The 23-year-old gunman charged in a deadly shooting at Los Angeles International Airport told authorities at the scene that he acted alone and had been dropped off at the airport by a friend.
Authorities do not believe the friend knew that Paul Ciancia, the man charged in the attack, planned to open fire inside LAX's Terminal 3 just moments later, killing one Transportation Security Administration officer and wounding three other people, including two more TSA workers.
Ciancia was dropped off in a black Hyundai and was not a ticketed passenger. He was able to respond to investigators' questions at the scene Friday, a source told AP.
Ciancia, an unemployed motorcycle mechanic who grew up in the small, working-class town of Pennsville, New Jersey, was shot four times and was under 24-hour armed guard at a hospital. Ciancia was sedated for medical reasons, the official said, adding that one gunshot to the mouth blew a molar out of the suspect's jaw
Federal prosecutors charged Ciancia yesterday with murder of a federal officer and committing violence at an international airport. The charges could qualify him for the death penalty.
In court documents and interviews, authorities spelled out a chilling chain of events, saying Ciancia walked into the airport, pulled a .223-calibre assault rifle from his duffel bag and fired repeatedly at point-blank range at 39-year-old TSA officer Gerardo I. Hernandez, killing him.
He then fired on at least two other uniformed TSA employees and an airline passenger, who all were wounded, before airport police shot him as panicked passengers cowered in stores and restaurants, authorities said.
It wasn't clear why Ciancia targeted TSA officers, but what he left behind made it clear he intended to kill any of them that crossed his path, said FBI Agent in Charge David L Bowdich.
The gunman's duffel bag contained a handwritten letter signed by Ciancia stating he'd "made the conscious decision to try to kill" multiple TSA employees and that he wanted to "instill fear in their traitorous minds," Mr Bowdich said.
Rep. Michael McCaul, chairman of the House Homeland Security Committee, said on CNN's State of the Union today that he had seen the note and said that what Ciancia "wanted to talk about was how easy it is to bring a gun into an airport and do something just like he did."
The attack underscores how difficult it is to protect travellers at a massive airport such as LAX, where the terminals are open and easily accessible to thousands of people who arrive via a broad ring road that fronts the facility and is designed to move people along quickly.
"It's very difficult to stop these types of attacks," Mr McCaul said. "And you know, it's like a shopping mall outside the perimeter, it's almost like an open shopping mall. So it's very difficult to protect."
The FBI has served a search warrant on a Sun Valley residence where Ciancia lived, said Ari Dekofsky, a spokeswoman for the FBI's Los Angeles field office. Agents are still interviewing people, she said.
Authorities believe the rifle used in the shooting was purchased in Los Angeles. Ciancia also had two additional handguns that he purchased in Los Angeles, but which weren't at the crime scene, a law enforcement official said.
The purchases themselves appeared legal, although authorities were still tracing them, and it's unclear if the shooter used his own identification or someone else's, the official said.
"He didn't buy them on the street. He didn't buy them on the Internet," the official said. "He bought them from a licensed gun dealer - the rifle and the two handguns."
Hernandez, a three-year veteran of the TSA, moved to the US from El Salvador at age 15, married his sweetheart, Ana, on Valentine's Day in 1998 and had two children.
The other two TSA officers wounded in the attack have been released from the hospital.
Brian Ludmer, a Calabasas High School teacher, remained in fair condition at Ronald Regan UCLA Medical Centre with a gunshot wound to the leg.
The FBI was still looking into Ciancia's past, but investigators said they had not found evidence of previous crimes or any run-ins with the TSA. They said he had never applied for a job with the agency.