Nonetheless, judging whether an "assault pistol" is a real type of gun or not is not helped by a lack of standardized terms and is complicated by the political debate around the topic of gun control.

The semi-automatic Cobray pistol recovered in the Monterey Park, Calif., shooting, was modified with what appears to be a homemade suppressor.The gun is a subcompact variation of a MAC-10 pistol.

Part of the gun that the police believe was used to kill the C.E.O. of UnitedHealthcare was made by a 3D printer using a popular design found online. By Thomas Gibbons-Neff and Aric Toler At first ...