Murdrum
Murdrum was the crime of murdering someone in a secret manner in medieval English law.
Origins
It was introduced into Anglo-Saxon law by the Danes. It is distinguished from simple homicide. In the laws of Cnut an unknown man who was killed was presumed to be a Dane, and the vill or tithing was compelled to pay 40 marks for his death.After the Norman Conquest of 1066, the law was revived to protect the Anglo-Normans. The origins of the Norman law are described in the 12th-century Dialogus de Scaccario:
In later years, the Anglo-Normans became indistinguishable from the native English. Nevertheless, the murdrum was retained as the most effective law against secret murder no matter the victim's ethnicity.