WASHINGTON (Sputnik) — The 26-year-old Santiago was arraigned in federal court on a 22-count indictment and pleaded not guilty, NBC News reported.
Santiago boarded a plane headed from Anchorage, Alaska to Fort Lauderdale with a handgun. He loaded the gun in a bathroom and fired in a baggage claim area, killing five people and injuring 45 others.
Santiago has reportedly served in the US military and had previously been sent to a mental health facility.