An Iraq war veteran took a gun out of his checked luggage and opened fire in a crowded baggage claim area at Fort Lauderdale’s airport on Friday, killing five people, months after he showed up at an FBI office behaving erratically, according to authorities. Esteban Santiago, 26, who was taken into custody immediately after the shooting and questioned at length, was expected to face federal charges in the shooting rampage, said George Piro, special agent in charge of the FBI’s office in Miami.