Let’s face it: Most of us who drive don’t make it our entire lives without being pulled over by a cop at least once or twice. If you weren’t too busy frantically searching for your license and registration, then you may have noticed that sometimes, the cop taps your tail light before approaching your window. Have you ever stopped to think about the reason why they do this? Well, turns out there are a few.

Why Police Officers Tap Your Tail Light When They Pull You Over
If you have been driving for a while or you’ve been pulled over by an older officer, you may have noticed that they tap your tail light on their way to your window. Though the practice is becoming less and less common now, the reasons why they do this are as smart as they are practical. This is why they do and also why it isn’t as common as it once was. (1)

1. To Learn About The Driver
There is an inherent danger in pulling someone over for a cop. They don’t know who the person is, how they are going to react, and what they have or haven’t been doing prior to that moment. Tapping the tail light helps them learn about the driver’s mental state. (2)

Did the tap startle the driver or were they distracted by something else and didn’t notice?
Are they under the influence?
Are they hiding or attempting to hide something (weapon, bottle, drugs, etc)
Having even just a bit of an inkling of who is sitting in the driver’s seat and in what state they are could save an officer’s life.

2. To Leave Evidence
When the officer touches your tail light, they leave their fingerprints on the car. This leaves behind evidence that they were there, so if something bad happens investigators will be able to identify that they were at the scene. This reason isn’t as necessary any more thanks to dash cams, GPS tracking, etc.

3. To Check The Trunk
If there is someone in the trunk, tapping the tail light is one way to potentially determine it. This is both for the safety of the officer, in case someone will pop and harm them, and for the safety of the person who might be captured in the trunk. Usually, if the cops suspect this, one will approach the window while the other will stay back by the trunk, just in case.

Why It Is Less Common
This practice is becoming less and less frequent. Today, if you notice an officer doing this, it is likely an older officer who was trained to do so and does it out of habit. Many police academies don’t even teach this tactic anymore.

First of all, technology has made this practice nearly obsolete. There are traffic cams installed in a way that makes nearly every angle of the road visible. Cop cars are also now equipped with dash cams, and in many places, officers wear body cams, as well.

Violence against police is also a concern, and touching the tail light could position them directly behind the vehicle. This puts them at risk if the driver decides to reverse the car before the officer reaches the window. So while you’re less and less likely to experience this maneuver, if you ever do, now you know why.