An anthropologist made a surprising discovery in a Florida thrift shop’s Halloween section on Saturday, officials said.

The North Fort Myers shopper spotted a skull and recognized it as a human skull, according to the Lee County Sheriff’s Office. Responding detectives also determined the skull belonged to a human.

The store owner said the skull had been in a storage unit that was purchased years ago, authorities said.

The Lee County Sheriff’s Office is working with the local medical examiner to run further tests on the skull. Officials do not believe the case is suspicious in nature.