‘No. Like I said, this was the 1970s, so blood and DNA analysis was nothing like it is today. He was caught because he was a hired gun, not a carefully calculated killer. So although there were no bodies, there was evidence. The people who hired him, for starters, who had links to the people who disappeared. The police did their jobs and got to the truth through old-fashioned methods. Motives, circumstances, interviews and confessions. Like I said, you don’t always need a body to prove, in a legal sense, that someone has been killed.’

Dani digested those words for a moment. She felt slightly flummoxed by the story of Childs, because she’d been moving well away from the idea of her killer being a paid assassin working for gangs. Yet Childs had been just that. And Reeve had been involved in drugs.

Everything came down to the notes. Those notes. A gangland assassin wouldn’t send those. The notes had to be the clue to the killer’s motives… and identity.

‘What about other methods I mentioned then?’ Dani said. ‘Quick lime? Acid?’

Grant sighed as though a little bored by the conversation, like he’d had to cover these bases multiple times already. ‘Obviously I’m no chemist or biologist, but my understanding is that both could be used, to limited ends. Quick lime really wouldn’t be effective at all though. There are different types of lime for different precise purposes but in all cases if you bury a body in quick lime, or slaked lime or chlorinated lime, you may get some immediate or short term dissolving of tissue, but long term, given certain conditions, the lime can actually prevent putrefaction, which the killer really wouldn’t want. You’d effectively be mummifying the corpse.’

‘Seriously?’

‘Seriously. Don’t believe everything you see on TV, which I’m presuming is where you’re taking some of your knowledge.’

Dani felt offended by Grant’s words but she said nothing. It was true she’d never worked a case where a killer had gone to such lengths to dispose of a body and yes, she did take a lot of what she knew from fiction – TV, film, books.

‘Have you heard of Henry Wainwright?’ Grant asked.

‘No.’

‘In the late nineteenth century he killed his mistress, and packed her away in a sack of chlorinated lime which he stored in his Whitechapel workshop. A year later he was moving premises and so it came time to move that sack. His landlord saw him doing this and offered to help. During that process the sack somehow came open and the landlord caught a glimpse of a human hand and arm. He alerted the police, and Wainwright was caught. The body had been preserved so well that even a year after the poor woman’s murder, the police were able to prove her identity.’

‘Ok, so not lime then. What about acid?’