UPDATE 12:59 p.m. EST:
Esteban Santiago, the accused Florida airport shooter, said he carried out the deadly attack on behalf of ISIS, an FBI agent testified on Tuesday.
ISIS has not claimed responsibility for the attack. However, FBI agents said before the attack, Santiago said he was hearing voices and his mind was being controlled.
Esteban Santiago is due back in court 10 a.m. Tuesday for a pre-trial hearing. The hearing will determine whether Santiago will be released on bail, which is unlikely.
However, the hearing could determine whether he stays in a Broward County, Fla. jail or is transferred to a federal facility, USA Today reports.
Santiago, accused of killing five people in Ft. Lauderdale-Hollywood International Airport, could get the death penalty if convicted. He has not entered a plea.
I want to ensure these families that law enforcement is working tirelessly in order to ensure justice is served.
The FBI agent who interrogated Saddam Hussein for months after his capture will lead the investigation into Santiago's shooting, according to the Associated Press. George Piro, 49, runs the FBI's Miami field office. Terrorism has not been ruled out in the investigation, but Piro said it's "way too early" to find any clear links.
GRAPHIC | TMZ posted video it claimed showed the initial moments of the shooting.
Who is Esteban Santiago?
Esteban Santiago-Ruiz was born in New Jersey, lived in Alaska and Naples, Florida, and was discharged from the National Guard four months ago. He received a general discharge from the Alaska Army National Guard last year for unsatisfactory performance of his duties.
He had served as a member of the Puerto Rican National Guard for six years and served one year overseas in combat in Iraq, according to family members who spoke with the media.
The Associated Press contributed to this report.