JACKSON, Miss. - Former Mississippi Gov. Haley Barbour says he will pay a fine after being arrested with a loaded handgun in his briefcase as he went through an airport security checkpoint.

Barbour - Republican National Committee chairman in the mid-1990s and governor from 2004-12 - told The Associated Press on Tuesday he was trying to board a flight Jan. 2 from Jackson to Washington. He said he forgot he was carrying the gun, which he had put in his briefcase after an assistant removed it from his car days earlier.

“This was absentmindedness and nobody’s fault but mine,” said Barbour, 70, who lives in Mississippi and frequently travels to Washington for his job as a lobbyist.

Transportation Security Administration spokeswoman Lisa Farbstein said a TSA officer working at an X-ray machine at a checkpoint at Jackson-Medgar Wiley Evers International Airport spotted a .38-caliber revolver, loaded with five bullets, in a passenger’s carry-on bag. TSA contacted airport police, who arrested the passenger. The TSA would not release the passenger’s name, but Farbstein confirmed it was a former governor, and Barbour confirmed to AP that it was he.

Barbour said he did not dispute Farbstein’s use of the word “arrest,” though he said he was not handcuffed and no mugshot photo was taken. Barbour described the TSA officers and the airport police as “very nice but very professional.”

“They did exactly what they should have done, which was treat me like anybody else,” Barbour said.

The fine for having a loaded firearm at an airport checkpoint begins at $3,920, according to a TSA website .

AP filed a public records request with the Jackson airport authority Jan. 23, seeking a copy of a police report from the Jan. 2 incident. State law gives a government seven working days to respond, and the airport had not done so by Tuesday.

Barbour said the gun was confiscated and he boarded his flight to Washington.

“Next time, I’ll be more observant about getting stuff out of my briefcase,” he said.