There is a few more relevant things on this topic. I could seriously get in bother for this, so it will probably disappear in a few hours.
The old system, prior to this month was mostly consensual searches, that is no specific police power was being used, the subject of the search "agreed" to it. There had been an interesting and relevant piece of case law that stated the subject of the search did not need to be told that he could refuse the search. Bizarre as that sounds it was pretty much legal to search whoever you like unless they were confident enough to refuse (very rare). There are a whole bunch of legislative powers we have to search, but we must have reasonable suspicion of an offence before using them. There is no power of search for alcohol.
Since the public scrutiny this has now been changed (as of this month), you must be told that you can refuse a consensual search. Taking drink off weans is not now a positive stop search.
He really, truly, believes that we can control people's behaviour. He thinks that the reason crime has dropped (despite any actual evidence of a link) is that we have been putting our hands in everybody's pockets. He is also obsessed with key performance indicators.
This resulted in a culture of mass stop search, driven by the local management. Why did they embrace it so much? Because the chief constable personally phoned them all to berate them over the phone about how shit they all were, and that they need more stop searches. What if they weren't on duty when he phoned? No problem, some got the call at their homes while with their families. You want to get promoted? get more stop searches.
So, you now have a scared area commander, he's not personally going to do any stop searches, so what's he going to do? He'll do what any ambitious manager with a lack of integrity would do, he'll bully the shit out of his subordinates. Meetings after meetings, being told that your shit, that this shift over here are doing it, why can't you? This is to the inspectors and the sergeants, never the front line cop, they can't be trusted not to speak to the press, must control the message!
Also relevant but not particularly sympathetic to the wider public, most of us want to be good at our jobs. Most police officers want to lock the bad guy up and stop people getting hurt. I don't enjoy being repeatedly told that I'm shit at my job. I like and respect my sergeant, who is now bullied and miserable. So what's the average, uniformed, street polis to do? Searches, lots of searches. Find someone near to a bottle of booze, positive stop search! What's the sergeant to do if the numbers aren't as good as they need to be, lie of course! So you find eight kids near to that bottle of booze? Eight positive stop searches!
You would think that it should all be about the positive stop search, but you would be wrong. A spreadsheet somewhere has its expected targets, and we must hit them. I have been in meetings where I have been told to go out and get negative stop searches, why that would ever be wanted is a fucking mystery to me.