As a big fan of all the Law & Order shows in the US I hope the producers don't jump the shark by making an Americanised show in the form of Law & Order:UK.
Things to watch out for - there are NO cicadas in London except occasinally near the airports if they've come in on an international flight. THey quickly die in any event.
Sidewalks are called pavements here.
There are NO swirling FOGS in London. Occasional mists and only very close to water.
We don't "go do things" we "go AND do things"
The short 'a' is a phenomenon of the Northern accents. In London we have a long 'a' in normal speech.
NO ONE speaks like DICK VAN DYKE in Mary Poppins!!!
There is no 'traffic circle' adjacent to the Houses of Parliament (Re. National Lampoons). And if there was it would be called a ROUNDABOUT
What you call the subway we call the TUBE (or the Undergound) and what we call a subway you call an underpass.
London is possibly the most cosmopolitan city in the world (yes even more than New York) so find authentic actors for ethnic roles - we have enough of them to make it possible!
We call soccer football. Soccer is a correct term but here there is only one kind of football. That is soccer. So we call it football!
The point is you are going to need to research this. And make the show in London. It will never be possible to do it outside the UK if it's based in the City of London.
Please don't let us down!!!