By Agence France-Presse
Police identified the suspect as 26-year-old Esteban Santiago, who was in custody and being questioned by the FBI over the shooting that shut down the airport, a major gateway to the Caribbean and Latin America.
Santiago, who earlier complained that the CIA was forcing him to watch Islamic State jihadist videos, allegedly opened fire randomly with a semi-automatic handgun Friday shortly before 1:00 pm (1800 GMT) in the baggage claim area of Terminal 2.
The Fort Lauderdale airport announced at 5:00 am (1000 GMT) Saturday via Twitter that they were again open for business, but urged passengers to check with their airlines.
Witness John Schlicher told Fox News that he was picking up his first bag as he "heard the first shot. As I did, the person right next to me fell to the ground... It was very surreal."
The shooter "was holding a handgun. He was firing into the crowd. Everyone was standing there waiting for the luggage," he said.
Santiago had traveled from Alaska to Fort Lauderdale, with a stopover in Minneapolis, Minnesota, the special agent in charge of Miami's FBI field office, George Piro, told reporters late Friday.
"We're looking at several investigative leads not only in Alaska but other states that we have determined that he's either traveled to or has connections there," Piro said.
The suspect had a gun inside his checked luggage, after declaring the weapon with airport authorities, and then used it in the shooting rampage, law enforcement sources told US media.
Santiago was detained without law enforcement firing any shots, Broward County Sheriff Scott Israel told reporters.
Piro said authorities were "looking at every angle, including the terrorism angle," but that it would take time to determine the nature of the attack.
In November, Santiago had walked into the FBI's Anchorage office exhibiting "erratic behavior" that led agents to contact local police, who took him to a medical facility for a mental health evaluation, Piro said.
Santiago claimed he was being forced to fight for the Islamic State group and that the CIA was controlling his mind to make him watch IS videos, several US outlets reported, citing unnamed law enforcement officials.
Santiago, who was born in New Jersey and raised in Puerto Rico, is a former member of the Puerto Rico and Alaska National Guard. He served in Iraq from April 2010 to February 2011, and ended his service in August.
Santiago only reached the rank of private first class and was given a general discharge for unsatisfactory performance, ABC News reported.
An aunt, Maria Luisa Ruiz, told the NorthJersey.com news site that Santiago became a father to a baby boy in September -- and that he was having mental problems.
"Like a month ago, it was like he lost his mind," Ruiz said. "He said he saw things."
She added: "My family and I are in shock right now... It's sad but we have to confront the situation."
FBI agents later interviewed Ruiz, CNN reported.
Mayor Barbara Sharief told CNN that the gunman "was a lone shooter, and we have no evidence at this time that he was acting with anyone else."
Run and hide
In addition to those killed and wounded, up to 40 people went to the hospital for various other injuries such as falling and sprains, Israel said.
US President Barack Obama expressed "how heartbroken we are for the families who've been affected" during excerpts of an interview with ABC News.
Florida Governor Rick Scott, who rushed to the airport to be briefed, told reporters that those responsible would be "held accountable to the full extent of the law."
Scott said that he had contacted President-elect Donald Trump, who said that he was "monitoring the terrible situation in Florida."
"Thoughts and prayers for all. Stay safe!" Trump tweeted.
Airport personnel were also busy in the complicated task of returning nearly 20,000 pieces of luggage and other personal items abandoned by passengers fleeing at the time of the shooting, officials said.