Now there are three more, after a box with the remains of three children was found in a Missoula shed.
"The thing is, there are missing children all over the world", Missoula Police Searteant Travis Welsh told reporters. Forensic testing revealed they likely belonged to children between the ages of 2 and 4, 5 and 8, and 6 and 10.
No suspect has been now identified in the case, but neighbors of the home where the remains were found are concerned about the tenants.
Missoula Police spokesman Sgt. Travis Welsh said on Friday morning that they are continuing to get inquiries from across the US inquiring about the bones.
Missoula Police tell MTN News they will be conducting interviews with people of interest in the next few days surrounding the case of bones found in a Missoula shed.
"Bringing closure to them is a huge thing for us and we want to be able to do that for them and the community", Brewer said.
Tanner, Alexander and Andrew Skelton were 5, 7 and 9 when they disappeared in Morenci on Black Friday that year. The boys' mother, Tanya Zuvers, had exclusive custody of the children, but she allowed them to visit their father for the holiday.
On Thursday night, Tanya Zuvers, the missing MI boys' mother, posted about the news out of Montana on Facebook.
Montana reports that Michigan State Police contacted authorities in Missoula, Montana regarding a case of children's remains that were located. When Skelton did not return the children the next day, Zuvers called the police.
In the years since, the boys' disappearance has been vigorously investigated by the Morenci Police Department, FBI and Michigan State Police (MSP).
When pressed by authorities about what he had done with his sons, Skelton originally said they were with a friend, Crime Watch Daily reported.
Skelton was charged with three counts each of unlawful imprisonment and parental kidnapping. He is now serving time in prison for unlawful imprisonment.
Now police are piecing together the identity of the boys and where they may have come from.
Back in Montana, police this week have repeatedly searched the property where the bones were discovered, with the assistance of an anthropology professor and graduate students from the University of Montana, according to court filings.