DNA taken from a 12-year-old St. Paul girl's aborted fetus nearly 10 years ago has led to a guilty plea by the man who raped her while she was being prostituted by her mother.

Walter R. Barbour, 47, pleaded guilty Wednesday in Ramsey County District Court to first-degree criminal sexual conduct for raping the girl in 2002. Barbour remains jailed pending sentencing on May 16.

A criminal complaint filed in October laid out the investigation from the time police were first told of the girl's pregnancy in May 2002 until Barbour was tracked down in late 2011 living in a halfway house in Kansas City, Kan., while on probation after a federal conviction.

Police were notified in May 2002 that the girl was six to eight weeks pregnant and didn't know who impregnated her. Five months later, investigators learned that the girl's mother had been prostituting her since she was 10 in return for drugs and money.

In June 2002, police obtained blood from the girl and tissue from the fetus during an abortion. Those samples were sent to the Minnesota Bureau of Criminal Apprehension (BCA) to file as potential use as evidence.

In July 2009, the BCA notified police of a possible DNA connection between the fetal evidence and Barbour, who provided a DNA sample while a convict in Missouri.

Police learned in their records that Barbour had a "significant relationship" with the girl's mother in 2001 and 2002 that included his arrest on suspicion of assaulting the woman.

Police tracked down the girl last Oct. 7, who by then was 21 years old. She told police she knew the defendant as her mother's pimp and that she had been prostituted by her mother more than 200 times, leading her to using crack cocaine.

She said Barbour would bring men to her for sex at an address on Charles Avenue. She added that Barbour had sex with her at least 20 times.

Later in October, police tracked Barbour to the Kansas halfway house, where he had been living while on probation after his release from prison in September.

His criminal record includes convictions for robbery, forcible sodomy and vehicle theft.

Paul Walsh • 612-673-4482