For years, co-workers and supervisors looked up to Vernita M. Greenfield, a D.C. government dispatcher who worked so many hours that she regularly handled more tow-truck orders to hook and haul vehicles than any colleague at the Department of Public Works, according to court files.

However, her labors only deepened an entrenched “culture of corruption” at the giant city agency, according to federal prosecutors, as the veteran dispatcher raked in more than $35,000 in bribes between July 2011 and May 2013 to steer more than 450 calls to a favored vendor.

[2004: U.S. indicts D.C. DPW parking enforcers]

Court documents did not identify the company that paid Greenfield $200 to $500 in weekly installments to throw it towing orders. But prosecutors said numerous department workers and several competitors among the roughly two dozen department-approved towing vendors “had complained about Ms. Greenfield’s actions to DPW’s management in the past, to no avail.”

On Tuesday, U.S. District Judge Paul L. Friedman sentenced Greenfield, 57, of Washington, to three years of probation and ordered her to forfeit $35,300. In May, she pleaded guilty to one federal bribery count.

Greenfield, who was a customer-service representative for the Parking Enforcement Management Administration, also was ordered to serve three months in a halfway house and three months under curfew with GPS monitoring and to perform 150 hours of community service.

“To the extent that her conduct of accepting bribes was known throughout the DPW office, Ms. Greenfield’s actions set a tone for corruption in the office,” Assistant U.S. Attorneys Lionel Andre and Mervin Arthur Bourne Jr. wrote. They had sought a two-year prison sentence for Greenfield.

They added: “DPW has dealt with a culture of corruption and bribery for many years. It is important that the sentence in this case reflect that the courts take the bribery of public officials seriously, and protect the public.”

[1998: 10 DPW car inspectors charged in corruption case]

[2000: Road builders indicted on corruption charges with DPW]

Linda Grant, a DPW spokeswoman, said the department “takes our responsibility to fairly distribute towing duties among District towing operators very seriously.”

In a court filing unsealed Wednesday, Greenfield’s attorney, Charles Canty, wrote that “there was no harm to anyone in this case except for the defendant and her family,” adding that Greenfield is ill and that the tow company’s owner “escaped prosecution and remains unscathed.” The crime did not inconvenience customers, cost taxpayers extra or put vendors out of business, Canty wrote in seeking probation for Greenfield.

A shift change at DPW caused Greenfield to give up a second job in 2011, when she was approached by a tow company’s owner, Canty said in the filing. Greenfield used the money “in large part” to pay for a daughter’s education and help an ailing mother and “not for personal self-enrichment,” he wrote.

Court filings stated that the favored tow company is in the 1700 block of Adams Mill Rd. NW in Washington and identified its owner only by his initials. An employee of a tow company in that block referred questions to its owner, who did not immediately respond to a message left Wednesday morning.