The Bureau of Alcohol, Tobacco, Firearms and Explosives traced more than 211,000 guns back to their original point of purchase on behalf of law enforcement agencies in 2016. Of those, roughly 71 percent were originally sold in the state they were found, while the rest were from out of state. This interactive map shows the pattern of how guns move from state to state.
Note: Map shows only the top 10 out-of-state sources for traces run from each state; Data: Bureau of Alcohol Tobacco Firearms and Explosives; Chart: Chris Canipe
Go deeper: How guns move across state lines