I ran across this one forum made for police officers....pretty big...and go into lots of detail about what they think about jammers...they all say they dont work in there first off....must have been running into rocky mountain radars then.... but it is pretty neat, you actually can find it by your state and see what activity is going on....lots of interesting news, and information cops have been running to while doing traffic stops:
General Law Enforcement Topics - Police Forums & Law Enforcement Forums @ Officer.com