Katie stood looking at Billy Hagerty’s body for over a minute, saying nothing. Eventually, she said, ‘I don’t know whether this puts a whole new complexion on this shooting or not. Where do you think this surgery would have been done?’

‘Oh, in the UK, almost certainly. In Ireland there isn’t enough demand for gender reassignment surgery to set up a specialist treatment centre. There’s a scheme run by the Health Service Executive for sex-change treatment abroad. I think on average it costs something over thirty thousand euros for each operation… a bit more for female-to-male than the other way about. To put it blunt-like, it’s less expensive to cut off a penis than it is to make a new one.’

‘So it’s likely that the HSE paid for it?’

‘I would say so. He wasn’t the kind of fellow who could afford surgery like this out of his own pocket, was he?’

‘In that case, we should be able to access his records and find out when he had this done, and who he was before he decided to become Billy. I’ll go and talk to his brother, too – Donal.’

‘Oh… the one who murdered Michael Riordan and his family. I don’t envy you that.’

‘You’d be surprised. I interviewed him when he was first arrested, and he’s the mildest fellow you could ever hope to meet. A druggie, but not an aggressive druggie, more of a spaced-out druggie. It was hard to believe that he had shot a defenceless woman and two young children.’

Dr Kelley beckoned to Denis to bring over the sheet and cover up Billy Hagerty’s body.

‘I’ll be sending you my full post-mortem by the end of the day,’ she told Katie. ‘Obviously the cause of death was gunshot wounds to the head, but there’s some subsidiary results, too. His blood-alcohol level was on the high side, a hundred and ten milligrams, and there were traces of cocaine in his urine, although not enough to suggest that he was a chronic user. And of course his system was awash with androgenic hormones.’

They left the autopsy table and crossed over to Justice Quinn’s body. Denis lifted off the sheet for them, and there he was, a man made of black charcoal. Dr Kelley had split open his chest to carry out her post-mortem, and unlike most of the cadavers that she examined, she hadn’t been able to stitch him up again, so Katie could see his barbecued ribs. His right foot had broken off while he was being lifted from the burned-out shell of his car, and it was lying on the trolley next to him, still wearing its charred black shoe.

‘I was told you first identified him by a band that he was wearing.’

‘A claddagh band. I see you’ve removed it.’