‘If you look here,’ he directs our attention to a patch of mud, ‘you will notice two different shoe prints. One set belongs to the victim, we’ve matched the print against the shoes he is wearing, and the other is…’

‘The same print as the one found on Anna’s face,’ I interrupt, finishing his sentence for him. ‘So it’s the same killer.’

‘It is certainly very similar, stylistically, to the murder at the rink,’ Martin agrees with a smile, before turning and marching back down the alleyway towards his team, leaving us to it.

Whilst waiting for John’s return, I take a walk around the surrounding area.

The grimy pub at the entrance of the street is a small, red brick building with dirty, stained glass windows. The type of place where, I imagine, fights are commonplace. A sign above the front door, swinging in the wind, shows two silhouetted swans with necks intertwined and a blackboard attached to the wall advertises a Thursday night quiz with a meagre prize as well as regular weekend karaoke sessions.

Around the back, there are three cars in the pub car park; reluctant revellers who started the night with the best intentions before succumbing to the lure of intoxication. At least they were responsible and took a taxi home, no doubt with the aim of returning to collect them today, once the hangovers have subsided. A light drizzle has started to fall, so I shield my eyes in order to look skyward.

There are two CCTV cameras visible; one above a window on the back wall of the pub, pointing at the car park, the other angled towards the mouth of the street. I take my notepad out and make a note of the cars’ number plates and to ask the pub owner for a copy of the CCTV tapes.

As I slip my pad back into the inside pocket of my coat, a silver Mondeo turns into the street and waits until the sentinel police officer holds the police tape high enough for him to pass under. It drives past us and turns into the pub’s car park and, once stationary, John emerges from the driver’s door. He spots Liam and me and raises his hand, before slamming the door and walking towards the alley.

‘Hello, you two,’ he says as we approach. ‘Brace yourself for this one, it’s quite a scene. Shall we?’ He ducks under the police tape securing the alley and we follow suit.

The narrow alley is only accessible from this end, the other blocked off by a brick wall so high you’d need a ladder to scale it. This means that the killer must have left via the main road once the deed was done, walking past the pub and emerging onto the street, which CCTV should’ve picked up. The floor has been tarmacked, though a forest of waist-high weeds have found the cracks that offer them a chance of life and have claimed the alley as their home.