It's not just that you need a system that adequately prosecutes and punishes crime in order to keep vigilantes in check. Most such systems evolved as an explic

It's not just that you need a system that adequately prosecutes and punishes crime in order to keep vigilantes in check. Most such systems evolved as an explicit alternative to systems based on vendettas or lynching. These latter modes of prosecution and punishment are always lurking under the surface because they were there first and could only be inhibited by more civilized modes; they were never abolished by them.