People seek cover on the tarmac of Fort Lauderdale-Hollywood International Airport on Jan. 6. (Joe Raedle/Getty Images)

The man accused of killing five people during a rampage at Fort Lauderdale’s international airport earlier this month was indicted Thursday by a federal grand jury and, if convicted, could face the death penalty.

Esteban Santiago, 26, was taken into custody immediately after the Jan. 6 attack at Fort Lauderdale-Hollywood International Airport. Authorities said he opened fire at a baggage-claim area in an airport terminal, killing vacationers who had traveled to South Florida to board cruise ships.

The grand jury in Broward County, Fla., charged Santiago with 22 counts stemming from the shooting. That includes 11 counts of violence at an international airport that resulted in death or serious injury, according to the indictment, filed Thursday in U.S. District Court for the Southern District of Florida. He was also charged with six counts of using and discharging a firearm during a crime of violence and five counts of causing someone’s death by using a firearm.

All told, the charges “authorize a maximum penalty, upon conviction, of death or imprisonment for life or any term of years,” the U.S. Attorney’s Office for the Southern District of Florida said in a statement.

Santiago, an Iraq War veteran, had drawn police attention in his Alaskan home town. At least four times last year, police were called to his house for reports of physical disturbances or domestic violence. In the year before the shooting, he was arrested twice. And two months before the attack, authorities said, he walked into an FBI field office in Alaska and told agents that his mind was being controlled, claiming that the government was forcing him to watch Islamic State videos.

FILE- This file booking photo provided by the Broward Sheriff's Office shows suspect Esteban Santiago in Fort Lauderdale, Fla. Santiago, the Iraq war veteran accused of fatally shooting multiple people and wounding several others at a crowded Florida airport baggage claim, is due for his first court appearance Monday, Jan. 9, 2017. (Broward Sheriff's Office via AP) Esteban Santiago. (Broward Sheriff’s Office via AP)

Police took his gun for a month but then returned it, officials said.

Still, despite his run-ins with the law and his encounter with the FBI, authorities said Santiago was able to board two flights — one from Anchorage to Minneapolis, and then another taking him to Fort Lauderdale — checking a bag containing only his firearm.

A day after the shooting, Santiago was charged with federal crimes. An FBI affidavit filed that same day said Santiago retrieved the box with his 9mm semiautomatic handgun and two magazines, loaded the gun in a bathroom and then walked into a crowded baggage-claim area, where he “fired approximately ten to fifteen rounds of ammunition from his firearm, aiming at his victims’ heads.”

Santiago was “shooting in a methodical manner,” the affidavit said, before he apparently ran out of ammunition, put down his gun “and dropped to the floor.” He was arrested then by Broward County sheriff’s deputies.

Relatives have said that Santiago had a history of mental health problems, while his aunt and uncle told Newark’s Star-Ledger newspaper that some of his issues followed his return from Iraq. His uncle said Santiago had gotten the help he needed and became a father last fall, but his condition worsened in December.

Officials have not decided yet whether they would pursue a rare federal death sentence for Santiago. But the indictment does list multiple special findings drawn from the federal death-penalty statute as factors warranting such a sentence. That includes killing people during the commission of another crime, “substantial planning and premeditation” and the fact that three of the victims were deemed “particularly vulnerable due to old age.” (The federal death-penalty statute includes among its factors that can warrant a death sentence whether victims are particularly young or old.)

Along with the indictment, a form filled out by a federal prosecutor noted that this remains “a potential death penalty case.” The decision about seeking a death sentence is made by the attorney general. President Trump’s pick for that position, Sen. Jeff Sessions (R-Ala.), has not been confirmed.

Further reading:

Suspect in Fort Lauderdale shooting charged with federal crimes

Fort Lauderdale airport reopens after shooting rampage