‘Passed right through the skull. Fair bit of damage to the bullet, obviously. I gather from Caroline it ended up in a tree.’

‘Anything on it?’

‘Yes, fortunately. Caroline took samples from where it penetrated the tree. The bark had traces of blood and bone, as did the bullet. I’ll run DNA tests but I’ll be surprised if it’s not a match for the victim.’

‘Any idea where the shot came from, Neil?’

‘Sorry, Clare, that’s Caroline’s area of expertise. But I can confirm the trajectory was upwards, as she suggested. It entered just below the temple on the left-hand side and emerged through the top of the skull.’

‘So our killer was below the victim?’

‘I’d say so.’

Clare ended the call and tried Caroline French’s number again. This time it rang out.

‘Hi Clare,’ Caroline said. ‘Chasing up your bullet?’

‘Yes please. Anything you can tell me?’

‘I think so. You probably know the bullet passed through the victim and lodged in a Scots pine beyond. It went far enough into the trunk for us to know the trajectory was upwards. The PM probably showed that too, yeah?’

‘It did.’

‘Okay. So we used a laser trajectory kit…’

‘Hold on,’ Clare said, ‘I want to put this on speaker so Chris can hear it.’

Caroline waited a few seconds then carried on. ‘We put rods into the entry hole then used the lasers to track back the bullet’s journey.’

‘How accurate can you be?’ Chris asked.

‘Pretty close,’ Caroline said. ‘Anything the bullet comes in contact with can cause it to deviate; but we looked at the entry and exit wounds on the PM report and compared them with the damage to the tree. I’d say it didn’t stray much from its original path.’

‘Which was?’ Clare waited.

‘Well, taking into account the likely distance and the angle, I’d say your gunman fired from one of the upper storeys of the house. Probably the top floor, although it’s hard to be precise about that. We didn’t find evidence of a second bullet so he must have been pretty close; either that or a really cracking shot.’

Clare thanked Caroline and ended the call.

‘So?’ Chris said.

‘We need to find out who, or what, was in that van.’

‘And the house?’

‘I want SOCO in all the rooms that face the treetop walk – top two storeys.’

‘Hold on, though. As soon as Russell Fox was missed those three men would have been all over the house looking for him…’

‘Compromising any evidence,’ Clare finished. ‘Yes, I know. But we’re only interested in the windows. And SOCO might find traces of gunshot residue.’ She stood thinking for a minute, then said, ‘Who’s running checks on the men?’

‘Janey and Bill from Dundee. They’ll be over in the morning.’