The suspect in the deadly shooting at a Florida airport was charged Saturday with an act of violence at an international airport resulting in death, according to a statement by the Miami U.S. attorney's office.
Esteban Santiago, 26, an Iraq War veteran, is accused of killing five people and wounding six others in a shooting rampage Friday. The gunshots panicked thousands of people and threw the Fort Lauderdale airport into chaos.
If convicted of the charge, Santiago could face the death penalty or any prison sentence up to life.
Santiago also was charged with two firearms offenses, officials said.
He is being held without bail. He is scheduled to make his first court appearance in Florida Monday.
Traveled to Florida
Officials said at a news conference Saturday the suspect in the deadly shooting attack traveled "specifically" to Fort Lauderdale to carry out the attack, but the reason why remained unclear.
WATCH: FBI: Still considering terrorism in Florida shooting
Police interrogated Santiago for several hours until early Saturday. Authorities said he was cooperating with investigators.
George Piro, the special agent in charge of the Federal Bureau of Investigation's Miami office, told reporters Saturday that Santiago "came here specifically to carry out this horrific attack," but added it was unknown what triggered the shootings.
Police "continue to look at the terrorism angle" as a possible motive, Piro said, but it’s “too early in the investigation” to suggest a motive for the shooting.
The airport, shut down after Friday's attack, reopened slowly Saturday, with reports of security delays and long lines.
Mental health evaluation
In Alaska, where Santiago lived, the FBI and the Anchorage police chief said Saturday Santiago walked into a local FBI office in November in an agitated state. He made incoherent statements and told agents he had been hearing voices directing to join the terror group Islamic State.
Passengers wait in line at the Delta airlines counter in terminal 2 at the Fort Lauderdale-Hollywood International Airport in Fort Lauderdale, Fla., Jan. 7, 2017.
Santiago was carrying a pistol magazine loaded with bullets at the time, but said he had left his gun in his vehicle.
As is their practice, the FBI agents took his weapon.
Santiago was taken for a mental health evaluation and investigated, but authorities found no wrongdoing. They returned his gun to him in December. It is not clear if that pistol was used in the airport shootings.
Authorities in Florida said Santiago's weapon was properly stowed in a locked case inside his checked luggage. After landing in Fort Lauderdale, they said he retrieved his luggage, went to a restroom to unlock and load the gun, then walked back into the terminal area and began firing.
"There's no question we need to review not only the question of whether people should be able to travel with their firearms even if they're in checked baggage," said U.S. Representative Debbie Wasserman-Schultz, whose congressional district includes the airport, "but I think we need to take a hard look at the security around baggage claim areas..."
The FBI's Piro, who said mental illness also was being studied as a factor in the attack, told reporters: “We have conducted roughly 175 witness interviews, we’ve recovered video, physical evidence and we continue to pursue every investigative lead."
WATCH: News conference on Fort Lauderdale, Florida, shooting
Hospitalized after service in Iraq
Santiago's brother blames the government for not giving his sibling the help he needed and had requested from the FBI in Anchorage.
Bryan Santiago said his brother had asked the government for psychological help, but had received scant assistance, even after he said he was hearing voices and that "the government was writing to him in secret code . . . They already knew about the thoughts he was having. That angers me."
In Alaska, authorities defended their interactions with Esteban Santiago, saying the young man broke no laws when he walked into the FBI office "making disjointed comments about mind control."
This booking photo provided by the Broward Sheriff's Office shows suspect Esteban Ruiz Santiago, 26, Jan. 7, 2017, in Fort Lauderdale, Fla.
Esteban Santiago's uncle, Hernan Rivera, told the Star-Ledger newspaper in Newark, New Jersey: "Only thing I could tell you was when he came out of Iraq, he wasn’t feeling too good."
Santiago was a member of the Army National Guard from 2007 until late 2016 when he was discharged for unsatisfactory performance. Most of his service was either in Puerto Rico or Alaska, but he also served 10 months on active duty in Iraq in 2010-2011.
His aunt told the newspaper he was hospitalized after returning from Iraq. “It was like he lost his mind,” Ruiz Rivera said.