What's this movie called? Drama/Adventure?

There's a group of friends, maybe college-aged, and they go on a trip together in a jungle/sort of Latin America type place. Then they run into these hostile locals. They kill one of their friends named Demetri and then one of the villager's own kids for touching some vine or something. The main girl's name is Amy (wears gles) and she's the one with the camera.