FORT LAUDERDALE, Fla. (CBSNewYork/AP) — The Iraq war veteran held in the fatal shooting of five people inside Fort Lauderdale’s airport answered questions in a clear voice Monday as he was appointed public defenders and told he could face the death penalty.

Esteban Santiago, 26, appeared before U.S. Magistrate Judge Alicia Valle, who ordered him held until his next hearings.

Shackled in a red jumpsuit in the heavily guarded federal courtroom, Santiago answered mostly yes or no to questions, and told the judge he understands the charges, which include committing violence against people at an international airport resulting in death, and two firearms offenses.

She told him the death penalty could apply.

“We are telling you the maximum penalty allowed by law so that you understand the seriousness of the charges,” the judge said.

He said he had been in the Army, where he made about $15,000 a year. He mentioned expenses including $560 in monthly rent, plus phone and other utility bills. He said he owns no property and doesn’t have a vehicle. He said he had worked for a security company, Signal 88, in Anchorage, Alaska, until November, making $2,100 a month, but currently only had $5 to $10 in the bank.

Valle set a detention hearing for Jan. 17, followed by an arraignment for entering a plea for Jan. 23.

More than a dozen officers kept watch outside the courthouse, carrying rifles and wearing bulletproof vests. There were also mounted police and K-9 units.

Santiago has been in custody since Friday’s shooting at Fort Lauderdale-Hollywood International Airport.

The FBI has says Santiago flew on a one-way ticket from Alaska to Florida. He checked a single piece of luggage: a gun box for his Walther 9 mm semi-automatic pistol and two magazines of ammunition, according to an FBI affidavit.

Agents say he retrieved the box in baggage claim and loaded his weapon in a bathroom stall before opening fire on fellow passengers, killing five and wounding six others.

Surveillance video obtained by TMZ appears to show Santiago walking through the airport before he reaches into his waistband, pulls out a gun and begins firing. Startled passengers behind him are seen ducking for cover.

“By the time I was laying down, I wasn’t looking anywhere else,” said survivor Annika Lee Dean. “Looking at the carpet and praying to God that my children would have a mother.”

“He just kept shooting anyone that was in his path,” said witness Marc Lea. “He did not select anyone. He did not target anyone. He walked that path, you got shot.”

TMZ has not said where nor how it obtained the video and officials have not confirmed its veracity, CBS News reported.

Santiago, who was born in New Jersey but lived in Alaska, spoke to investigators for several hours after the shooting and allegedly confessed to planning the attack.

“We’re pursuing all angles on what prompted him to carry out this horrific attack,” FBI Agent George Piro said.

Investigators are combing through social media and other information to determine Santiago’s motive, and it’s too early to say whether terrorism played a role, Piro said.

In November, Santiago walked into an FBI field office in Alaska with a handgun and his infant child, saying the U.S. government was controlling his mind and forcing him to watch Islamic State group videos, authorities said.

“He was a walk-in complaint. This is something that happens at FBI offices around the country every day,” FBI agent Marlin Ritzman said.

Officers seized the weapon and local officers took him to get a mental health evaluation. His girlfriend picked up the child. On Dec. 8, the gun was returned to Santiago. Law enforcement officials tell CBS News it was the same weapon used in the attack.

Despite his mental evaluation, U.S. Attorney Karen Loeffler said Santiago would have been able to legally possess a gun because he had not been judged mentally ill.

“There is a federal law with regard to having a gun by somebody who is mentally ill, but the law requires that the person be adjudicated mentally ill, which is a difficult standard,” said Loeffler.

In Puerto Rico, Santiago’s mother says she spoke with him ten days before the shooting and that he sounded strange.

“I wanted to scream or cry, but since he was so far away, I could not do anything,” Elizabeth Ruiz said.

Santiago’s brother, Bryan Santiago, says the feds should have done more after his initial interaction with the FBI. Broward County Sheriff Scott Israel agrees.

“People like this shouldn’t have firearms. Period,” he said.

Meanwhile, a law enforcement source with knowledge of the investigation said Santiago booked a flight from Anchorage to Seattle to John F. Kennedy International Airport, and on to San Juan, Puerto Rico.

If Santiago had taken the flight, he would have arrived on New Year’s Day and could not have been present for the Times Square New Year’s Eve ball drop, sources told CBS News.

Santiago had a habit of booking flights and canceling them, sources said.

Santiago had not been placed on the U.S. no-fly list and appears to have acted alone, authorities said.

FBI agents have said they have uncovered no evidence yet linking Santiago to international terrorism. They say he apparently chose the Fort Lauderdale airport at random.

(TM and © Copyright 2017 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2017 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)