How could a struggle over land lead to the brutal murder of an American nun? David Brancaccio interviews award-winning filmmaker Daniel Junge on his latest film "They Killed Sister Dorothy." The documentary focuses on Sister Dorothy Stang, a Catholic nun from Dayton, Ohio, who in 2005 was killed on a muddy road in the Brazilian Amazon she worked tirelessly to save. But it's also the story of peasant farmers hoping to preserve their way of life in the face of powerful industry interests. Who will dare stand up in the battle between the haves and the have nots, and will our world's ecosystem pay the biggest price? "Peasant people... don't have a chance to share in the riches that the planet can offer because some people are taking off so much of the pleasures of this world, and there's only so much to go around," Sister Dorothy said before her death.