UPDATED: 1.14PM Investigators looking into the shooting at Fort Lauderdale airport are still not sure what motivated the shooter.

US prosecutors have filed charges against 26 year-old Esteban Santiago that could bring the death penalty if he is convicted.

 

Santiago is accused of fatally shooting five people and wounding six others last Friday at a Fort Lauderdale-Hollywood International Airport baggage claim.

Before the attack Santiago told the FBI he had voices in his head, and he had a history of erratic behaviour. 

He'd previously served in Iraq, but flew to Florida from Alaska with a gun legally checked in to his luggage.

FBI investigator George Piro said the man has had previous contact with the FBI, and was sent for a mental health evaluation.

"Indications are that he came here [to Florida] to carry out this horrific attack, we have not identified any triggers that would have caused this attack."

Special agent Marlin Ritzman said while the shooter was incoherent before the attack, there was no reason to think he was a threat.

"During our initial investigation we found no ties to terrorism. He broke no laws when he came into our office making disjointed comments about mind control."

The FBI said it's ruling nothing out as it looks for the motive. 

Fort Lauderdale police chief Scott Israel said the shooting shows America needs better gun controls.

He said weapons simply shouldn't be in the hands of people with mental health issues.

"We all know they're people with very real problems, but if they are suffering from a mental illness or they're on a no fly zone, a no fly list, or they're a convicted felon, they flat out shouldn't be allowed to own hand guns or rifles."

Santiago is currently being held without bail, and is scheduled to make his first court appearance tomorrow.