If you are a fan of television crime drama, you can be left with a very false impression of what is involved in a murder enquiry.

Whether you watch the wholly improbable stories in Midsommer Murders or the more gritty realism of Vera in Northumberland, they all follow a similar pattern.

There is a murder. In the background we are aware of forensic teams and tests, but the focus is on the lead detective. They work it all out in their head. It’s just a question of how long before the penny drops.

Both Tom Barnaby – who has little help other than a hapless sergeant – and Vera Stanhope – who has a more realistically sized team – have light bulb moments when all becomes clear.

The episode then moves swiftly to its close as the suspect is arrested. End of story.

If only……

I have spent some time with some of the South Yorkshire detectives who are having to deal with a number of recent murders. Five murders in such a short period of time is almost unprecedented and has seriously stretched resources.

What is very clear to me, however, is that the really difficult work only begins at that point where television crime dramas generally end. This is where the evidence has to be brought together and the case made for the trial.

Hours and hours of long, hard work are involved. Pouring over cctv footage, social media and photographs; relating one to another; understanding the significance of what one is seeing – or not seeing; identifying and interviewing witnesses; getting statements; constructing time lines …. and so on. This is long and painstaking work.

You need your wits about you and there may be not one dramatic light bulb moment, but several, not just by the senior investigating officer, but by anyone who is looking at possible evidence.

And all this is done against a ticking clock because a suspect cannot be left in custody indefinitely.

Yet most of us remain in ignorance of all this work, which lies at the heart of any investigation. When I meet community groups and ask what they want of policing they never say they want to see more resources for investigations; just more visible policing.

The return of more visible, neighbourhood policing is important. We feel safer.

But we also need serious offenders successfully prosecuted and it’s the unseen work of the investigating teams that do that.