The only organization in the United States that is legally authorized to track the ownership of a firearm by the firearm's serial number is the Bureau of Alcohol, Tobacco, Firearms and Explosives. Only tribal, local, state, or federal law enforcement agencies are allowed to submit a request for a trace, according to the ATF.
Firearms are traced by their serial numbers through the ATF National Tracing Center. By act of Congress, the ATF is the only organization in the United States allowed to do so. The trace must be requested by a law enforcement agency in the course of an investigation into, or to prevent, a crime or an act of terrorism, reports the ATF.
A serial number trace tracks a firearm through the distribution chain from the manufacturer to the first person to purchase the item. Every firearm recovered at a crime scene undergoes a serial number trace as part of the investigation, according to the ATF.
Requests to trace a firearm by serial number can be filled through paperwork or electronically. The ATF website offers paperwork, and electronic requests are processed through the E-Trace system. Only law enforcement agencies can access the forms and E-Trace, notes the ATF.
The serial number trace is a labor and time-intensive process; however, as of 2013, 70 percent of traces successfully identify the buyer of the gun, National Public Radio reports.