The woman posted a message on Craiglist.org that she was new in town, looking for someone to talk to, and she offered an e-mail address.

About 10 of the men who responded to her message wound up making arrangements to meet her in a Franklin Road motel room and pay for sexual services.

And when they came to the room and showed her the money, they found out she was an undercover Roanoke police officer.

Over the past two years, police departments across the country have begun using the popular online classified ad site to conduct such stings, in part as a reaction to allegations that Craigslist has become a way for prostitutes and customers to connect.

In February, the Roanoke Police Department joined their ranks. While having an undercover officer pose as a prostitute to conduct what's called a "reversal sting" is not anything new in Roanoke, Assistant Roanoke Commonwealth's Attorney Sheri Jones says this particular sting is the first involving Craigslist.

Roanoke police spokeswoman Aisha Johnson would say only that police set up the sting to look for illegal activity on the site and that the department might conduct similar stings in the future. Police declined to discuss any further details of the operation, including exactly how many men were arrested.

But some details about how the stings were conducted came out this week after one of the men who responded to the message pleaded no contest to a misdemeanor charge of soliciting prostitution.

Alfred Lee Hannah Jr., a former government teacher at Hidden Valley High School, agreed via e-mail to meet the woman at the Quality Inn on Franklin Road and pay $150 for sexual services, prosecutors said.

On Feb. 20, he went to the room, told the officer what act he wanted to perform with her and counted out the money for her. She went into the bathroom, supposedly to change clothes, and officers waiting in another room came in and arrested him, Jones said.

Hannah, who was in court Thursday morning, has not been found guilty of the charge. A Roanoke General District Court judge postponed any decision about his guilt until his sentencing Aug. 18.

Hannah, who now lives in Alabama, faces a maximum possible punishment of 12 months in jail. His attorney, Greg Phillips, said that though Hannah recalls events differently from how authorities present them, "He made a huge mistake that's totally out of his character."

Law experts say a sting like the one Roanoke police conducted can raise questions about entrapment -- whether police deliberately egged somebody on to commit an act they normally would never commit. Jones said the e-mail exchanges were conducted so that the men would ultimately volunteer to the officer what they expected from the hotel meeting, rather then her suggesting it to them.

Both University of Virginia law professor Anne Coughlin and Radford University criminal justice professor Tod Burke noted that the sting also potentially raises a question of resources. As Coughlin phrased it, "Why are the police in our town using their resources to do this as opposed to combating some other kind of crime?"

In 2006, police in Bensalem, Pa., were among the first to conduct a prostitution sting using Craigslist. In their sting, officers posed as customers and made arrangements to meet and arrest women selling sexual services on the site.

Bensalem Deputy Director of Public Safety Pat Ponticelli said the public safety department received a number of accolades for its efforts, which didn't require them to reduce their efforts in other areas of law enforcement. "It's forward thinking on our part," he said.

He said police are just trying to keep up with the latest tools criminals use. Craigslist can be a temptation for people looking to sell all sorts of things illegally because, "It's open, it's out there, and it's free."

Susan MacTavish Best, a spokeswoman for Craigslist, wrote in an e-mail that the site is providing assistance every day to police and federal authorities.

"Criminals using Craigslist leave an electronic trail to themselves, a trail that law enforcement officers will follow immediately," she wrote. "Given that, Craigslist is truly an unwise choice for those intent on committing a crime."

Staff writer Amanda Codispoti contributed to this report.