TUCSON (AP) — A Mexican police officer was sentenced Tuesday to eight months in federal prison for unlawful possession of ammunition.

Federal prosecutors say 51-year-old Santiago Gutierrez-Othon, of Hermosillo, Sonora, was seen leaving a gun show at the Pima County Fairgrounds with a box of ammunition on March 8.

Law enforcement officers stopped his vehicle for a traffic violation and say Gutierrez-Othon first denied purchasing any ammunition.

When officers discovered 500 rounds of ammunition for an AR-15 rifle in the trunk of his car, they say Gutierrez-Othon admitted to the purchase. They also say Gutierrez-Othon stated that he planned to bribe Mexican customs authorities to bring the ammunition into Mexico.