(FOX NEWS) -- Federal prosecutors announced Saturday that they have filed charges of murder and commission of violence at an international airport against the man suspected of carrying out the deadly shooting at Los Angeles International Airport in which a TSA officer was fatally shot, and several others were wounded.
If convicted, 23-year-old Paul Anthony Ciancia could get the death penalty. He was arrested Friday after authorities say he barged into a terminal, pulled an AR-15 semi-automatic rifle from his duffel bag and opened fire. The bullets killed a Transportation Security Administration officer and injuring four others before Ciancia was gunned down by airport police.
The killing was "believed to be a premeditated act of murder in the first-degree," U.S. Attorney Andre Birotte Jr. said in announcing the charges.
The announcement comes after authorities say they have found a note handwritten by Ciancia in which he describes his intent to kill TSA employees and "pigs," a law enforcement official told The Associated Press.
Federal authorities said Ciancia had "a bunch of threatening language directed at the TSA and lots of anti-government rants."
The note found in Ciancia's duffel bag reportedly suggested the unemployed motorcycle mechanic was willing to kill almost any officer he could find.
"Black, white, yellow, brown, I don't discriminate," the note read, according to a law enforcement official who spoke to the Associated Press.
The suspect's screed reportedly also mentioned "fiat currency" and "NWO," possible references to the New World Order, a conspiracy theory that foresees a totalitarian one-world government.
The exact motive for the shooting remains unclear. But an eyewitness claim may support authorities' theory thus far.
Leon Saryan, 65, had just passed through security when he heard gunshots. He fled with a TSA worker, who he said was later wounded slightly, and managed to hide in a store. As he was cowering in the corner, the shooter approached.
"He looked at me and asked, 'TSA?' I shook my head no, and he continued on down toward the gate. He had his gun at the ready and but for the grace of God I am here to tell about it," said Saryan, of Milwaukee.
Los Angeles Mayor Eric Garcetti said the gunman had an additional 100 rounds of ammunition he did not fire.
A law enforcement official who was not authorized to discuss the investigation publicly and spoke on condition of anonymity, said the note referred to how the gunman believed his constitutional rights were being violated by TSA searches and that he was a "pissed-off patriot" upset at former Homeland Security Secretary Janet Napolitano.
Ciancia's family had told Pennsville, N.J. Police Chief Allen Cummings early Friday afternoon that the 23-year-old had mentioned taking his own life in a text message to his younger brother, the chief told The Associated Press.
Cummings notified the LAPD, which in turn, went to Ciancia's residence. He was not there at the time, but his two roommates told authorities that he seemed fine, Cummings said. LAPD told Cummings that they would check on him again when Ciancia returned from work.
Forty-five minutes later, Cummings got a call about the shooting.
The TSA late Friday identified the deceased officer as Gerardo I. Hernandez, 39. He is the first TSA officer killed in the line of duty in the 12-year history of the agency, which was founded in the aftermath of 9/11.
The FBI said had not yet interviewed Ciancia about the shooting because he was still hospitalized but expected to speak with him as soon as possible. He was shot four times by airport police.
Airport officials say LAX's Terminal 3 is open as of early Saturday afternoon.
The suspect graduated in 2008 from Salesianum School, an all-boys Roman Catholic school in Wilmington, the school said.
Outside the father's home Friday in Pennsville, a police cruiser blocked the long driveway. Phone calls weren't answered, and efforts to reach siblings were also unsuccessful.
The shooting, which sent passengers in the airport scrambling for cover, disrupted flights nationwide as planes headed for Los Angeles were temporarily grounded. LAX estimated 1,550 scheduled flights were impacted by the shooting and approximately 167,050 passengers were affected, including those diverted to other airports, held on the ground in Los Angeles or held at their originating airport.
Dr. David Plurad of the Harbor-UCLA Medical Center said the officer who was killed had suffered severe gunshot wounds to his chest and abdomen along with a "significant" blood loss.
Los Angeles Fire Department Battalion Chief Armando Hogan said five people were taken to hospitals after the shooting: the gunman, the TSA officer who died, two other people who were shot, and one person with a broken ankle. A sixth person was treated at the scene for ringing in the ears from gunfire. The TSA said both surviving shooting victims are TSA officers.
The attack began around 9:20 a.m. when the gunman pulled an assault-style rifle from a bag and began firing inside Terminal 3, Airport Police Chief Patrick Gannon said.
Officials said the gunman pulled an assault rifle out of a bag on the ground floor of the terminal and opened fire. He ran up an escalator to a TSA screening area and continued to fire, officials say. He was tracked by airport police and they engaged in gunfight until the suspect was subdued, officials said.
Witness Brian Keech said he heard "about a dozen gunshots" from inside the security gate at Terminal 3. Other travelers described the scene as airport security staff evacuated terminals, including onto to the tarmac.
"People started saying there's a shooter, there's a shooter," said Natalie Morin, a senior at USC who was heading to San Francisco for a graduate school interview.
President Obama called Pistole to express his condolences to the families and friends of the TSA officer who was killed and the two other officers who were wounded Friday.