Violence has been existing since time immemorial. People in the times of the Old Testament were not free of it. Before there were judicial or police authorities the people of Israel were endeavouring to break the spiralling cycle of violence and counter violence which existed. Beside stoning as a punishment for certain dangerous criminals,  bloody vendetta was also an act of punishment. As blood was considered to be the source of  the well of life, it was under the protection of God. Bloody vendetta was a duty for the clan
(Num. 35,19).The next male relative had to kill the murderer or, instead of him, another member of his clan.
The only advantage of bloody vendetta was that it was the only protection against attacks of other clans. Because everybody  knew that with such an attack  they made enemies of all the members of these clans,  they could also expect  their revenge. Bloody vendetta protected the lives of  people, too, they were under the protection of God.On the other hand there were serious disadvantages. There was the possibility of chain reactions of revenge and counter revenge. Revenge was possible not only against the criminal but against each member of the clan, too (Gen. 34,1-31). In extreme cases whole clans were killed. Examples of efforts to avert these fatal consequences are Cain’s marking by God (Gen. 4,15) and King David’s speech against bloody vendetta (2.Sam. 14,5-11). Even then there was a difference between murder and manslaughter (Ex. 21,13) and there were towns of sanctuary or asylum for persons who had killed unintentionally (Dtn. 4,41-43).