Grace Packer's dismembered remains were found by two hunters on Oct. 31 along an isolated road in Bear Creek Township, Luzerne County.
Her mother, Sara Packer, has been arrested and charged with obstruction and endangerment, and has been named a person of interest in Grace's death.
Sara Packer reported her adopted daughter missing on July 11 from her home in Abington Township.
Sara said she had sent Grace to her room following an argument over the teen's request to go to a friend's house.
She told police she discovered that Grace was gone the next morning, and that she had taken $300 from their home.
Police say they requested a recent photo of Grace from her mother so they could investigate. Sara allegedly told police she would drop a photo off at the station, but never did.
Authorities say after numerous unsuccessful attempts to contact Sara Packer through August, on Sept. 7 investigators learned Grace and her younger brother had been withdrawn from Abington School District.
The investigation later revealed Sara had moved to Quakertown without alerting police, and her 12-year-old adopted son had been enrolled in Quakertown School District. However, there was no indication that Grace had been enrolled or that there were plans to enroll her in the district.
"When somebody goes missing, we expect people are going to work with us to try to identify that person, try to identify where she is. That didn't happen," said Montgomery County District Attorney Kevin Steele.
Police also learned Sara Packer had been receiving $712 monthly for care and custody of Grace, and that on Aug. 22, Sara completed a Continuing Disability Review Report related to Grace, never disclosing the girl's disappearance.
Records show between July 1, 2016, and Nov. 10, 2016, while her daughter was reported missing, Sara Packer spent more than $3,600 of disability funding intended for Grace.
Authorities are now hoping the public can help with information about the mother and daughter in the days before the teen disappeared.
"That's why we put the photos out there. Maybe somebody has recognized them - maybe somebody from the schools, somebody from the community that they've been in," Steele said. "You've heard about how this was in Abington and Quakertown - these are two essential areas that we're looking at, and if anybody has information in regard to seeing them together, a last point in time, anything that's going on is going to helpful to this investigation."
Sara Packer remains in custody after failing to post $10,000 bail.
An autopsy determined Grace's death to be a homicide. The cause of death is not being released at this time because of the ongoing investigation.