Whether you’ve been pulled over by a cop or not, it’s pretty much common knowledge that it’s an unpleasant experience. Even if the cop you are dealing with happens to be extremely nice, it’s always scary and it will make you second guess yourself, even if you’re sure that you haven’t done anything wrong.
Before the cop gets out of the car and approaches your window, your mind is going a mile a minute wondering what you’ve done wrong so you may not notice that the cop touches your tail light before he walks to your window. If you have noticed it, have you ever wondered why they do this?
It has nothing to do with the cop wanting to touch your fancy car if that’s what you think. The cop probably doesn’t care what car you’re driving at all. It’s a precautionary move and it’s done for an important reason. So important in fact, that it can make every difference if the situation escalates and an investigation is required.
A cop will touch your taillights in order to leave fingerprints on it.
This is done to ensure that if anything does happen, they have proof.
So, the fingerprints function as evidence that your car was pulled over.
Cops are sometimes exposed to various dangers on the road.
If the driver they approach has done something reckless, they may possibly think that fleeing is a lesser risk than finding out what the cop has in store for them.
If they do decide to flee, the cop will attempt to identify the car. Once they do, the fingerprints will allow them to be certain that the car they’ve identified is the one that broke the law. In other words, it’s an investigative tool that will make any future investigation much easier.
The light tap is also meant to startle the driver in case they are attempting to hide any illicit substances or weapons. Instead, they’ll look up and see the officer approach their window. This “surprise tactic” has been responsible for the arrest of many drunk drivers, drug dealers and other kinds of criminals.
Of course, it can still be dangerous. When they touch the tail light, the driver may become desperate to escape and run off thereby injuring the cop. For this reason, the practice has been replaced with dash cam technology which allows cops to record the entire exchange without the added risk.