Grant smiled again. ‘Dani, then. The debate over nature versus nurture is one that could go on ad infinitum. I’ve already discussed it at length several times this last week in fact.’

Dani raised an eyebrow but didn’t push Grant on what he meant by that.

‘Honestly,’ he said, ‘I’m not sure there is an answer, nor what you could gain from it if there was. That said, it is true that many well-known serial killers had experiences in their childhood that could be linked to their future destructive behaviour. Abuse, trauma, loss.’

‘But you don’t think that’s always the case?’

‘I’m not sure it matters what I think. Though I will say this: for starters, not all killers are caught and analysed. Those famous killers, the ones who the layman know – Fred West, Peter Sutcliffe, Jeffrey Dahmer – they get picked apart largely for the simple fact that it’s easy to do so. We know who they are, we know of their crimes. They were all over the media, they have movies and TV serials about them. Then, based on those cases, everyone begins to assume that all killers are the same. I’m sure you know the profile I’m talking about. Nut jobs who were abused as children, who hurt animals when they were kids before moving onto bigger prey as adults. You, for one, should know the answer isn’t as simple as that.’

Dani winced at the comment. Grant was certainly right there. Dani had gone through in her own mind thousands of times what it was that could have turned her brother into a killer. As a child, even as an adult, Ben had appeared about as normal as anyone else. The conclusion that Dani had come back to again and again was that there must have been something that changed him; that made him capable of killing without apparent remorse, though she’d never figured out what that something was.

‘I’m really not sure why this is important to you,’ Grant said. ‘Perhaps if you’re more specific then I can properly help you.’

‘I’ve dealt with murder for years,’ Dani said. ‘But those killers you mentioned before, they’re almost so extreme they’re not real world. The deaths I see are gang crime, domestics, drunken brawls, robberies gone wrong. But serial killers… I’d never really even thought about that. Until… my brother.’

‘In real life it’s best to assume that every conceivable connotation of good and evil is possible,’ Grant said. ‘First off, there are killers we know are out there, who just haven’t been caught. You must know what I mean by that? I’m sure you’ve known murder cases go cold. But there are also murderers out there who simply fly so low under the radar that we don’t even know of their existence. Serial killers do exist, Dani. They’re out there.’