Nna Alpha Onuoha, 29, had resigned his job with the Transportation Safety Administration at the airport before his arrest, the Los Angeles Times reported Wednesday.
FBI spokeswoman Laura Eimiller said Onuoha was arrested before midnight in Riverside by members of the Joint Terrorism Task Force and the Riverside police force.
Eimiller said Onuoha had resigned his position Tuesday after a recent suspension and left a suspicious package for another TSA employee at the airport. The Los Angeles police department bomb squad determined the package was not dangerous but found an eight-page letter in which Onuoha mentioned the incident that led up to his suspension and his disdain for the United States.
Later that day, Eimiller said, a man the FBI believed to be Onuoha called the TSA and told an employee to evacuate "certain terminals at the airport." A person believed to be the same man called the TSA a second time and again instructed that terminals be evacuated.
The terminals were closed and searched, but no threat was found, the spokeswoman said.
A search of Onuoha's apartment found a note containing "an unspecified threat citing the 9/11/13 anniversary," she said.
Officials said two other suspicious packages believed to have been sent by Onuoha were intercepted Wednesday, NBC-TV, Los Angeles, reported. The second package arrived at the Inglewood Veteran's Facility where Onuoha had been living, and a third was sent to a TSA office on Century Boulevard near LAX airport, causing the office to be temporarily evacuated, the TV station said.
The FBI said it expects more packages will be found.
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