By CHAO XIONG and PAUL WALSH Star Tribune staff writers

Two men were each sentenced Monday in Ramsey County District Court to more than 21 years in prison for sex trafficking two vulnerable teens in 2012.

And in a second sex-trafficking case, a Duluth ex-convict was found guilty of selling a girl for sex for many months last year in Minnesota and elsewhere through Backpage.com.

In the first case, Timothy D. Cross, 20, of St. Paul, received 21 years in prison on convictions of aiding and abetting sex-trafficking of someone under 18 and aiding and abetting sex-trafficking of an individual. He was also sentenced to five years for possession of a firearm by an ineligible person. That sentence will run concurrently with the 21 years.

The second man, Fonati Diggs, 24, of Northfield, received 23 years in prison for aiding and abetting sex-trafficking of someone under 18 and aiding and abetting sex-trafficking of an individual.

Ramsey County District Court Judge Lezlie Ott Marek told both that they received the sentences due to the "shocking" nature of their crimes.

Diggs lured an ex-girlfriend, then 18, from Duluth to St. Paul. The woman brought a friend, then 16. Both were raped by the defendants and their friends and trafficked on the streets. The 16-year-old called 911 the second day she was in St. Paul. The woman stayed a week.

"We believe these are the longest sentences for sex trafficking in Minnesota to date," Ramsey County Attorney John Choi said in a news release.

In the second sex-trafficking case, Duluth ex-convict Markeace Canty, 33, was convicted by jurors in federal court in Minneapolis on two counts involving sex trafficking of a minor. He was acquitted of receiving child pornography.

According to prosecutors, Canty bought "escort" ads on Backpage.com from July 2012 until January and offered the girl for erotic encounters. The ads sometimes included photos of a girl no older than 17.

The indictment against Canty said he also bought a Backpage escort ad in northwestern Indiana in September. That caught the eye of authorities, who set up a sting at a motel in Valparaiso, where the girl offered sex for $200 an hour and was arrested.

Also convicted in state court involving the same acts was Tabbatha L. Olson, 23, of Duluth. Olson, who was charged with aiding and abetting sex trafficking, is scheduled to be sentenced in St. Louis County District Court on Oct. 3. The county attorney's office said at the time of charging that Canty and Olson were involved in the trafficking of several females.

cxiong@startribune.com • 651-952-5034 pwalsh@startribune.com • 612-673-4482