Tandem,
That will be a very short conversation you will have about CAA and FAA regulated Police Operations as the FAA considers Police Ops to be "Public Use" and they have next to nothing to do with overseeing such operations. I reckon that would be an Apples and Oranges comparison and of not much use in wasting time on.
Would not a better question be one that argues about why you contract helicopter services and not have the Police operate the aircraft themselves?
New York City clear across to Los Angeles my country is populated with dozens and dozens of Police Helicopter Operations and almost all use Single Engined Helicopters exclusively for Day and Night flying.
I guess we hear all about how perfect the English system is compared to the Yanks but y'all go ahead on and try to convince us of that.