The new Bolivian constitution passed by the socialist government of Evo Morales included new legal status for "communal justice" of indigenous groups throughout the country. Since the new law took effect at the beginning of the year there have been a number of "lynchings" in the country, including the murder of four policemen a few days ago by indigenous leaders in the Potosi area. The killers have declared a so-called "red zone" where government agents are no longer welcome. Evo will have his hands full dealing with this mess for years to come. There is something to be said for the "rule of law." See Spanish coverage at this link and this one.
For a historical look, in English, by the Cochabamba-based Democracy Center at the issue take a look at this blog post.