The New Jersey Assembly Judiciary Committee advanced a bill Monday that would make it illegal to make 3D-printed guns or purchase parts to build a gun.

The bill would specifically target so-called “ghost guns” that are made and never registered with a serial number.

“What we’ve witnessed in a number of circumstances are people who are buying various parts of guns, not the gun itself, so there’s no registration requirement, but buying parts of guns, putting them together and having a functional gun. Effectively it makes what we call a ‘ghost gun,’” said Deputy Speaker Assemblyman Gary Schaer.

The bill will next go to the Assembly floor for a vote.

If the bill is passed, it would be the toughest gun law of its kind in the United States.