The painful privilege of policing is to see all of life – in all its vivid, unedited extremes.

And, after any length of time in this line of work, there might be a danger that you start to lose the capacity to be shocked; that having seen and heard so much, you somehow become immune to it all.

But that just can’t be so – and working life continues to throw up circumstances that leave you almost speechless.

A couple of years back – during my time as Southwark Borough Commander – local officers responded to allegations of a serious sexual assault on a teenage boy. He had been confronted by a suspect armed with a knife, demanding his mobile. On discovering that he had no phone, the assailant then forced him into the stairwell of a nearby block of flats. And raped him.

It happened in a public space…