Kansas City, Mo. ? A Wichita, Kan., man convicted of raping women who advertised in the “erotic services” section of Craigslist was sentenced Thursday to 29 years in prison.

David Lee Gage, 51, was convicted in Sedgwick County, Kan., last month of three counts of rape, two counts of aggravated criminal sodomy, one count of aggravated robbery and one count of aggravated assault.

According to prosecutors, he met the women at motels, then flashed a federal marshal’s badge and threatened to arrest them for prostitution if they didn’t have sex with him.

Assistant Sedgwick County prosecutor Justin Edwards said he believes there were other victims over the years, although the three women who testified against Gage were raped in a 10-week span between May 23 and Aug. 1, 2008.

“In 1998, he was convicted of false impersonation of a police officer and promoting prostitution,” Edwards said in a telephone interview. “He used the same ruse and unfortunately for him he was caught by an undercover police officer” who was working a prostitution sting.

Gage’s attorney, public defender Quentin Pittman, did not return a phone call seeking comment.

Sedgwick County District Attorney Nola Foulston said one of the biggest hurdles in prosecuting the case was convincing the victims that they could trust police officers — people the women usually avoided because of their occupations.

“With these women, part of the problem is they thought he might be a rogue law enforcement officer, and they thought law enforcement wouldn’t listen if it was one of their own,” Foulston said. “This dispels the myth about sexual assault involving these women in these circumstances.”

Jim Buckmaster, CEO of the San Francisco-based online classified service, expressed sympathy for the victims Thursday while noting that Gage had committed the same crime a decade earlier, “long before Craigslist came to Wichita.”

Buckmaster met earlier this month with attorneys general from Missouri, Illinois and Connecticut who pressed him to do something about ads on Craigslist that they believed solicited illegal sexual activity. Those talks came after the April 14 killing of a New York woman who had advertised on the site.

Foulston said Gage could be freed in 24 years, with good behavior, and will have to register as a sex offender.