There's different kinds of technology that may, or may not, be used; it's dependent on the department.
In general, the term 'radar gun' seems to be broad enough to fit all of these tools in. They point the radar gun at the vehicle, and the radar gun comes back with the speed of the vehicle. The police also have other methods, but they're not nearly as reliable, and, for the most part, are discouraged.
Most police officers I have met will show you the readings. As one officer stated, "It just shows the driver I have the proof".
There is no way they switched seats without the police noticing. Your son was speeding and blamed it on his friend.
Because white police officers don't see the need to have gang potection.
Most Ploice (85% or more ) in all states can tell if the insurance on a car is valid from inside the car.
Call the police and give an accurate as possible description of the vehicle (including license number if you can get it) and give the direction of travel. Speeding is a misdemeanor offense and an officer has to actually see it themselves before they can take any enforcement action.
The reason the word is inverted is because if a police car is coming up from behind a car, it can be as a stop or just speeding by, but since the word is inverted on the car when the driver of the car in front of the police car looks in their rearview mirror of their side mirror they can see the word inverted the right way. Since everything seen through a mirror is inverted, it makes it easier for citizen to spot police cars from behind.
The police officers have a computer system in their car to do that. The computer allows them to access the database to see people's license plate number.
See below link:
The Los Angeles, CA Police Dept. employs 9,937 police officers. For more information on the LAPD, see their official site on the link below.
Police want to know if you have a police record. Then they can look it up and see if you have a pattern of problems they need to be aware of.
See: http://en.wikipedia.org/wiki/The_Bill
See the related links below.