Baltimore plans to sue ‘ghost gun’ part maker as state law takes effect

Baltimore Mayor Brandon M. Scott said Tuesday that the city plans to sue Polymer80, one of the country’s largest manufacturers of “ghost gun” kits — untraceable firearms that have proliferated on city streets and contributed to a surge of violence. Officials plan to file the suit Wednesday, the same day a state law to ban the sale, receipt and transfer of an unfinished frame or receiver that does not have a serial number by the manufacturer takes effect.