It's not so long ago

Before Meiji era, unless Edo era, there was a legal system called "Adauchi" in Japan.
Written like 仇討ち, read like Adauchi.

It's an overt system to accomplish a vengeance and only someone's family can do that.
When someone was killed by someone else, his family could make a submission to authorities and when they could get a permission, the bereaved family could kill the assailant legally.

So the assailant, who knew that the permission was granted, was going to run, hide, so not to be found.
The family follows, over and over and when they find him, they show out the permission paper, introduce themselves to tell the assailant who they are, and why they need to do adauchi, and then try to kill him.
That's the strict manner for it, should not just assault him and kill him.
The bereaved family was allowed to attack the assailant all by themselves, like multiple members of the family, and the assailant was allowed to fight back, by his own, but no one should help any side of people when the showdown happens.
Sometimes the family failed, sometimes succeeded.

It's not so long ago, only 140 years ago still there was such system.