It’s actually fairly explicit in the Torah, specifically in Numbers chapter 35. The Mosaic code there established cities of refuge to which killers were to be allowed to travel and be judged, where they would be free of revenge from those wronged until the priests decided whether their offense was murder, manslaughter, negligence, or accident, and imposed the appropriate penalty.
It’s actually fairly explicit in the Torah, specifically in Numbers chapter 35. The Mosaic code there established cities of refuge to which killers were to be allowed to travel and be judged, where they would be free of revenge from those wronged until the priests decided whether their offense was murder, manslaughter, negligence, or accident, and imposed the appropriate penalty.