In the torrent of news coverage of Luigi Mangione, charged in the shooting death of UnitedHealthcare CEO Brian Thompson, the news coverage has revolved around the surprising level of rejoicing and much speculation as to the motive.

But at Futurism, staff writer Frank Landymore reports on a detail that might prove telling in the future: Both the handgun and the silencer were apparently 3D-printed.

Initially, authorities had only suggested that the weapon may have been 3D-printed, but were certain that it was a variety of “ghost gun”: a homemade firearm assembled from parts sourced outside regulated channels that come with no serial numbers and are almost impossible to trace.

However, police have not determined whether the 26-year-old Mangione printed or assembled the gun parts himself or if he purchased the weapon from someone.

“Cops Say CEO Shooter’s Pistol and Silencer Were Both 3D-Printed,”

According to law enforcement experts, he says, this is the first really significant case traced to a 3D-printed weapon.

3D-printed guns and gun parts are generally legal in the US, allowing owners to skirt federal oversight when obtaining these weapons. This is especially useful with a gun’s lower receiver, or “lower,” because it’s the only individual gun part that federal law requires background checks to buy from licensed dealers. Other parts, like the slide, barrel, and trigger mechanism, aren’t regulated and can be bought from aftermarket vendors, according to Chittum. “Both 3D-Printed,”

One issue for law enforcement is that 3D-printing technology is easy to acquire (relative to building or buying a conventional firearms factory). Such guns have no serial number and are not traceable. They may become a new factor in targeted killings.

You may also wish to read: Murdered insurance CEO’s death triggers widespread rejoicing. The shooting appears to have been targeted. His company is accused of using an algorithm that unfairly denies benefits to sick policyholders.