From Tatters of the King
According to Nurse Price Yates was slashed with at least 2 knives, and there was more blood in the cell than could have come from a single man, but no sign of a second victim.
Harriwell claims 'the Devil' killed Yates.
The Herefordshire police assume Harriwell was the killer, and closed the case since Harriwell was already incarcerated. The staff of the Asylum disagree with this conclusion.