Security will be reviewed at Los Angeles International Airport and at other airports across the nation following last week's deadly shooting at the sprawling facility, Attorney General Eric Holder said Monday.
Holder also said that investigators were looking more deeply into what led the alleged gunman to target Transportation Security Administration officers in the Friday attack, which left one officer dead.
A rambling message was found among Paul Ciancia's belongings, which allegedly expressed extreme anti-government sentiments and intentions to target TSA personnel.
Holder said there was a need for "a fuller understanding'' of what prompted the fatal shooting in which Ciancia also was wounded.
"Whatever the motivations, it certainly does not justify these kinds of actions,'' Holder said. Ciancia, 23, was shot by airport police and remained hospitalized under heavy guard Monday.
The FBI said he had a handwritten letter, stating that he made the conscious decision to try to kill multiple TSA officers and "instill fear in your traitorous minds."
The unemployed motorcycle mechanic who recently moved to Los Angeles from the small, blue-collar town of Pennsville, N.J., had a friend drop him at LAX on Friday just moments before he pulled a .223-caliber assault rifle from his duffel bag and opened fire. In addition to the one TSA fatality, three people were wounded, including two TSA workers.
Officials do not believe that the friend knew of the shooter's plans.
Ciancia, who faces charges of murder of a federal officer and committing violence at an international airport, could be sentenced to death if convicted.
Ciancia is accused of walking into the airport's Terminal 3, pulling the assault rifle from a duffel bag and firing repeatedly at 39-year-old TSA officer Gerardo Hernandez. Ciancia went up an escalator, turned back to see Hernandez move and returned to shoot him again, according to surveillance video reviewed by investigators.
He then fired on two other uniformed TSA employees and an airline passenger, who all were wounded, as he moved methodically through the security checkpoint to the passenger gate area before airport police shot him as panicked travelers hid in stores and restaurants.
Investigators recovered a rambling message from the bag the suspect was carrying, which detailed an intent to "kill'' TSA officers,'' two federal law enforcement officials said. It also referred to an "NWO," or new world order, and identified the TSA as an intended target.
The officials, who are not authorized to comment publicly but who was familiar with contents of the message, said it was written in way that the author expected his own life to be taken in the incident.
"This was clearly a suicide mission,'' one of the officials said. "He did not expect to walk away from this.''
The suspect, who was shot in the face, survived an exchange of gunfire with police.
In recent days, according to one of the officials, the New Jersey family of the suspect had become worried about his emotional well-being and called local police who relayed those concerns to Los Angeles authorities.
The official said Los Angeles police reportedly made contact with the suspect's roommates who indicated that Ciancia appeared to be okay.
A federal law enforcement official said the assault-type rifle used in the airport attack is believed to have been purchased legally from a Los Angeles area dealer.
More than 100 rounds of ammunition were recovered from a bag the suspect is alleged to have carried into the airport.
TSA Administrator John Pistole said the agency will need to work with each airport's police agency "to see how we'll go about in providing the best possible security."
The shooting temporarily halted traffic at the nation's third-busiest airport, stranding thousands of passengers and causing dozens of flights to be diverted to other airports. More than 1,500 flights and 167,000 passengers were affected nationwide, according to the Los Angeles Times.
The FBI has served a search warrant on a Sun Valley residence where Ciancia lived, Ari Dekofsky, a spokeswoman for the FBI's Los Angeles field office, said Sunday. Agents are still interviewing people, she said.
Hernandez, a three-year veteran of the TSA, moved to the U.S. from El Salvador at age 15, married his sweetheart, Ana, on Valentine's Day in 1998 and had two children.
The TSA said the other two officers wounded in the attack — James Speer, 54, and Tony Grigsby, 36 — were released from the hospital.
Brian Ludmer, a Calabasas High School teacher, remained in fair condition at Ronald Reagan UCLA Medical Center and will need surgery for a gunshot wound to the leg. Two other people suffered injuries trying to evade the gunman, but weren't shot.
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.
Contributing: Associated Press