Brazil is the leading economic power in South America, yet it still has serious crime as well as a large disparity between rich and poor.  Many poor Brazilians live in shanty towns -- called favelas -- that surround the cities. Favelas - characterized by poorly constructed buildings and inadequate infrastructure - are often the center of criminal activity. These shanty neighborhoods date from the 1920s, but their populations are still growing.  Brazilian authorities have made tackling crime and poverty in the favelas a priority.  

Steve Mort has the story from Sao Paulo.