From The Four Major Ways Criminals Get Guns
First we need to identify the ways in which they currently do come into possession of weapons. We'll eliminate one common fallacy right away, that criminals get guns from other criminals. This may be true as far as it goes, but it doesn't help us in our analysis. We're interested in the original source of guns that are used in crime. If, for example, a gun is stolen during a burglary and passed from criminal to criminal before being used in a murder, that gun came from "Theft," which is one of our main categories.