There hadn’t been any prints found on the murder weapon. The length of wood hadn’t matched any of the fittings in the building. The assumption was that it had been left over from a storage crate or something similar, but the identity of who had wielded it remained a mystery. Porter remembered Anderson mentioning the fire escape as a possible exit point for anyone who had been in the building, and wandered over to look. The door was locked, but he peered out of a nearby window and saw a fire escape angling downwards, hugging the side of the building. A narrow alley ran the length of the row of buildings and ended in a T-junction, one branch joining the main road they had parked on, the other a mirror image for the road layout that served the buildings behind them. It would have been a simple matter of exiting via the fire escape and taking the right fork, away from the oncoming police officers. Of course, the locked door would pose a problem, but for someone with a key, someone who owned the building, for example, it would be no issue at all.

Thanks to the chaos surrounding their first visit, they hadn’t made it up to the third floor to see where Carter had fallen from, and they headed there next. A series of large wooden boards had been fixed in place to plug the gap where the glass once was. There was a small heap of shards that caught the light. Not much to show for a window that size, but then again most of the glass had rained down after Carter and broken into even tinier pieces when it met the tarmac.

There was ample light coming through the remaining windows, and Porter noted the position of the desk underneath the light fitting. While Styles paced the edges of the room, Porter climbed up onto the desk and stood up. He looked over his shoulder, then up at the fitting.

‘I just don’t see it,’ he said, addressing no one in particular.

He thought back to the crime scene photographs and realised what had been niggling him. The position of the body had been such that Carter’s head had faced the direction that Simmons had approached from. If he had stumbled backwards off the desk and into the window, surely he would have fallen straight backwards and landed with his head and feet more or less at a right angle with the building, rather than at parallel to it?

Styles came over to peer out at the street through the remains of the shattered window. Porter dropped down to sit on the desk and repeated his concerns aloud for Styles to chip in his thoughts.