Esteban Santiago, the suspected gunman that killed five people in a shooting at Fort Lauderdale airport has been detained, Florida police say.

According to reports, the 26-year-old Iraq war veteran may have been mentally disturbed. He reportedly said the government was controlling his mind and made him watch jihadist videos.

Officials say they have not ruled out terrorism as a possible motive.

Esteban Santiago opened fire at the baggage claim area of Terminal 2 as passengers were collecting their luggage. Witnesses said he walked along the carousels and did not say anything as he shot people who were trying to run or hide.

The attacker surrendered to police when he ran out of ammunition, witnesses added.

Image source Anchorage Police

Esteban Santiago, who was wearing a Star Wars T-shirt, had traveled from Alaska, officials said. He checked in an unloaded gun and ammunition with his luggage, and loaded the semi-automatic gun in the bathroom after landing and collecting his bag.

FBI’s George Piro told journalists: “We are looking at all avenues. We have not ruled out terrorism and we will be pursuing every angle to try to determine the motive behind this attack.”

Sheriff Scott Israel earlier said it appeared that the attacker had acted alone.

Esteban Santiago is expected to face federal charges and make his first appearance in court on January 9.

He is a former member of the Puerto Rico and Alaska National Guard, according to the Pentagon. The suspect served in Iraq from April 2010 to February 2011, and ended his service in August 2016.

He had received a general discharge from the Alaska National Guard for unsatisfactory performance.

George Piro said that Esteban Santiago had turned up at an FBI office in his hometown of Anchorage, Alaska, in November, behaving erratically and was turned over to local police, who took him to a medical facility for a mental evaluation.

“We looked at his contacts, we did our inter-agency checks and everything and, at that point, we closed our assessment,” he added, saying that Esteban Santiago had “clearly” stated that he did not intend to harm anyone.

An unnamed official quoted by AP news agency said that Esteban Santiago told FBI agents back then that the US government was controlling his mind and making him watch videos from ISIS.

Esteban Santiago’s brother said he had been receiving psychological treatment recently.