BLOOD-MONEY, colloquially, the reward for betraying a criminal to justice. More strictly it is used of the money-penalty paid in old days by a murderer to the kinsfolk of his victim. These fines completely protected the offender from the vengeance of the injured family. The system was common among the Scandinavian and Teutonic races previous to the introduction of Christianity, and a scale of payments, graduated according to the heinousness of the crime, was fixed by laws, which further settled who could exact the blood-money, and who were entitled to share it. Homicide was not the only crime thus expiable: blood-money could be exacted for all crimes of violence. Some acts, such as killing any one in a church or while asleep, or within the precincts of the royal palace, were "bot-less"; and the death penalty was inflicted. Such a criminal was outlawed, and his enemies could kill him wherever they found him.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)