Maryland, 3D-printed

A 39-year-old man suspected of amassing an arsenal of firearms, including untraceable "ghost guns," has been taken into ...
These included fully automatic machine guns, semiautomatic rifles, shotguns and handguns, most of which were ghost guns ...
The St. Mary's County Sheriff's Office said they arrested a man on Tuesday who owned a collection of 3D-printed "ghost guns" ...