To properly expose an image, you play with the shutter speed (length of time the shutter is open to allow light on the sensor), aperture (a series of blades that make a circle of varying sizes which allow less or more light to the sensor) and the ISO (the sensitivity of the sensor).

In order to capture the image of something moving very fast, a quick shutter speed is required to reduce blur. Similarily, the aperture needs to be set to have a large depth of field, making the majority of the picture in focus in order to properly see the characters on a license plate. Thus, particularly at night, the ISO is increased to expose the image bright enough to read the plate, but the downfall is that this creates grain in the image, reducing it's quality.

Therefore, if you put a brighter light over your license plate than was originally intended, the setting on the camera will not be set correctly to give you a properly exposed image over the license plate, allowing you to dodge a ticket.

My idea stems from my understanding of camera mechanics due to being a filmmaker, and I can't imagine speeding camera's having a secret fourth setting that would cause any problems with my idea. Thoughts?