The Utah State Medical Examiner's Office confirmed through fingerprint and dental records that the body found Tuesday was that of Alexis Rasmussen, said North Ogden police spokesman Paul Rhoades. She was missing since Sept. 10.
"This is certainly not the outcome we were hoping for," he said in a statement. "All indications are that Alexis was a very outgoing and loving person."
He said an investigation continues into the cause of the teen's death, who might have been responsible for it and "why this tragedy occurred." Police have not named any suspects in the case nor specifically declared it a homicide.
Family members have acknowledged that Rasmussen has run away before, and police previously said they were treating the investigation as a missing person case.
In a statement on its Facebook page, Rasmussen's family asked for privacy during the grieving process, the Standard-Examiner in Ogden reported.
A tip from a confidential informant led police to the grave site in Morgan County, a rural county north of Salt Lake City. The tip was directly related to the investigation into the girl's disappearance.
Police said the North Ogden girl was last seen when she was babysitting on Sept. 10, but she reportedly left before midnight to meet a friend.
Rhoades said officers have talked to that boy, but he said he only texted Rasmussen that night and didn't meet her.
The couple she was babysitting for have since been arrested, and the mother has been charged with two felonies for fraudulent prescriptions. Authorities have said the charges are unrelated to the disappearance of Rasmussen.