I'm not saying this doesn't happen.
But Blandshire Constabulary actually has a fiddle-fighting desperado to prevent these machinnations. She's called the SCRUTINEER, and her job is to learn the Home Office Counting Rules inside out and thoughtfully consider how best to follow them blindly regardless of the circumstances.
Any time a PC wishes to "no-crime" something (ie downgrade a crime report into a crime that hasn't happened), or to downgrade a crime from more serious to less, the Scrutineer will go over the crime report with a fine-tooth comb. Hence, I can attend an incident where someone has blatantly made up a robbery in order to claim double their benefit money, and spend the next three months arguing with the Scrutineer in my attempts to get this no-crimed.
Or imagine an incident where someone has claimed to have been stabbed, only when I arrive they refuse to show me the stab wound, show no signs of bleeding, and won't give a statement. It the "victim" refuses to provide a pocketbook signature confirming they were NOT stabbed, then not only will I be unable to no-crime this, I won't even be able to downgrade it from a Wounding to a Common Assault. Let's face it, the guy hasn't been stabbed. He said it to get the police there quicker, or because he panicked. But according to the statistics for that month, Blandshire has a knife crime problem.
I could talk about this for hours. Take Racism. As soon as the word "racist", "black", "country" or "Muslim" is mentioned, an incident becomes racist in the eyes of the Scrutineer. I attended an arson once where someone's car had been torched. The fire brigade told the police control room it might be racist, because a group of black kids was watching it burn, and the car belonged to a white guy. When I turned up, the white guy was amazed at this conclusion, and actually knew the black kids quite well and got on with them. But because the fire brigade had perceived it as racist, it remained and will remain racist forever.
All of the above makes Blandshire Constabulary excellent in the field of Recording Crime In Line With Home Office Rules. It makes us pretty rubbish in the field of Recording Crime in Line With Commonsense, and that of Actually Spending Time On Crimes People Care About.
So when the papers claim that forces are fiddling the figures to make them look better, I am fairly confident that Blandshire won't be one of those forces. We're actually fiddling the figures the other way.
'Diary of an On-Call Girl' is available in some bookstores and online.