April 26, 2017 0403 GMT
The Justice Department on Saturday charged Esteban Santiago, 26, with firearms offenses and carrying out an act of violence when he opened fire at the busy Fort Lauderdale airport, AFP reported on Sunday.
Santiago, who had earlier shown signs of "erratic behavior," arrived Friday on a flight from Alaska.
At baggage claim he retrieved a 9mm semiautomatic handgun and ammunition that he had declared and stowed inside his checked luggage, then allegedly loaded the weapon in a bathroom and opened fire in the crowded baggage claim area of Terminal 2.
Once his ammunition was exhausted Santiago lay on the floor with his arms and legs spread out and peacefully surrendered when a sheriff deputy approached him, witnesses quoted in US media said.
The hail of bullets sent thousands scrambling for safety and shut down the airport, a major gateway to the Caribbean and Latin America, for about 16 hours.
If convicted of the charges Santiago could face the death penalty or life in prison, US Attorney Wifredo Ferrer said in a statement.
Santiago is scheduled to make an initial court appearance today.
A former member of the Puerto Rico and Alaska National Guard, Santiago served in Iraq from April 2010 to February 2011. He ended his service in August.
On November 7, Santiago walked into the FBI's office in Anchorage, Alaska and complained that his mind was being controlled by national intelligence agencies, which were forcing him to watch Islamic State jihadist videos, authorities said.
This "erratic behavior" led agents to contact local police, who took him for a mental health evaluation, FBI special agent George Piro said.
Santiago's brother, Bryan, criticized the way authorities handled his case.
"They had him hospitalized for four days and they let him go. How are you going to let someone leave a psychological center after four days when he said he hears voices that the CIA is telling him to join certain groups?" Bryan Santiago told CNN in a Spanish-language interview the network translated into English.