SANTA MONICA, Calif. -- Just before Lindsay Lohan's arrest, the mother of her former personal assistant made a 911 call asking for help because a mysterious car was following her -- unaware that Lohan was behind the wheel, according to an audio copy released Thursday.

Lohan's personal assistant quit hours before the incident, police said.

The caller apparently did not know that Lohan was driving the vehicle that was following her when she talked with a Santa Monica police dispatcher shortly after 1:30 a.m. Tuesday.

"We were just about to park our car. We are turning home and out of nowhere a huge white GMC came up," the woman said to the dispatcher. Unintelligible remarks apparently to the woman's passenger can also be heard in the recording.

"We're being followed by a GMC ... the gentleman jumped out of the car," she added a few seconds later. "Oh my God, sir, they're following us. We need help."

According to police, the woman drove her vehicle into the parking lot of Santa Monica's Civic Auditorium, and was followed into the lot by Lohan in a Yukon sport utility vehicle.

When police arrived, the woman pointed out Lohan's vehicle as the one that had been following her.

Authorities also found Lohan and the woman who called 911 in what they are calling a "heated debate." Police also said two men were with Lohan in the vehicle.

Lohan was arrested for investigation of misdemeanor driving under the influence and with a suspended license, and felony cocaine possession.

Late-Night Comedians Pile On

Forget what Barbara Walters thinks: The late-night talk-show circuit is having a field day in the aftermath of Lohan's most recent arrest.

Walters criticized Jay Leno and his guest Rob Schneider on "The View" Wednesday for mocking Lohan, who was arrested early Tuesday.

The 21-year-old actress was less than two weeks out of rehab when she was arrested.

Lohan was scheduled to appear on Leno's show Tuesday night but dropped out, so Schneider filled in, showing up in black dress, blonde wig and an "ankle bracelet" filled with "alcohol."

On Wednesday, David Letterman noted that Lohan said the cocaine police found in her pocket isn't hers, and said, "Finally, an Oscar-worthy performance."

Also alluding to Lohan's arrest, Letterman said, "Your move, Paris."

Leno took more shots at the actress Wednesday night, saying that it's so hot in Los Angeles, he's sweating like Lohan's insurance agent.

Leno added that the Lohan case is full of surprises.

He said the real shock was that the car Lohan was chasing was being driven by Britney Spears' kid.

Will Rehab Prevent Jail Time?

If Lohan wants to avoid jail time, legal observers said she needs to go back into rehab a third time this year -- and stop partying.

Her arrest Tuesday on suspicion of DUI was her second in three months.

Lawrence Taylor, a former Los Angeles prosecutor, said that if Lohan is convicted of two felonies in the Beverly Hills and the Santa Monica cases, she might be eligible for 18 months or more in state prison -- but added that kind of sentence is unlikely.

Over the weekend, Lohan was photographed at a party in a pink bikini with an alcohol-monitoring device on her ankle.