That it is now (actually for the past several years) possible to make a firearm via 3D printing is irrelevant. It has always been possible to make usable firearms, at home, with readily available tools and materials. Such guns have been extremely variable in quality and servicablity, but they shoot (at least once). Plastic, 3D printed firearms are usually even less durable, accurate, or useful. The kind of 3D printers which can make things out of metal, and the powdered alloys needed to use them, are far more expensive and far less accessible than simple hand and power tools and the metals which are already available. “Got a Dremal? Got a gun.”
Zip guns? Way before computers and 3D printers. What an idiot. Saddens me to think of what the NE corner of the US has become. No doubt my kin folk are spinning in their graves. (Ref the sheriff being from NJ)