The Transportation Security Administration (TSA) levied civil penalties of approximately $1.45 million against travelers who violated firearms regulations at airports around the country last year, records show.

The TSA filed more than 4,000 actions against gun-carrying travelers in 2017, according to data obtained through a request made under the Freedom of Information Act (FOIA.) Many of the civil claims arose from guns taken into a handful of U.S. airports that are among the busiest hubs and in the South or West. These claims are often levied in addition to criminal charges filed by state and local law enforcement agencies against air travelers who fail to follow firearms laws at the nation’s airports.

The TSA declined to identify those violators in the FOIA records, citing privacy restrictions. The highly redacted data does not even include individual case numbers because the TSA considers those private, too.

For several years, the TSA has reported finding record numbers of firearms at airport checkpoints as both the number of people flying and the number of people legally carrying firearms have increased. The agency has expressed concern not only because of the potential safety threat that firearms pose inside an airport or on a plane, but also because of the disruptions created at security checkpoints when a gun is found.

Just this week, TSA officers at Reagan National Airport stopped an Arlington, Va., woman coming through a checkpoint whose carry-on bag contained a loaded 9mm pistol, including a round chambered and ready to fire. The TSA said this was the 13th time this year that someone being screened by security at the airport had been found with a firearm. That figure ties the number of firearms identified there in 2017, the TSA said. The woman arrested Tuesday was not identified in the TSA news release.

Her arrest came just a few days after a Hagerstown, Md., man carrying a collapsible rifle tried to board an airplane at Baltimore-Washington International Marshall Airport. He told TSA officers he didn’t know he was carrying the .40-caliber rifle because his mother had packed his bag, a TSA spokeswoman said. The man, who was arrested Friday, also was unnamed in the TSA news release about the incident. Travelers who take firearms to checkpoints can face state or local criminal charges. The TSA can also file federal civil claims of up to $13,000.

Still, the data provided by the TSA in response to a FOIA request offers at least a narrow look at the agency’s use of civil monetary sanctions to discourage unlawful carrying of firearms at the nation’s airports.

About one-quarter (954) of the civil claims arose from guns detected at the following six airports: Atlanta’s Hartsfield-Jackson International; Dallas-Fort Worth International; George Bush Intercontinental in Houston; Phoenix Sky Harbor International; Denver International; and Dallas Love Field.

Most claims — 3,932, or about 96 percent — arose from guns detected as passengers went through security screening with carry-on bags. Ten claims arose from firearms found unlawfully packed in checked baggage. Although it is legal to fly with firearms in checked baggage, they must be packed in a specified manner and declared when the bag is checked.

A few, however, were found at other locations, including in “sterile” areas that are presumably free of threats because people must be screened to enter those airport zones. Seven firearms were found at passenger boarding gates, for example, and five were detected in “sterile” areas where only screened people are admitted.

In addition, two civil claims were issued against unidentified people who took firearms to “known crewmember portals.” These are special lanes set up at some airports so that participating flight crews may bypass regular screening lines by using a special badge. The program — a federally approved joint initiative of Airlines for America, which is the industry’s lobbying arm, and the Air Line Pilots Association International — is designed to make screening more efficient by taking flight crews out of the regular lines.

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