What's Ghost Gun, Used To Kill UnitedHealthcare CEO Brian Thompson

Luigi Mangione apparently used a ghost gun, a firearm that can be made at home, to shoot down the UnitedHealthcare CEO Brian Thompson, police said. The 26-year-old allegedly shot Thompson in the back and in the calf. "As of right now the information we're getting from Altoona is that the gun appears to be a ghost gun, may have been made on a 3D printer, with the capability of firing a 9mm round," NYPD Chief of Detectives Joseph Kenny told CBS NEWS.

As per the Pennsylvania criminal complaint filed after Mangione's arrest, the police officials found a black 3D-printed pistol and a black 3D-printed silencer while searching his backpack. 

"The pistol had a metal slide and a plastic handle with a metal threaded barrel...The pistol had one loaded Glock magazine with six nine-millimetre full metal jacket rounds. There was also one loose nine-millimetre hollow point round," the police affidavit said.

Thompson was killed in New York City on December 4, while the suspect, Luigi Mangione, was detained at a McDonald's in Altoona, Pennsylvania on Monday.

What is a ghost gun?

A privately made firearm, popularly called a 'ghost gun', can be assembled by people other than the licensed manufacturers, according to the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF).

It is difficult to track them, for they are made without any serial number. However, not all ghost guns are considered illegal, and not all firearms are supposed to have a serial number in the US, according to CBS News.

Ghost guns can be of any type -- a pistol, revolver, rifle, shotgun or machine gun.

More than 45,000 suspected ghost guns were reported to the ATF between 2016 and 2021,  recovered by police from potential crime scenes.

How to make them?

To make a ghost gun, people usually use a 3D printer or assemble it from a kit. These weapons can be made for less than $200, while officials have put the average price at roughly $500.

In the US, not all types of ghost guns are illegal. People in the country can make their own using 3D printing or other processes if the gun is "detectable," as per the Gun Control Act.