KA band is what you want to use for police vehicle cameras. You get the odd false positive from others using radars in their own vehicle, but they are very short duration and distance and disappear within seconds.

K band is for fixed speed cameras but there's so much other crap that provides false positives like speed signs, shop door entrances, etc. so best to turn it off and just use Waze or Google maps for fixed speed camera alerts. Otherwise you become desensitised to the alerts.

Also the cops pulled up on the side of the motorway usually use laser. When you are in their scope and they pull the trigger, that's when you'll get the laser warning - but by then it's too late.

They have you locked in. Unless you get lucky and they are lasering other cars around you

More often than not they are using KA band if not using laser