From the U.S. Department of Justice, Bureau of Alcohol, Tobacco, Firearms and Explosives
The report gives an overview, for calendar year 2012, of the lost and stolen gun file entries in the National Crime Information Center (NCIC), and of the lost and stolen firearm reports submitted by Federal Firearms Licensees (FFLs) to ATF. This report will be updated and published annually.
Lost and stolen firearms pose a substantial threat to public safety and to law enforcement. Those that steal firearms commit violent crimes with stolen guns, transfer stolen firearms to others who commit crimes, and create an unregulated secondary market for firearms, including a market for those who are prohibited by law from possessing a gun. Moreover, thieves and illicit traffickers often obliterate the serial numbers of stolen firearms so that if a stolen firearm is later recovered by law enforcement, it cannot identified as stolen or traced to the original purchaser. Lost firearms pose a similar threat. Like stolen firearms, they are most often bought and sold in an unregulated secondary market where law enforcement is unable to trace transactions. As a result, when a lost or stolen gun is later recovered from a crime scene, tracing (which only identifies the original manufacturer, the licensed dealer who sold the firearm, and the original purchaser) will not provide a direct link to the perpetrator of the crime