For more than three decades, the disappearance of 12-year-old Jonelle Matthews has puzzled the Greeley Police Department. However, it's now been determined that the human remains discovered at an oil and gas site on Tuesday, July 23, belong to the missing Greeley girl.

Jonelle Matthews was last seen around 8 p.m. on December 20, 1984, after being dropped off at her home at 320 43rd Ave. Court by a friend and friend's father, following a choir concert.

The bones were uncovered by oilfield workers at Weld County Road 49, on privately-owned land, located about 10 miles southeast of LaSalle. The Weld County Coroner's Office was on scene Wednesday afternoon.

According to investigators, the tattered clothing that was found with the bones matches what Matthews was wearing the last night she was last seen.

Law enforcement is still working to chase down leads regarding a suspect in this case.