Nov. 1, 2013 -- The alleged Los Angeles International Airport gunman carried a note with him today that expressed anti-government sentiments and suggested he expected to die in an airport shootout, according to law enforcement sources.

The suspect has been identified by the FBI as Paul Ciancia, 23. He is believed to have homes in Los Angeles and Pennsville, N.J.

The note found at the scene ended with the letters "NWO," according to law enforcement sources, which is believed to stand for "New World Order." Law enforcement sources also said a large number of .223 caliber rounds were found at the airport.

Officers followed Ciancia to the rear of Los Angeles International Airport's Terminal 3, where he was shot and taken into custody, according to Mayor Eric Garcetti.

David Bowdich of the FBI said Ciancia is receiving medical attention at a hospital.

The TSA confirmed the identity of the officer killed as Gerardo I. Hernandez, 39, who has been with the TSA since 2010.

Suspect's Family Feared He Was Suicidal

Earlier today, Ciancia's father contacted police in Pennsville, N.J., with the concern that his son may be suicidal, Chief Allen Cummings of the Pennsville Police Department told ABC News.

"Their younger child got a text message from Paul stating that there were some comments in there about his wellbeing and he wanted to possibly take his own life," Cummings said.

Cummings said he called the LAPD today and asked for officers to "try to get a well-being check" on Ciancia.

Officers went to Ciancia's apartment before the shooting and talked to his roommates, Cummings said.

Around the time of the shooting, LAPD officers called Cummings, unaware that Ciancia was the gunman, to let him know that they had satisfactorily completed the well-being check.

Authorities said they believe Ciancia acted alone, however they will investigate whether he has any ties to domestic terrorists.

Los Angeles World Airports Police Chief Patrick Gannon said the shooter was armed with an assault rifle, blasted his way past airport screeners and "got back very far into the terminal." Gannon said the shooter initially opened fire before "proceeding up into the screening area" where he shot at TSA officers.

Police "tracked him through the airport... and engaged him in gunfire," Gannon said, eventually taking him into custody.

One TSA officer was fatally wounded, while several others were hit by gunfire.