There are mounting concerns over the proliferation of 3D-printed weapons amid growing arrests across Europe of people downloading and or trying to build their own guns. "All you need is a weekend's worth of time and $50 for the materials". That was the advice of Stephan Balliet, a German Neo-Nazi who has been sentenced to life in prison for killing two people after attempting to attack a synagogue in the city of Halle on October 9, 2019. Balliet, 27, was referring to... (GunPolicy.org)