The Werewolf of Chalons
This one dates back to 1598, when an unnamed tailor was accused of torturing, molesting and murdering children in the local area.
While his name is lost to time, his nickname still holds; the Wereworld of Chalons. When he became a suspect, authorities investigated his shop and found barrels full of bleached bones and corpses that were dressed like slaughtered calves.
He was burned at the stake, protesting his innocence to the end, and cursing the families of the victims.
You forgot Harold Shipman, probably the world's most prolific serial killer and a doctor.