WASHINGTON — The Supreme Court on Wednesday upheld a federal restriction on the sale of parts kits that permit unlicensed gun owners to make firearms at home that cannot be traced by the police. In a 7-2 decision, the justices agreed these homemade weapons, often referred to as “ghost guns,” qualify as firearms under federal law.

Prosecutors in New York are warning 3D-printing companies their "insufficient security measures" are causing a "troubling rise in access to unregulated weaponry."