A 25-year-old man tried to hide ammunition in dog biscuit boxes in order to smuggle it out of Texas and into Mexico.

According to the Fort Worth Star Telegram, U.S. Attorney’s Office for the Southern District of Texas announced Friday that Esteban Ramirez-Torres had been arrested in November for trying to smuggle 4,000 rounds of ammunition back into Mexico.The reports state Torres was nervous during a routine stop at the border and was shaking as he was trying to remove his identification from his wallet. Torres told officials that he had been shopping at Walmart in Texas and was returning home to Reynosa.

When investigating the dog food and dog biscuits in Torres' vehicle, officials found the boxes were either taped or stapled shut. Border Patrol and Custom's agents discovered 4,000 rounds of 7.62x39mm caliber ammunition and 30 AK-47 style rifle magazines in the boxes.

Torres has been in custody since November, with a trial scheduled for April. He faces 10 years in prison and up to $250,000 in fines.