Metropolitan Police yesterday arrested a former D.C. firefighter who, sources said, told investigators about a sex ring being operated by fire department employees. Darryl Green, 42, of the 1200 block of Longfellow Street in Northwest, turned himself in at 6:30 a.m. yesterday after a warrant was issued for his arrest for indecent exposure. Fire officials said they are taking the charges seriously, and last week Mr. Fenty, Metropolitan Police Chief Cathy L. Lanier and Fire Chief Dennis L. Rubin held a press conference to discuss the investigation. Mr. Green was a sergeant in the fire department until last month, when he resigned after a July 30 incident in which he exposed himself to a female emergency medical technician in the lounge area of Engine 8 at 1520 C St. SE. “This arrest was a result of the quick work by our new internal- affairs task force and interagency cooperation between our hardworking fire and police departments,” Mr. Fenty said. “There is nothing more important than maintaining the public trust and we will continue to work to ensure that our public safety agencies remain departments the residents of the District of Columbia can be proud of.” “The Metropolitan Police Department cannot release the details about the incident that led to Mr. Green being charged,” said spokeswoman Traci Hughes. Miss Hughes declined to say whether the incident Mr. Green was charged in connection with took place while he was on duty. Sources told The Washington Times that during the course of the investigation Mr. Green told officials about sexual misconduct within the department. The officials confirmed that they are looking into claims of sexual misconduct, which could result in criminal charges, but declined to discuss what the claims were. A police spokeswoman said the investigation is ongoing but could not provide further details yesterday. Fire officials last week confirmed that they are also investigating three cases in which female emergency medical technicians say Mr. Green offered them lucrative overtime assignments in exchange for sex. However, a news release issued by Mayor Adrian M. Fenty’s office said Mr. Green was arrested in connection with an event that occurred July 6, 2006. Sources say among the charges Mr. Green made, was that female emergency medical technicians performed sex acts for money on men, including male fire department employees, in the bunkhouses of fire stations since late last year. The prostitution may have also occurred at other locations.The sources say the ring was referred to as “D.C. Fems” – a play on the acronym for the city’s Fire and Emergency Medical Services department.