The Iraq war veteran who fatally shot five random victims in the Fort Lauderdale airport will be charged Monday with three federal crimes — each punishable by death.

Esteban Santiago, 26, faces one charge of committing an act of violence at an international airport resulting in death, and two federal weapons violations, CNN reported Saturday night.

The counts “represent the gravity of the situation and reflect the commitment of federal, state and local law enforcement personnel to continually protect the community and prosecute those who target our residents and visitors,” US Attorney Wifredo Ferrer said.

FBI special agent George Piro said earlier Saturday that the killer “came here specifically to carry out this horrific attack.”

There is no sign Santiago’s murderous run through a baggage-claim area on Friday was set off by any altercation, Piro said.

“We have not identified any triggers that would have caused this attack.”

Santiago has spent hours cooperating with investigators, telling cops he thinks he fired 15 shots.

Six people were also injured.

On Saturday, the gunman appeared exhausted.

“Santiago has been sleeping all day. He has not eaten anything or interacted with anyone,” a source told The Post.

Police are investigating whether Santiago is a homegrown terrorist, and to what extent his mental health contributed to the shooting.

The National Guard veteran had walked into an FBI office in Alaska two months ago, claiming voices in his head urged him to join ISIS.

He had driven to the office and walked in, leaving in his car his newborn baby — and a gun, it was reported Saturday.

Santiago was at that point briefly hospitalized and his gun taken away. It was released to him on Dec. 8.

Sources told CNN Saturday that this was the weapon he used in his airport rampage.

“During our initial investigation, we found no ties to terrorism. He broke no law when he came into our office,” said Alaska FBI Special Agent in Charge Martin Ritzman.

FBI agents reached out at the time to Anchorage police, who had previous run-ins with Santiago.

In January 2016, he was charged with trying to strangle his girlfriend, breaking down a bathroom door to get to her, screaming, “Get the f- -k out, b- - -h,” and hitting her in the head, Alaska court documents say.

In February, Santiago allegedly violated an order to stay away from the woman. He violated the order again in March and October, said Anchorage Police Chief Christopher Tolley.

“The FBI failed . . . We’re not talking about someone who emerged from anonymity to do something like this,” Bryan Santiago, his brother, told The Associated Press on Saturday, speaking outside his home in Puerto Rico.

“The federal government already knew about this for months. They had been evaluating him for a while, but they didn’t do anything.”

He added that his brother had sought psychological help but barely got any.

“I told him to go to church or to seek professional help,” he said.

The soldier’s uncle, Hernan Rivera, said Santiago “had problems with his mind and they didn’t help him.”

Santiago, who worked as a security guard, went to Alaska on his own three years ago to find a job.

He wasn’t the same after he returned from Iraq, said Rivera, adding Santiago had been in an out of mental-health treatment.

“He never told nobody what happened,” the uncle told The Post at his home in Union City, NJ.

Santiago’s mom, Elizabeth, was hospitalized with a breakdown after the shooting. “She’s doing bad,” Rivera said.

Born in New Jersey, Esteban Santiago moved to Puerto Rico at age 2 and grew up there. He joined the National Guard in 2007 and served two tours in Iraq.

Santiago also served a stint in the Alaska National Guard but was discharged for “unsatisfactory performance” after going AWOL several times, officials said.

Santiago fathered a boy in September 2016, media reports said.

Santiago flew from Anchorage to Minneapolis-St. Paul and connected to Fort Lauderdale on Friday.

In Fort Lauderdale, he picked up his checked baggage and pulled a gun from his bag. It is legal to carry unloaded firearms in checked baggage.

Then Santiago dashed in to a bathroom to change his shirt, and presumably load his gun. He came out shooting, authorities said, executing his victims with bullets to their heads.

He reloaded twice as terrified travelers fled for their lives.

When he was done, Santiago simply laid down on the ground, police said. He was taken into custody without incident.

The airport reopened for commercial flights at 5 a.m. Saturday.

Terminal 2, where Santiago went on his shooting spree, remained closed.

“My heart goes out to everyone who was displaced yesterday,” said Florida Gov. Rick Scott.

“I just think about this — I’m a dad, I’m a granddad. I just can’t imagine this happening to my family or any family.”

Additional reporting by Dean Balsamini, Liz Pressman and Post Wire Services