as “suicide” bags or “exit” bags. I should have picked up on this with Gregory Munro. It was only when I saw it again with Jack Hart that I realised.’

‘So how does this help someone commit suicide? Why not just use an ordinary plastic bag?’

‘It’s very difficult to simply stick a bag over your head and wait to suffocate. We are primed with the instinct not to let ourselves suffocate. We call it the hypercapnic alarm response. As a person is deprived of oxygen, they tear the bag off in a panic. So someone came up with the idea of this suicide bag. As you can see, the bag is tall – it doesn’t fit snugly over the head, there's space above. The idea is that you place the bag over your head, and thread a plastic pipe under the drawstring before drawing it tight around the neck – but not too tight, as you pipe in an inert gas like helium or nitrogen. People have been known to buy the canisters of helium used to blow up balloons. They breathe the gas, which prevents the panic, the sense of suffocation and struggling, during unconsciousness.’

‘So the person who did this would have had to have bought this bag?’ asked Erika.

‘Yes.’

‘Where from?’

‘They can be bought online, from specialist websites, I believe,’ said Isaac.

‘So we could potentially get a list of people who’ve bought one of these bags?’ asked Erika.

‘That’s now up to you,’ said Isaac.

When they were finished, Isaac walked with Erika to the entrance of the morgue.

‘You should get some sleep. You look beat,’ said Erika.

‘I will.’ Isaac pressed the release button and the metal door opened. ‘Umm, I know that next week is the two-year anniversary of Mark’s…’

Erika stopped and turned.

‘Mark’s death,’ she said, holding his gaze.

‘Yes, Mark’s death. If you want to do something, I’m around. If you don’t, that’s fine too. We could go out, stay in. I just don’t want you to spend it on your own.’

She smiled. ‘I’m hoping that I’ll be solving this case. It will take my mind off it.’

‘Sure. Just know I’m here.’

‘Thanks. How are things with Stephen?’

Isaac looked guiltily at the floor. ‘Good. He’s moving in.’

Erika nodded.

‘Don’t judge me,’ he added.

‘I’m the last to judge,’ she said, holding up her hands. ‘I’ll see you soon.’ She gave him a grin and walked off down the long corridor.

38

Erika had called her team for an early morning briefing. She stood in front of the whiteboards with the crime scene photos of Gregory Munro and the new addition of Jack Hart. They were just settling down when Peterson arrived.

‘Peterson is back, and he’s brought decent coffee,’ said Moss, seeing him enter with a large tray of coffees.

‘Here you go, boss,’ said Peterson, offering Erika the large tray of Starbucks cups.

‘Where were you yesterday?’ she asked, taking a cup.

‘I had a dodgy Chinese,’ he said, not missing a beat.

‘Okay, well, I’m glad you’re back,’ she said, giving him a smile.

‘Thanks, boss,’ he said, looking relieved. He moved around the room, handing out coffee to the other officers.

‘So, this dodgy Chinese. Where did you meet her?’ asked Moss with a wicked grin, leaning up to take a cup from the rapidly emptying tray.

‘It was Kung Pao Chicken,’ Peterson said.

‘You got her name too! She sounds classy: double-barrelled.’

‘Piss off, Moss,’ he said laughing.

‘Okay. Right, let’s concentrate,’ said Erika. Everyone in the room settled down to listen. ‘So here we are again. We now have two murders, two weeks apart. Both victims live within the same fifteen-mile radius. I can confirm both were killed in exactly the same way: drugged and asphyxiated with a plastic bag.’

She paused as a murmur went around the room.

‘One was a regular family GP. The other was one of the most well-known faces on British television. So, as I always say, let’s go back to the beginning. And there are no stupid questions.’

‘They’re both male,’ said DC Warren.

‘Yes, we can see that from the crime scene photos,’ said Erika, pointing at the two men lying naked on their beds. ‘And?’