A boater found the first newborn in 1999 near a Red Wing marina. The second, a boy, was discovered in 2003 near Frontenac.
Goodhue County Sheriff Dean Albers says a dock worker found the third newborn in March near the Treasure Island casino and resort marina . Her body was badly decomposed from months in the water.
Albers says DNA testing has revealed that the first two infants are likely Caucasian and had the same mother. Those two children were born alive, and placed in the river shortly after birth. Albers says they were likely still breathing.
"We have two different mothers whose children were left in the river. We suspect the people who left the children in the river knew the area. We also suspect the mothers concealed their pregnancy, but were likely to act strangely particularly around the time the newborns were left in the river," he said.
Albers says testing on the third infant shows she was almost certainly Native American and unrelated to the first two infants. But Albers says the child had been submerged too long for investigators to determine whether she was born alive or how she died.
The Prairie Island Indian Community is located just north of Red Wing. It owns the Treasure Island Casino. The tribe released a statement saying it is cooperating fully with investigators, but it does not believe any of the babies came from the tribe.
Police have created a profile of a woman who might have done this. They believes she is single, between the ages of 17 and 24, and probably concealed her pregnancy.
Albers says he believes these deaths are murders and were likely committed by the infants' mothers. His department has DNA tested dozens of women and followed over 50 leads. But even with that, police were at a standstill in the case.
Bureau of Criminal Apprehension Superintendent Tim McNalley says that prompted his department and the Goodhue County sheriff's office to look for racial markers. Authorities knew from earlier DNA testing that the first two children were related, but state labs don't have the capabilities to determine race. The DNA was sent to a privately owned Florida lab.
"The analysis that we have now from the Florida lab will help us narrow the focus on the pool of people who are likely the mothers," McNalley said.
McNalley says that doesn't mean the BCA can run a check of DNA matches for people in the criminal system or living in Goodhue County. He says it's hard to match the DNA of an offspring to a parent in broad circumstances like these. Instead, he says he's hoping this will prompt more information from the public.
"Three pregnancies, three births, three deaths; somebody noticed something. Those things don't happen without somebody having some information," he said.
Sheriff Albers says it's unclear whether anyone assisted the mothers in these crimes, but he believes both women knew the Red Wing area. And he's concerned this will happen again.
"It's now been shown that one person can do this twice," he said. "And that really concerns me. Was the third one a copycat? Or the idea was from the first two? Maybe the third one decided that was what they were going to do, and I don't want a fourth. We need the public's help."