The standard "peacemaker" in this highland Peruvian provincial capital is a whip fashioned from the twisted sinew of a bull penis. It gets a lot of respect. So do the well-organized bands of citizen vigilantes who wield it.

Their rise over the last decade is just one example of how Latin Americans are responding to corrupt, indifferent police forces and the erosion of state-run criminal justice.

For all but the most serious crimes, justice in Cajamarca, a city of 200,000, is routinely administered by these grassroots citizen patrol units known as rondas urbanas.