(CNN) -- Bail was set at $50,000 Friday night for a GOP campaign worker who made up a story about being attacked by a man angered by a John McCain bumper sticker on her car.

Police say Ashley Todd admitted making up the report that she was attacked because of a McCain sticker.

Ashley Todd, 20, of College Station, Texas, has been charged with filing a false police report, a misdemeanor, a police report said.

Todd, who is being held at the Allegheny County Jail in Pittsburgh, Pennsylvania, did not enter a plea when she appeared in court Friday night. She did not post bail.

She is scheduled to appear in court again October 30, when she is expected to enter a plea.

If she posts bail, Todd must be evaluated at a behavioral clinic.

"This has wasted so much time. ... It's just a lot of wasted man hours," Assistant Police Chief Maurita Bryant said at a briefing.

Todd was a volunteer for a John McCain phone bank in Pittsburgh, the campaign said.

The woman told investigators a man approached her Wednesday night at an ATM in Pittsburgh's East End, put a blade to her neck and demanded money, said Pittsburgh police spokeswoman Diane Richard.

Police said they found "several inconsistencies" in Todd's statement and she was not seen in surveillance videos taken at the ATM. She was asked to take a polygraph test Friday morning, Richard said. The results were not made public.

Later, Todd came to the police station to help work on a composite sketch of the alleged attacker. When she arrived, Todd "told them she just wanted to tell the truth" -- that she was not robbed, and there was no attacker, Bryant said.

Todd originally told police a man "punched her in the back of the head, knocking her to the ground, and he continued to punch and kick her while threatening to teach her a lesson for being a McCain supporter," according to a police statement.

The woman also told police her attacker "called her a lot of names and stated that 'You are going to be a Barack supporter,' at which time she states he sat on her chest, pinning both her hands down with his knees, and scratched into her face a backward letter 'B' on the right side of her face using what she believed to be a very dull knife."

Bryant described Todd as "very cordial, polite, cooperating," and said the woman was surprised by all the media attention. Asked whether the false report was politically motivated, Bryant replied, "It's difficult to say."

"She is stating that she was in her vehicle driving around, and she came up with this idea," she said. "She said she has prior mental problems and doesn't know how the backward letter 'B' got on her face."

However, Todd was the only one in the vehicle, and "when she saw the 'B' she thought she must have been the one who did it," Bryant said.

"We're talking with the district attorney's office and conferring on just how we're going to handle it," she said. "It's been different stories through the night and this morning."

She said there was no indication that anyone else was involved.

Richard said the woman had described her alleged attacker as an African-American, 6 feet 4 inches tall with a medium build and short dark hair, wearing dark clothing and shiny shoes.

Before the revelation that the report was false, McCain spokeswoman Jill Hazelbaker said that McCain and running mate Alaska Gov. Sarah Palin "spoke to the victim and her family after learning about the incident."

The Obama campaign also had issued a statement wishing the woman a "speedy recovery."

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