Eastern State Penitentiary, Pennsylvania, USA Apparition

This video was taken by TAPS (The Atlantic Paranormal Society) at Eastern State Penitentiary, Pennsylvania, USA, and was featured in their series Ghost Hunters.

When they staked out a prison, they caught on tape what appears to be an apparition. It seems to materialize out of thin air, with its back to the camera, and then it ran down the hall. It plays 3 times at different speeds and definitions. The team tried re-enacting this and inspected the area thoroughly, but were at a loss to debunk this.