The longtime treasurer of a volunteer fire department in Loudoun County pleaded guilty Wednesday to stealing more than $645,000 of the organization’s money, which he used to pay off his mortgage and credit card bills and fix his car.

In court documents, Jerry Keith Cromer Jr., 79, admitted that he essentially used the coffers of the Aldie Volunteer Fire Department as his own bank account for more than a decade, writing checks or simply withdrawing money for personal expenses. The theft started in 2000 and continued until September, court filings show.

Cromer pleaded guilty Wednesday to a charge of theft from an organization receiving federal funds in a near-empty courtroom in the federal district courthouse in Alexandria. The court appearance was his first; as part of a deal with prosecutors, he waived his right to be indicted.

Cromer’s plea comes just more than a year after authorities revealed that Middleburg Volunteer Fire Department Treasurer Paul Draisey was suspected of taking almost $500,000 from the organization. Draisey, a popular Loudoun radio personality, killed himself after members of the department’s board started asking questions about the group’s funds.

Loudoun uses paid and volunteer firefighters, and the volunteers are sometimes provided with county funds for new buildings, equipment or other needs, authorities said.

Scott K. York (R), chairman of Loudoun’s Board of Supervisors, said that although board members have no control over the volunteers’ finances, they have tried to push for access to the fire companies’ books when allocating county funds. He said the board also has advised volunteer leaders on appropriate “checks and balances” to prevent theft, such as requiring two people to sign checks from department accounts.

“There are safeguards that we’re trying to make sure are put in place,” York said.

According to court filings, Cromer, of Gainesville, had “sole signature authority” when he served as the elected treasurer of the Aldie Volunteer Fire Department from 1995 to 2012. In 2000, according to the filings, he began writing checks from the department’s accounts to pay his mortgage and Sears, Chase and BP credit card bills.

Robert A. Brown, the department’s attorney, said in an e-mailed statement that the theft came to light during an examination of the department’s finances for tax purposes. The department’s board removed Cromer from office and seized financial records from him in October, Brown said. He said the department was “hopeful that it can recoup most, if not all, of the embezzled funds.”

“On behalf of the Department, we sincerely hope that the members of our community will not let this episode overshadow the Department’s faithful and beneficial service and will continue to look with favor upon its firefighters and first responders,” Brown said in the statement.

Cromer said little of substance during Wednesday’s half-hour hearing, answering most of Judge Gerald Bruce Lee’s questions with a simple “Yes, sir” or “No, sir.” He and his attorney, Shannon Quill, declined to comment afterward.

Lee ordered Cromer released on a personal recognizance bond — although he is on the hook for $100,000 should he fail to appear in court. He faces a maximum penalty of 10 years in prison at his Oct. 11 sentencing, but Quill said in court that federal sentencing guidelines call for a term of a little more than three years in prison, even in a worst-case scenario.