LOS ANGELES — Moments after gunfire broke out at the Los Angeles airport, Paul Ciancia’s father called police in New Jersey, worried about his son in LA.
The young man had sent texts to his family that suggested he might be in trouble, at one point even saying goodbye.
The call came too late. Ten minutes earlier, police said, the 23-year-old unemployed motorcycle mechanic had walked into LAX, pulled an AR-15 semiautomatic rifle from his duffel bag, and began firing at Transportation Security Administration officers.
When the shooting stopped, one TSA officer was dead and five other people were wounded, including two more TSA workers and the gunman himself.
Ciancia’s exact motives were not clear, but he had some kind of beef with the TSA: A note in his bag said he would be happy if he managed to kill just one TSA agent. ‘‘Black, white, yellow, brown, I don’t discriminate,’’ the note read, according to a paraphrase by a law enforcement official briefed on the investigation.
The screed mentioned ‘‘fiat currency’’ and ‘‘NWO,’’ possible references to the New World Order, a conspiracy theory about a totalitarian one-world government.
By all accounts, Ciancia was reserved and solitary. Former classmates barely remember him, and even a recent roommate could say little about the young man who moved from New Jersey to Los Angeles less than two years ago.
When police stopped him, Ciancia had five 30-round magazines, and the bag contained ‘‘hundreds of rounds in 20-round boxes,’’ the official said.
Authorities identified the dead TSA agent as Gerardo I. Hernandez, 39, who became the first TSA official in the agency’s 12-year history to be killed in the line of duty.
Ciancia, who was shot four times by police, remained hospitalized Saturday, but there was no word on his condition. He was wounded in the mouth and a leg, authorities said.
Allen Cummings, the police chief in Pennsville, a small blue-collar town near the Delaware River where Ciancia grew up, said he’s known Ciancia’s father — also named Paul — for more than 20 years.
He said the father called him around 12:30 p.m. Friday to tell him about texts his family had received from his son in Los Angeles.
‘‘There was some things in there that made his family feel he may do harm to himself,’’ Cummings said. He did not mention suicide or hurting others, but he did say goodbye.
Cummings said the father also heard from a friend that his son may have had a gun.
The chief said he called Los Angeles police, who sent a patrol car to Ciancia’s apartment. There, two roommates said that they had seen him a day earlier and he had appeared to be fine.
Cummings never met Paul Ciancia Jr., but he learned from his father that he attended a technical school in Florida, then moved to Los Angeles in 2012 hoping to work as a motorcycle mechanic. But he was having trouble finding a job, the chief said.
Hernandez was one of the TSA’s behavioral detection officers, who are stationed throughout the airport looking for suspicious behavior, said J. David Cox Sr., national president of the American Federation of Government Employees.
Friends and neighbors remembered the Los Angeles man as a doting father of two and a good neighbor who went door-to-door warning neighbors to be careful after his home in the Porter Ranch area of Los Angeles was burglarized.
It was not the first shooting at LAX. On July 4, 2002, a limousine driver opened fire at the airport’s El Al ticket counter, killing an airline employee and a person who was dropping off a friend at the terminal. Police killed the gunman.