The firms operating red light cameras and speed cameras in the District of Columbia and Maryland are working to suppress evidence that could be used to prove the innocence of a photo enforcement ticket recipient. In Washington, the Arizona-based vendor American Traffic Solutions has repositioned cameras and cropped photos so that it is impossible to determine whether another object or vehicle happens to be within the radar unit's field of view.
The change is important since DC hearing adjudicators have been throwing out citations whenever another vehicle was visible, creating the possibility of a spurious radar reading. The cropping also makes it extremely difficult to use pavement lines to perform a secondary check of the speed estimate provided by the radar. Lines painted on the road for this purpose are visible in one photo, but not the other (view first photo, view second photo). No video is provided to the vehicle owner.