The Iraq war veteran accused of killing five travellers and wounding six others at a busy international airport in Florida appears to have travelled there specifically to carry out the attack, authorities have said, but they do not know why he chose his target and have not ruled out terrorism.
Authorities said during a news conference yesterday that they had interviewed roughly 175 people, including a lengthy interrogation with the cooperative suspect, 26-year-old Esteban Santiago, a former National Guard soldier from Alaska.
Flights had resumed at the Fort Lauderdale airport after the bloodshed, though the terminal where the shooting happened remained closed.
FBI Agent George Piro said Santiago spoke to investigators for several hours after he opened fire with a 9mm semiautomatic handgun that he appears to have legally checked on a flight from Alaska.
"Indications are that he came here to carry out this horrific attack," Piro said. "We have not identified any triggers that would have caused this attack. We're pursuing all angles on what prompted him to carry out this horrific attack."
Investigators are combing through social media and other information to determine Santiago's motive, and it's too early to say whether terrorism played a role, Piro said.
In November, Santiago had walked into an FBI field office in Alaska saying the U.S. Government was controlling his mind and forcing him to watch Islamic State group videos, a law enforcement official said.
Santiago had not been placed on the US no-fly list and appears to have acted alone, Piro said.
The attack sent panicked witnesses running out of the terminal and spilling onto the tarmac, baggage in hand. Others hid in bathroom stalls or crouched behind cars or anything else they could find as police and paramedics rushed in to help the wounded and establish whether there were any other gunmen.
Mark Lea, 53, had just flown in from Minnesota with his wife for a cruise when he heard three quick cracks, like a firecracker. Then came more cracks, and "I knew it was more than just a firecracker," he said.
Making sure his wife was outside, Lea helped evacuate some older women who had fallen, he said. Then he saw the shooter. "He was just kind of randomly shooting people," he said. "If you were in his path, you were going to get shot. He was walking and shooting."
Over the course of about 45 seconds, the shooter reloaded twice, he said. When he was out of bullets, he walked away, dropped the gun and lay face down, spread eagle on the floor, Lea said.