LIDAR Speed Detection

LIDARPro Laser III Lidar Gun

The speed in reckless driving cases is often determined by LIDAR.  LIDAR is an acronym for “Light Detection And Ranging.”  This equipment is increasingly common among both local police and state troopers in Virginia and frequently used to determine speed of vehicles for speeding and reckless driving charges. Officers will typically make a notation on the speeding or reckless driving ticket to indicate what method was used for speed detection.  For LIDAR, an officer will often write “LID” and may also make a notation regarding the distance between the LIDAR gun and the vehicle n questions.  Unlike Radar, which uses radio waves, LIDAR uses a beam of light which can be aimed at an object.

How LIDAR Works

First, the police officer takes aim at the desired vehicle with the LIDAR gun.  Officers are trained to aim at the license plate, as this is the most reflective part of a vehicle.  With one pull of the trigger, LIDAR will send out multiple laser pulses over a fraction of a second.  The pulses are reflected from the car back to the LIDAR gun, allowing the officer to get a speed reading of the vehicle.  This entire process takes approximately 1/250th of a second.

The laser pulses are degraded in a number of ways.  The most common are distance from the officer to the vehicle, refraction from differences in air density, if fired through the windshield of the police cruiser, from facing the sun, when aiming at a vehicle traveling toward the officer rather than away from the officer, and by ‘sweeping’ and getting a read from more than one vehicle.

The attorneys at Henson Pachuta, PLLC have found that the most commonly used LIDAR gun in Northern Virginia is the Pro Laser III manufactured and distributed by Kustom Signals, Inc.  Kustom Signals, Inc. is also often tasked with calibrating the LIDAR guns every six months.  Is it important to determine whether the officer used to LIDAR gun in accordance training by the department as well as with the operator’s manual that is issued along with Pro Laser III.

Reckless driving in Virginia is a class one misdemeanor. All crimes must be proved beyond a reasonable doubt by the government. Contact the attorneys at Henson Pachuta, PLLC for a free consultation by phone at 703-822-4701 or at 4011 Chain Bridge Road, Suite 200, Fairfax, Virginia.





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