The aftermath of last month's mass shooting in Orlando followed an all too familiar pattern: While politicians argued for and against tighter restrictions on guns, Americans rushed to buy more of them.
See FBI background checks state by state
Update, July 7: A previous version of this graphic said an estimated 40 percent of gun sales are not subject to background checks. This widely cited number is the subject of controversy. The graphic has been changed to move the 40 percent figure to the methodology section, which includes a reference to the debate and to new research by the Harvard Injury Control Research Center.
Source: FBI NICS (National Instant Criminal Background Check System), Bureau of Alcohol, Tobacco, Firearms and Explosives, and Bloomberg.
Additional work by David Ingold and Yvette Romero
1. In February and March 2014, North Carolina attempted to recheck all of their current permit holders, which accounts for the inflated numbers. For the purposes of this analysis, those two months were interpolated before being added to the totals.
After 2006, Kentucky began monthly background checks on concealed carry permit holders, which inflates their statistics relative to other states. For the purposes of this analysis, Kentucky was left out of U.S. totals for FBI background checks as a proxy for gun sales.
Other states may also include rechecks in their reporting to lesser degrees.
2. For the purposes of this analysis, the NICS data was seasonally adjusted using the United States Census Bureau's X-13ARIMA-SEATS. Seasonal adjustment is a common statistical technique that removes repeating seasonal patterns from time-series data. Read more about it here.
3. There's been some controversy over the estimate that 40 percent of firearms are purchased at gun shows or over the internet, bypassing federal background checks. References to this figure often cite a 22-year old study that surveyed a small sample of gun owners.
However, the Harvard Injury Control Research Center has been working on more recent research that surveyed 2,072 gun owners last summer. While the full report has not yet been published, the researchers shared initial findings with the Trace: among all gun transactions in the study—which includes gun shop sales, purchases made at gun shows and over the Internet, trades, gifts and inheritances—respondents said approximately 40 percent were not subject to an FBI background check.