| Last updated
If you've ever been pulled over, particularly in the US, you may have noticed the officer briefly touching the back of the car before approaching the window. Have a look at what we're talking about in the video below:
Well, apparently it's all part of standard policing procedure, and could help protect both the people in the car and the police officer from harm.
According to people in the comments, it's so the officer's fingerprints are on the car in case anything happens to them during the stop.
And this theory has been backed up by traffic safety expert Trooper Steve Montiero, who explained that it's a vital part of policing.
Speaking to News 6, he said there are two reasons behind it.
He said: "When law enforcement officers conduct a traffic stop, there are plenty of procedures that need to be done, not only for the safety of the violator, but for the safety of that officer.
"One of those things is proving that that officer was with that car, so when officers approach a vehicle, they touch the rear of it."
He went on: "The first reason is to make sure that the trunk is closed.
"It may sound a little crazy, but you want to make sure that no one is about to jump out of the trunk and that it's properly secured.
"Touching the rear of the vehicle puts the officer's fingerprints on that car, showing that he or she was there with it.
"In case the driver decided to flee the scene, or if something happened to that officer, it ties both the vehicle and the officer together."
He added: "This is just one of the many things that take place during traffic stops to ensure everyone's safety."
Since it was posted, the video has been watched over 21 million times, with hundreds piling into the comments to share their thoughts on it.
One user said: "I am a law enforcement student in Arizona, and we were taught to do that not only for the finger print but to make sure the back is closed."
Another echoed: "We also do it to make sure the trunk is closed, so no one pops out to shoot us.
"At least that's what I was taught at the academy over 20 years ago."
Chosen for YouChosen for You
Most Read StoriesMost Read