I can tell you this ,next town up rt23 from West Milford is Hardyston and they use K . Their favorite spot to set up is next door to the Ice Rink on rt23 south . The ice rink puts out a solid K signal , I would say the cops are aware of that and use it . Just saying.Most of the people I know who own radar detectors.. 1) have almost no idea how they work and 2) are the sub-$200, not-so-great-anyway variety.
If I'm the police, there is no way I'm going to all the trouble to try to select harder to detect radar equipment that blends in with the local door population when 99.9% of the speeders are oblivious and easy to catch if desired... I doubt that sort of thing is ever even thought about. They usually have tight budgets and their stuff is bought based mostly on cost, most of the time.