A radar gun is a tool that police officers may use to determine how fast a vehicle is traveling. In some cases, it can be used as evidence that a car or truck was exceeding the speed limit. However, like any tool, it can provide inaccurate information, and it is possible to challenge a radar gun reading in court. An individual may assert that the device was not properly calibrated or tested.
Ideally, a radar gun will be calibrated after each use. Furthermore, the gun should be calibrated using the tuning fork to ensure that it is done correctly. If it is not done often enough or in the proper fashion, a driver could argue that any reading it produces is flawed. Drivers might obtain maintenance records to prove that a radar gun was not properly tested prior to being used in a given case.
In some cases, a police department will use speed guns that are based on Light Detection and Ranging technology. If a police officer uses a LIDAR speed gun, he or she may be required to be certified to use it. If a police officer was not certified to use it, a driver could argue that any reading that the gun obtained was not accurate because of user error.
Those who are charged with traffic violations could pay fine a fine or receive points on their driver's license if convicted. Challenging radar gun or other evidence used to issue a citation may result in the charge being reduced or dismissed. An attorney may review the case and help a driver obtain a favorable outcome in a case. This might be done by asserting that radar gun evidence was obtained incorrectly, which could result in the evidence being thrown out.