It is legal to bring unloaded firearms onto a plane in checked baggage, and there are specific procedures for packing and handling them. Esteban Santiago legally brought a Walther 9 mm semi-automatic handgun to Fort Lauderdale on a flight that originated in Alaska on Jan. 6. When he landed, he retrieved the weapon from a baggage office, loaded it, and went on a rampage, killing five and wounding six. He's been charged with murder, attempted murder and other crimes and is set to go to trial in federal court in January.