A coalition for 21 attorneys general from around the country led by New York's Letitia James has formed to defend state-level measures banning 3-D printed guns amid a challenge before the U.S. Supreme Court.

The firearms can be manufactured through downloadable materials and a 3-D printer in a person's home. New York in 2019 approved legislation banning 3-D guns, and other states have approved similar measures as well.

One of the main concerns among policymakers is the guns are essentially untraceable because they lack a serial number or other features that can make them identifiable.

“For years, we’ve been fighting Defense Distributed’s illegal efforts to make dangerous assault weapons more easily accessible to anyone with an internet connection,” James said.

“Despite the lawsuits we filed and the cease and desist letters we’ve sent, Defense Distributed has repeatedly taken steps to make it easier for criminals and terrorists to get their hands on guns and for anyone to print unregistered, untraceable, and, in many cases, undetectable firearms. We are fighting back to enforce our states’ laws and protect our schools, our workplaces, and our places of worship from turning into killing fields.”