I was brought up, as all of my generation were, to believe that we had a three-tier class system in the UK: Upper class, Middle class and Lower or Working class. But ask any police officer today and he or she will tell you different, from grim experience.

I’ve spent much of the past two weeks with the Police, researching for my next Roy Grace novel, and getting updated on the latest changes – no police force ever stands still for long. Last Wednesday I was with the Met Police in London, on a drugs bust – or as it is more formally known, “Executing a drugs warrant.” The target was a Housing Association flat in an apartment block in a pleasant area of London where a middle aged mother lived with her teenage son and their dog. The son had had previous for drug dealing from this address.

It was to be a surprise raid. I was with eight police officers, all wearing helmets, visors and body armour, and we made a stealthy approach. Because on a previous raid at this same flat, the occupants fierce dog had bitten an officer, one carried a fire extinguisher to ward off the dog with if necessary. The police had a pass key to get in the outside front door of the block. Speed is essential once they try to get in the door of the flat itself, because otherwise the occupants, if they do have drugs, will flush them down the lavatory. So they smashed the door in with the bosher – the “big yellow key” as they call their battering ram, shouting loudly that they were Police officers. When we entered, there was an indescribable mix of vile smells. The boy’s mother waddled over and very huffily, holding back the hound, said, “You frightened my dog, he’s crapped.” She then bent down, picked up the turd in her hand, then waddled to the front door and threw it out into the communal hallway of the block. Then she wiped her hand on her dress.

If I tell you that her dress was the cleanest thing in that sizeable, two-bedroom flat, I promise I am not exaggerating. Every inch of the carpet was stained horribly. The walls were smeared with dirt and what looked like excrement – they were so badly smeared one police officer advised me not to let my coat brush against a wall. Every chair and sofa was covered in cigarette butts, ash, mouldy food particles, soiled clothing and empty drink cans. Tangled heaps of dirty clothes lay everywhere. Yet, of course, as in all such places, there was a 50” plasma TV screen on the living room wall, and 40” plasma screens in each bedroom. This was the kind of place where the police say, “You need to wipe your feet on the way out.”

The woman pointed angrily at her splintered door – not withstanding that the wood splinters were the cleanest thing on the floor, and said, “I’m going to have to get my Hoover out.” A woman police officer shot me a glance that said it all. Out of what? Out of its wrapping? Sadly, I have been to all too many places like this, and not just on drugs raids – but to domestic disputes, as well. Sometimes I’ll see a toddler crawling through the filth, soiled nappies tossed on the floor – but always that plasma screen, and usually a recent model car outside. There are levels of underclass in our society today that are not about money – but something else altogether.

I saw another element of sad life on Friday, when I spent the evening and night out on patrol in a response car in Crawley. The first call out was a Grade One responding to a call from a frightened girl who said her parents were fighting viciously. We arrived, this time not at a grotty flat, but at a pleasant modern terraced house. A couple in their late fifties had been going hammer and tongs at each other, culminating in the woman pushing her husband through a door window, badly cutting his back. And the cause of this dispute? They’d had an argument about their dinner. He wanted to barbecue (in February?) and she wanted to cook it in the oven. Fortunately the police officers attending had great common sense and enormous patience. They calmed the couple down, gave them warnings and left.

Later on that same night in Crawley we got a call that someone had just seen a group of youths break the wing mirror off a parked car. Having had a car vandalized myself once, and knowing not only the financial cost of having it fixed, but the massive inconvenience and the sheer anger it causes, it was a very pleasing experience that the police actually caught the “scrotes” responsible a very short while later, and they spent the night in custody. My evening climaxed with a call to a massive and vicious street fight outside a pub. Two victims already looked in bad shape. Over a dozen police officers were involved. Two people ended the night in hospital and eight in custody. Just a normal Friday night in Crawley – or any town in the UK. Upper class? Middle class? Working class? Nope. Half of the people the police have to deal with belong to something else, altogether.