Marilyn Hartman, 62, was taken into custody after officers spotted her at 10:20 a.m. boarding a FlyAway bus at Union Station in downtown Los Angeles and then getting off at LAX, airport police Chief Patrick Gannon said.
Gannon said he believed she would return — and she did, possibly on a scouting mission. Fliers with her photograph on them had been distributed to airport police and staff because they thought she might try to make another attempt, he said.
"It's a big deal when anyone tries to avoid security, be it a 62-year-old grandmother or a 24-year-old terrorist," he told The Times.
After getting off the bus, Hartman entered Terminal 2 and wandered for an hour through three different terminals. But Gannon said Hartman had no intention of purchasing a ticket, even though she had enough money to do so.
"Not in my backyard she's getting on a plane without a ticket," Gannon told The Times.
Hartman made headlines this week when it was discovered that she had somehow bypassed two boarding pass checkpoints at Mineta San Jose International Airport and boarded a Southwest flight to L.A.
Hartman got off the plane at LAX, where she was arrested for trespassing. On Wednesday, she pleaded no contest and promised to not return to the airport without a ticket. She said that what she did was "stupid" and that she planned to take a bus back to the Bay Area.
Hartman is already banned from San Francisco International Airport after allegedly attempting to board planes there multiple times without a ticket.
Times staff writers Kate Mather and Richard Winton contributed to this report.