I honestly don't know but I imagine guidance came from the Lord Chancellor. It was quite interesting to see that almost all cases involved in the riots were held in front of a District Judge rather than a bench of three magistrates.
There will always be situations that are exceptional where...
Police don't have influence in sentencing and if an individual police officer tried then one (or both) of two things would happen, they would be told, in no uncertain terms, to bugger off or would be reported, via channels, to a very senior officer.
It works like this: Parliament makes the law...