Cartel Land was nominated for an Oscar this week — putting a spotlight on the documentary that follows vigilante groups north and south of the US-Mexico border as they fight against Mexico's powerful drug cartels.

“I was really fascinated by how all this drug cartel violence was affecting everyday people and then the response of everyday people rising up to fight back,” says filmmaker Matthew Heineman about what drew him to this story of Mexico's ordeal.

“Almost every step along the way, especially on the Mexican side of the story, where I was embedded with the Autodefensas, a group of civilians who are fighting back against the Knights Templar cartel in the Mexican state of Michoacán. Almost at every stage, I was asking myself ‘what would I do if my sister was raped by the cartel, of if my brother was found hanging from a bridge?’ You know, would I take up arms? Is that right? Is that just? Is vigilantism sustainable? These are questions that plagued me, that drove me to keep going down there and try to get some answers.”

Cartel Land filmmaker Matthew Heineman

Cartel Land

On location in Mexico, Heineman did find himself in some toxic situations.

“I’m not a war reporter, I've never ever been in a situation like this before but the film led me to some pretty dicey situations, shootouts between the vigilantes and the cartel, meth labs in the dark desert night, places of torture, places I never could've ever imagined being in," Heineman says.

"When I started the film, I thought I was telling a very simple story, almost a classic western, good guys vs. bad guys, and over time the lines between good and evil became ever more blurry, and unfortunately, you know without giving away the film, what we see happen is that those who were fighting against evil, start to become evil. We see human nature taking over, and the film was a wild adventure in which I ended up with a story that I never could've dreamed of.”

As a documentary maker, Heineman spent nine months shooting. He invested a lot of time and energy and love in his film. The Oscar nomination is bringing new audiences to the film, but perhaps not as much attention as has been focused on the Sean Penn interview with the crazed drug cartel leader El Chapo. The point’s not been lost on Heineman.

“I think the sad thing, the thing that bums me out, is that it's gotten so much coverage, the arrest of Chapo, his subsequent escape through an air-conditioned tunnel, a Hollywood actor going to visit him in on a mountaintop, the amount of media attention I think is a travesty.”

Heineman says the real story is the suffering of Mexican people. “The fact that 100,000 people have been killed since 2007, 25,000+ people have disappeared, the failure of a corrupt government to protect people, American voracious appetite for drugs which is fueling this war."

He says these are the issues that we should be discussing. As for Penn’s investigative report, Heineman says “the only thing that I think was really important, Chapo said himself, ‘If I get arrested, if I die, none of this is going to change.’ Unfortunately that cycle of violence, that cycle of drugs flowing northward, I don't see it stopping anytime soon, and we see it quite vividly in Cartel Land," Heineman says. "That's why I think that the sexy story that's catching headlines is not addressing the underlying deep issues at hand here. I wish those would be discussed more in the hope that one day, perhaps, this cycle of violence will stop.”

Cartel Land is now in theaters across the country.

From PRI's The World ©2015 Public Radio International