A radar detector suppresses alerts from vehicle guidance systems, by sweeping for a consistent radar signal; the center frequency of the signal is stored and the detector suppresses warnings of radar signals near that frequency. The detector uses an enhanced method for suppression of signals near a known location of a false signal source; in the event the detector detects a radar signal and finds a matching stored false signal, the detector will first compare the strength of the received signal to a threshold strength that is computed based upon the distance of the detector from the stored false signal, and will only suppress signals below threshold. The detector includes a camera directed to the road in the vicinity of the vehicle. Image data from the camera is processed to identify police vehicles as identified by flashing lights, a profile including a rooftop light bar and/or highly contrasting colored panels.