FORT LAUDERDALE (Florida) • The gunman said nothing as he fired on fellow passengers in the crowded baggage claim area, witnesses said.
Using a 9mm semi-automatic handgun, he kept firing, stopping only after running out of ammunition. He then surrendered to police.
The gunman, identified as Esteban Santiago, 26, is now in custody and is expected to face federal charges in the shooting rampage at Florida's Fort Lauderdale airport, said Mr George Piro, special agent in charge of the Federal Bureau of Investigation's office in Miami.
Five people were killed and eight others were wounded by gunfire, and about three dozen were taken to local hospitals with bruises or broken bones suffered in the chaos surrounding the massacre at 1pm on Friday (2am yesterday, Singapore time).
"This is a senseless act of evil," Florida Governor Rick Scott told reporters.
SAVED BY HIS BACKPACK
The backpack saved my life. I felt something hit my back. It was only later when I went to the bathroom to check myself out that (I found) the bullet had entered my backpack, hit my laptop... later when I gave my backpack to the FBI for investigation they found the bullet in the pocket of my backpack.
MR STEVE FRAPPIER, on how his backpack may have stopped a shot from the gunman.
Federal investigators are now pursuing all angles in determining the motives for the attack by Santiago, an Iraq war veteran. Some officials said it was too early to tell whether Santiago was inspired by terrorist groups, including the Islamic State in Iraq and Syria (ISIS).
Broward County Commissioner Chip LaMarca said on Twitter that the gun was in Santiago's checked baggage. The gunman went from the luggage claim area to a restroom to load his weapon and came out firing indiscriminately.
Cellphone video posted on social media showed travellers kneeling and treating victims on the floor next to a luggage carousel. At least two victims had pools of blood from apparent head wounds.
A White House spokesman said US President Barack Obama had spoken to Mr Scott and Broward County Mayor Barbara Sharief and had extended his condolences to the loved ones of the victims.
Mr Piro said Santiago had turned up at an FBI office in Anchorage in November last year behaving erratically and was turned over to local police, who took him to a medical facility for mental evaluation.
A federal law enforcement official told Reuters that Santiago told agents at the Anchorage office in November that his mind was being controlled by a US intelligence agency, which was ordering him to watch videos from ISIS.
After the rampage, a witness described how his backpack and laptop may have spared his life.
"The backpack saved my life," Mr Steve Frappier said, speaking on CNN's AC360.
"I felt something hit my back," he said, speaking to CNN's Anderson Cooper. "It was only later when I went to the bathroom to check myself out that (I found) the bullet had entered my backpack, hit my laptop... later when I gave my backpack to the FBI for investigation they found the bullet in the pocket of my backpack."
Flying with firearms is routine and legal in the US as long as the guns are kept in a locked, hard-sided container as checked baggage only, under Transportation Security Administration rules. Ammunition is prohibited in carry-on bags but is allowed in checked luggage.
Mr John Schlicher, who told MSNBC he saw the attack, said the shooter was "directly firing at us" while passengers waited for their bags. His wife gave first aid to a victim who had been shot in the head, and his mother-in-law used her sweater to tend to another victim but it turned out that the person was already dead, he said.
Mr Mark Lea, another eyewitness, told MSNBC: "He didn't say anything; he was quiet the whole time."
Fort Lauderdale-Hollywood International Airport is the second-largest in South Florida, serving as an intercontinental gateway.
The airport reopened at 5am yesterday (6pm Singapore time).