Shocking news came out yesterday morning that United Health Care CEO Brian Thompson was murdered outside a New York City hotel. Authorities believe it was a targeted attack and someone was definitely after Thompson. Warning: Graphic Video.

The chilling video captures the moment when the CEO was shot in the back at close range by the hooded suspect.

Minnesota Now logo
Get our free mobile app

When watching the video, many people first believed that the gun was jamming when the shooter fired multiple shots. When I first saw the video, it looked to me like he was cycling the weapon.

It turns out, this could actually be the case. Experts are now saying that the gun used is a rare assassin's gun that was developed in World War 2. The gun is called a Welrod pistol. It was developed for the British Special Forces in World War 2 as a naturally quiet weapon used in covert operations.

Read More: Another Serial Killer From Wisconsin Featured In Netflix Series

Silencers are illegal, and really hard to find. If you don't want to make a lot of noise, this would be the weapon of choice. The original Welrod pistols were .32 caliber. However, later models were 9mm. 9mm shell casings were found at the scene.

It's really surprising at how quiet the Welrod is. Check out this video of the .32 caliber version. Instead of a loud crack of gunfire, it sounds more like a thump.

Now, for the 9 mm, it sounds even quieter for me. This was likely the gun used in the murder.

That gun sounds about as loud as a pellet gun. Insane!

This gun isn't cheap either. B&T Station Six-9 Suppressed Pistol is the modernized version of the Welrod pistol. They are listed out of stock from Capitol Armory and cost over $2,000!

25 True Crime Locations: What Do They Look Like Today?

Below, find out where 25 of the most infamous crimes in history took place — and what the locations are used for today. (If they've been left standing.)

More From Minnesota Now