Documentary depicts what happened in Rio de Janeiro on June 12th 2000, when bus 174 was taken by an armed young man, threatening to shoot all the passengers. Transmitted live on all Brazilian TV networks, this shocking and tragic-ending event became one of violence's most shocking portraits, and one of the scariest examples of police incompetence and abuse in recent years.

P.S:- this is the documentary about the movies, and there is another movie based on the central characters life and how things took a ugly turn for him and how he got killed for it. I have seen both the movie and the documentary and they both have critical acclaim on rotten tomatoes eh? if you like something different which might hurt you up and make you uncomfortable, give this a shot, the documentary is being shot by Jose Padilha who happens to be the director of 2 of my favorite brazilian movies called Elite Squad 1 and 2, and he has also the producer of Narco series, which is based on the kingpin Pablo Escobar

Gets a solid 7.8/10 from me for both the movie and documentary.
But please check the movie first if you can, you would get a more better perspective about the central character.