SACRAMENTO, Calif. - A federal judge has sentenced a Montana man to three years in prison for trying to board a flight in Sacramento, Calif., with four loaded guns.

Harold E. Waller of Circle, Mont., was arrested in March 2012 as he attempted to pass through security screening with a loaded 9 mm handgun in a shoulder holster. Screeners also found guns and ammunition in his three carry-on bags.

The judge issued a stiffer sentence Wednesday than federal guidelines called for, saying Waller downplayed his actions and characterized them as a mistake.

The 46-year-old's mother, Helen Waller, previously told The Associated Press her son was being treated for depression at a Sacramento clinic before he bought a one-way ticket to Alaska.

He pleaded guilty to attempting to board an aircraft with a concealed weapon.