Who is the culprit of Nancy Drew The Ghost of Thornton Hall?

In "Nancy Drew: The Ghost of Thornton Hall," the culprit is revealed to be Charlotte Thornton, who faked her own death to escape her family's dark history and the pressures of her life. She orchestrated the ghostly occurrences to keep others away from the estate. The game involves uncovering the truth behind the Thornton family's secrets and the mystery surrounding Charlotte's disappearance.