Former Marine Jon Hammar, who served combat tours in Afghanistan and Iraq, was arrested for illegally possessing an antique firearm even though he declared the gun to Mexican Customs agents. He is shown during surfing in Costa Rica in 2007. He could face up to 15 years in prison if convicted. (Photo courtesy Olivia Hammar)

Former Marine Jon Hammar, who served combat tours in Afghanistan and Iraq, was arrested for illegally possessing an antique firearm even though he declared the gun to Mexican Customs agents. He is shown during surfing in Costa Rica in 2007. He could face up to 15 years in prison if convicted. (Photo courtesy Olivia Hammar)