There is probably no one in the world who would love to get pulled by a cop. And if you get pulled away, there are so many routine actions to be followed which make you furthermore nervous. Among all the routines, the most famous and loved routine followed by the cops is tapping your taillight of the car. Have you ever wondered why cops touch taillight?
The habit of cops touching the taillight is not new. In the olden days of policing the cops had the habit of touching the taillight as it had the benefit of inciting criminals before they could finish protecting their stash of ill-gotten goods. Is is very obvious that if someone is pulled over they would try to hide their guns or illicit drugs. Cops touched taillight way before the invention of dash cams and were super sneaky with their tactics.
One different interesting purpose why policemen touch back lights are because “it leaves a lot of evidence!”