The remains of a 12-year-old Colorado girl who vanished after a school concert in 1984 were found by construction workers this week, The Greeley Tribune reports. Sgt. Joe Tymkowych of the Greeley Police Department said the remains were identified as those of Jonelle Matthews, who was last seen Dec. 20, 1984. Her remains were found Tuesday at a rural oil and gas site where workers were digging a pipeline. Photos of the remains sent to the newspaper anonymously reportedly show a skull, tattered blue and red clothing, and a lower jaw with braces still attached. On the day of her disappearance, Matthews had braces and was wearing blue and red clothing. Before Matthews vanished, her friend and friend’s father reportedly dropped her off at her home after she performed at a Christmas choir concert. No one was arrested in the wake of her disappearance. Tymkowych told the Tribune that police were still “chasing down leads.”