The Police Officer used LIDAR or Laser to determine your speed.
A LIDAR device targeted your vehicle with a beam of light, or laser. It determined the speed by calculating the time that it took the laser beam to travel to your car, reflect off the bumper, and then return to device. The typical devices used in Fairfax and Northern Virginia are the Pro-Lite and the Pro-Laser III.
The Police Officer used RADAR to get your speed.
A RADAR device determined the speed by utilizing the "Doppler effect". Your vehicle was the fastest one encountered by the radio waves emitted by the radar, which caused a "tone" to signal the police officer that your car was speeding. Common radar guns used by Fairfax and Loudoun County are the Kustom electronics Golden Eagle, Golden Eagle Two, the Talon, and the KR-12.
The Police Officer paced your vehicle.
The officer followed you at the same PACE and got your speed by looking down at the speedometer in the police vehicle.
Because many of our clients have been stopped by law enforcement using these methods, The Gordon Law Firm acquired its own RADAR and LIDAR speed measuring devices and operating manuals. Our familiarity with the operation of the devices and with the requirements for calibration and testing of the equipment can help our clients during pre-trial negotiations with the prosecutor or at trial. By being prepared, we are able to present effective arguments in court concerning how RADAR or LIDAR devices may produce inaccurate results through computer or operator error.