GOODYEAR, Ariz. (WFLA) — A Goodwill manager made a terrifying discovery while sifting through a donation box in Goodyear, Arizona, Tuesday.

The Goodyear Police Department said the manager found what appeared to be a human skull in the box. The manager reported the finding to authorities, and the skull was given to the medical examiner’s office for investigation.

Courtesy of Goodyear Police Department

Based on the medical examiner’s initial findings, the skull was confirmed to be human. However, the police department said the remains appear to be “historic and ancient.”

Officials said they do not believe the skull is linked to a crime.