As a Washington, DC traffic violations lawyer, I can safely say that many drivers are not aware of all of the regulations in the District of Columbia. For example, unless posted otherwise, DC has a speed limit of 25mph. The police often set-up speed traps to catch drivers on the Calvert street bridge, the K street tunnel and other areas around the city. If you are caught going faster than 30mph above the posted speed limit, this is criminal speeding which is a Washington, DC misdemeanor where you are charged with a crime and have to go to court to defend yourself.
While it may seem hopeless if they have you on radar or laser (Lidar), there is often a lot that your attorney can do fight the charges. There have been many calibration issues with speed equipment and instances of officers not following proper procedure. Your attorney can file a motion to suppress where appropriate which may result in some or all of the charges being dropped. Whether this will work in your situation will depend of the specific facts involved. The important thing to remember is that you can’t beat the charges if you don’t fight. An arrest is not a conviction.