Amy Leigh Mentz, 32, a former employee of Heritage Community Bank of Greeneville, pleaded guilty on Monday in U.S. District Court to a one-count "information" that charged her with embezzlement over $1,000 by an employee of a federally insured bank.

Before entering a guilty plea to the one-count federal information document before U.S. District Judge Ronnie Greer, Mentz waived indictment by a federal grand jury, according to court records.

Judge Greer, after accepting Mentz's guilty plea, scheduled a sentencing hearing for Mentz for 9 a.m. on Oct. 20.

At sentencing, according to the plea agreement, she faces imprisonment of not more than 30 years, a fine of not more than $1 million and a term of supervised probation of not more than five years.

Mentz was employed as a teller by Heritage Community Bank from October 2005 until her termination in June 2007, according to the plea agreement.

"At all times relevant ... Mentz worked at the downtown Greeneville branch and was responsible for managing and balancing the automated teller machine (ATM) at that branch," the plea agreement states.

While investigating a loss at another branch of the bank, according to the plea agreement, Heritage Community Bank officials conducted a count of all cash on June 18, 2007.

Mentz was out sick the day the cash was counted and bank officials waited until the next day (June 19, 2007), to count the cash in the downtown branch, according to the plea agreement.

"After counting the cash in the ATM, a difference of $25,000 was discovered between the cash in the ATM and the general ledger accounts," the plea agreement said. "When she was advised of the shortfall, Mentz first claimed that she may have made an error when she put cash in the ATM the previous week. Mentz then went home sick."

When Mentz returned to work and was terminated two days later, she had "no explanation as to how she could be in balance according to the balancing spreadsheet but have a $25,000 shortage in the ATM," according to the plea agreement.

Further investigation by Heritage Community Bank officials revealed that on March 5, 2007, the amount of money in the ATM decreased by $21,000 but the amount of cash in the bank's vault did not increase.

"The decrease caused a $21,000 difference between the teller system and the general ledger," the plea agreement said. "The following week, Mentz had increased the cash in the ATM and made the correct tickets, but she had also made an additional cash entry for the ATM on the teller system. This action had the effect of canceling the entry from March 5, but the ATM was still short $21,000."

Both of the "phantom entries" were "covered up by manipulating the formulas on the teller cash totals spreadsheet," according to the plea agreement.

"As a result, there were no cash differences shown when such differences, in fact, existed," the plea agreement said.

Mentz was interviewed by FBI special agents on Feb. 29, 2008, and "admitted embezzling approximately $21,000 from HCB," according to the plea agreement.

"Mentz said she started taking money in $500 increments beginning in late 2006," the plea agreement said. "She began taking larger increments of $1,000 and adjusted the ATM amounts accordingly to conceal her embezzlement."

The plea agreement also said Mentz told FBI agents that she had intended to repay the money, but her actions "quickly spiraled out of control," according to the plea agreement.

She used the money to pay bills and purchase some items for her daughter, according to the plea agreement.

"Mentz provided a written statement setting out what she had done and expressing remorse," the plea agreement said.