Former Field Museum worker Caryn Benson admitted in federal court Monday to stealing more than $400,000 from her longtime employer, but the U.S. attorney's office contended the amount was over $900,000.



Benson, 38, of Chicago, faces a possible sentence of up to 37 months in prison, according to the government's recommendation in a plea agreement entered before Judge James Zagel in U.S. District Court.



Wearing a winter coat with a fur or faux-fur collar as she stood before Zagel, Benson quietly answered "yes" to the judge's series of questions about whether she understood the implications of her admissions. She was freed on bail with a sentencing set for Aug. 25; her lawyer contends the sentence should be in the range of 18 to 24 months.



Benson, who worked at the Field Museum from 2003 to 2014 and whose last job was as a data records supervisor in the membership department, acknowledged pocketing cash payments that some museum patrons made for memberships between June 2008 and April 2014. She also admitted to, during that period, keeping cash patrons paid for drink tickets at special events at the natural history museum, such as the regular members' nights.



In the deal, Benson pleaded guilty to one count of embezzlement charging her with taking $33,014 during the first four months of 2014. That's when an internal audit discovered missing money and she was fired, museum officials have said, and a subsequent "forensic audit" discovered some $903,000 missing from museum coffers. That is also the amount the government said she owes in restitution — the $33,014 she was charged with taking plus an additional $870,270.



But her lawyer, Anthony Sassan, said Monday the amount Benson acknowledges pocketing is substantially less — the $33,014 in the charge and an additional $376,986 she acknowledged embezzling in the plea agreement.



The U.S. attorney's office would not comment further or explain the discrepancy. There will be a "pre-sentence investigation," Zagel said in court.



Sassan, however, said after the morning proceeding that the $410,000 figure was in line with a review of his client's financial records and that other employees could have taken money from the museum the same way that Benson did.



"The system in place would make it easy for others to do it," he said, emphasizing that he was not making a specific accusation. He added that funds missing from drink ticket sales would be much more difficult to trace than missing membership money, which may further explain some of the difference.



In any case, "the money's spent" ... on "living expenses and children," Sassan said. He said Benson has a teenage daughter and an adult daughter. Zagel granted Benson permission to travel to Virginia to visit the adult daughter later this month.



As the Field had stated in admitting to the financial loss in a December federal tax filing, the museum remains confident that Benson acted alone, Chief Marketing Officer Ray DeThorne said Monday.



He expressed confidence in the $903,000 figure, saying it was confirmed in the Field's own audit and in one conducted by the museum's insurance company before it made restitution to the museum, less a $10,000 deductible.



"They were able to find memberships that didn't have any money associated with them over a seven-year period," said DeThorne, adding that auditors also found one membership event from which $25,000 in cash in drink-ticket sales was missing.



The museum has since put into place much stricter oversight over cash transactions, he said.