Matthew Heineman's purpose behind the documentary is to show how effective these vigilante groups are and there underlining motive and the development of these groups. Are they doing good?
The Knights Templar is the main drug cartel focused in this documentary as it follows the state of Michoacán, Mexico, the foundation of the Knights Templar.
The goal of the Autodefensa is too stop the Knights Templar and eventually all drug cartels from distributing drugs and killing the Mexican people, as the Mexican government is corrupt and in fact aid the cartels.
The message throughout the film is that corruption causes other to become corrupt and as long as there is pain and suffering people will continue to commit crime; everyone eventually succumbs to crime in order to possess fortune and/or escape poverty.
The audience is the human population in order to inform the general public the true sadness and atrocities that are occurring not only across the border but in our own country.
Matthew Heineman's main objective was to show how this "line" between good and bad can shift and how through influence and corruption this line can change dramatically.
Matthew also showed a realistic and never ending conflict in the world; Drugs.