Jon Hammar saw combat in Iraq and Afghanistan, but his most brutal foreign experience was in Mexico.

In August, the 27-year-old former Marine corporal was incarcerated by Mexican authorities in Matamoros for trying to register an antique shotgun with customs agents. Foolishly, Cpl. Hammar followed instructions given to him by U.S. Border Patrol agents in Brownsville, Texas. He registered the gun with them and brought the paperwork to the Mexicans to get their stamp of approval to carry the gun through the country. Hammar and a friend were driving a Winnebago, hoping to have a nice surfing vacation with some hunting on the side.

Even though the Mexican authorities clearly saw Hammar was trying to follow the rules, they seized the Winnebago and locked the corporal up in the notoriously corrupt CEDES prison anyway. There he was threatened by other inmates and told by guards that he could buy his way out of the hellhole by paying money to the “right people.”