'Avenger' in the Bible

otherwise the avenger of blood might pursue the offender in the heat of anger, and overtake him, because it is a long way, and take his life, even though he did not deserve to die, since he did not hate his neighbor beforehand.

then the elders of his own city shall send for him and have him taken back from there and turn him over to the avenger of blood, so that he may be put to death.