The suspected shooter in Friday's deadly rampage at a Fort Lauderdale airport was charged on Saturday with federal counts that could carry the death penalty.
Esteban Santiago, 26, was charged with performing an act of violence against a person at an airport serving international civil aviation and two other counts, the U.S. Attorney's Office for the Southern District of Florida said. Five people were killed in the shooting rampage at the baggage claim of Fort Lauderdale-Hollywood International Airport at around 12:55 p.m.
Court documents say Santiago told the FBI after the shooting that he planned the attack, buying a one-way ticket from Anchorage and checked a box with a Walther 9 mm handgun and the two ammunition magazines he used in the shooting.
More from NBC News:
Santiago had been treated for mental health issues in Anchorage, where he lived, officials said. His aunt told NBC News that the former National Guardsman was "not OK" after returning from a 10-month deployment in Iraq.
In November Santiago walked into the FBI office there and complained his mind was being controlled by a U.S. intelligence agency, the FBI said Saturday. He was taken for a mental health evaluation and his gun was taken from him for safe keeping. The gun was returned in December.
The FBI in Alaska said there was no reason to place him on a no-fly list. A federal prosecutor there told reporters there it appeared there was no reason under the law to deny him his gun, and federal law requires a person be "adjudicated mentally ill" for the gun to be held by police.
Federal guidelines allow for passengers to check unloaded guns in a locked case, and also allows for ammunition to be placed in checked baggage.
"During our initial investigation we found no ties to terrorism," FBI Special Agent in Charge of the Anchorage office Marlin Ritzman told reporters. "He broke no laws when he came into our office making disjointed comments about mind control."
Investigators say Santiago fired ten to fifteen rounds of ammunition from his handgun, shooting all the rounds in one magazine, then reloading and emptying the second.
Santiago aimed at his victims' heads during the rampage until he ran out of bullets, the U.S. Attorney's Office said. Six people were wounded. Santiago dropped his handgun and got on the ground to wait for police, witnesses said.
The charges against Santiago also carry the possibility of life in prison, the U.S. Attorney's Office said. He is expected to appear in a Fort Lauderdale federal court Monday morning.
Police said Santiago took off from Anchorage and arrived at Fort Lauderdale-Hollywood International Airport on Friday on a connecting flight from Minnesota. At the baggage claim, they said, Santiago retrieved a weapon and began shooting.
Why remains a mystery.
Santiago's brother said they have family in Florida but had no idea why he was there — or why he allegedly went on a shooting spree.
"He is a regular person, spiritual, a good person," Bryan Santiago said.
Santiago's aunt and uncle in Union City, New Jersey, said Santiago was the father of a son named Pierre and that the boy and his mother both live in Puerto Rico. They, too, had no explanation for the shooting, but suspected it might have been related to his war experience.
"When he came back from Iraq, he wasn't feeling good," Hernan Rivera told NBC News. Santiago's aunt, Maria Luisa Ruiz, said they were told that he "got a little sick" around December, started to hear things, and was in treatment.
Santiago was born in Hamilton, New Jersey, and raised in Peñuelas, Puerto Rico, where his mother still lives. His father died four years ago.
Six years ago, Santiago enlisted in the Puerto Rico National Guard, his brother said.
"He was pro-America," Bryan Santiago said.
Two years ago, Santiago moved to Alaska, where he lived with a woman and a child and where he worked as a security guard, his brother said. He also owned a handgun.
In January of 2016 he was charged in with criminal mischief and a misdemeanor count of assault after he allegedly broke open the door of a bathroom and yelled and choked his girlfriend, according to police records. The case was dismissed in March, according to online records. A call to an attorney listed as representing Santiago was not immediately returned.
Santiago was not harmed during his arrest after the shooting in Florida, and no law enforcement officers fired any shots, Broward County Sheriff Scott Israel said. Investigators believe he acted alone, Israel said.
FBI Special Agent in Charge George Piro of the Miami division said Friday night that investigators are not aware of any incident that occurred on the flight or in the baggage claim area before Santiago opened fire.