A gunman thought to be an Iraq veteran opened fire on Friday at Fort Lauderdale-Hollywood airport, killing five people and injuring eight, as panicked travelers fled for safety.
The suspect has been identified as 26-year-old Esteban Santiago. He was found with a military ID and is currently being questioned by the FBI.
The incident occurred in the baggage claim area of Terminal 2, as passengers collecting their luggage were interrupted by the alleged gunman.
A federal law enforcement official told Reuters that in November, Santiago turned up at a FBI office in Anchorage and told agents that his mind was being controlled by a US intelligence agency, which was ordering him to watch Islamic State videos.
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 person was already dead, he said.
Nearly two months ago a former Southwest Airlines worker killed an employee of the company at Oklahoma City's airport in what police called a premeditated act.
The deadliest mass shooting in modern US history took place last June, when a gunman apparently inspired by Islamic State killed 49 people and wounded 53 at a gay nightclub in Orlando, Florida.