Results from tests performed on saliva from the mother of Rilya Wilson showed that a match with Precious Doe was "scientifically impossible," said Capt. Cy Ritter.
DNA from the mother arrived in Kansas City on Monday, and tests were complete late Thursday, Ritter said.
Police had said the lab would have results quickly if tests appeared to eliminate Rilya's mother as that of the girl nicknamed "Precious Doe," whose headless body was found in Kansas City in April 2001.
Florida's Department of Children and Families lost track of Rilya last January, when the girl's caretakers say she was removed from their home by a woman who claimed to be a DCF worker. The caretakers say the girl was never returned. DCF skipped required monthly visits and reported her missing April 25.
Police are now looking more closely at the woman who was caring for Rilya. Geralyn Graham, the caretaker who claims she handed over the foster child to someone who identified herself as a state child welfare worker in January 2001, suffered from dementia and needed her sister to serve as her legal guardian, according to court records.
Geralyn Graham was suffering from the mental disease and needed a legal guardian because of a May 1996 car accident, Pamela Graham, the sister, wrote in response to a lawsuit in October 2001.
The state Department of Children & Families, which had taken custody of Rilya when she was 5 weeks old because her mother was homeless and addicted to cocaine, lost track of the girl and reported the girl missing April 25. A caseworker had failed to make monthly visits to check on Rilya.
Last week, Kansas City police compared a palm print of Precious Doe to one provided by Rilya's caretakers. The prints didn't match and police said they would look to DNA tests to definitively rule out a match.
The mystery surrounding Precious Doe has transfixed Kansas City during the year since her body was found in a wooded area in the southern part of the city. Police and the public were vexed that no parents or other relatives of the girl had come forward to claim her.
A shrine stands along a path into the wooded area where she was found, and posters showing a police composite drawing of the little girl were taped and stapled all over the city. Her body was buried here in December.
At the end of April, police had received 811 leads, including calls and letters from around the country. All had turned up nothing.
In the weeks after Precious Doe was found, police combed missing-persons reports and contacted day-care centers and schools. The FBI took blood samples from family members of 27 missing black girls in the same age range from around the country. And the case has been featured several times on television's "America's Most Wanted."
Police thought they had a match when they received several tips that the computer-generated image of Precious Doe resembled a girl missing from Tacoma, Wash. But DNA ruled out that connection, as well.
Police said Friday there was no relief in the news that the girls are not the same.
"We worked long and hard on this case, and we will remain diligent in our efforts to resolve the case," Ritter said. "There's no relief at all. We are just determined to find out who this person is."