Like many in the US, filmmaker Craig Atkinson was glued to the news coverage of the Boston Marathon bombing in 2013. But Atkinson was unsettled by what he saw during the manhunt for the bombers.

"I was shocked by the way that the police were approaching the community," Atkinson told Business Insider, recalling SWAT teams searching homes without warrants. "It was like fear had got the best of us."

Atkinson's father was a police officer in Oak Park, Michigan, a northern suburb of Detroit, for 29 years and became a member of its SWAT team when it was formed in 1989. His memories as a child are filled with playing the hostage as his dad's SWAT team conducted training drills and, when he got to his teens, playing an armed assailant.

With a unique eye to the evolution of SWAT over his life, Atkinson saw in the Boston Marathon bombing a disturbing reality in the militarization of the police in the US.

"It was such a departure from the way that I felt my dad's SWAT team approached the community," he said.

So Atkinson decided to investigate it in his directorial feature debut, "Do Not Resist."

Atkinson teamed with producer Laura Hartrick to make a gripping documentary (which won the best documentary grand jury award at this year's Tribeca Film Festival) that examines how police departments across the US are using government grants to beef up with military equipment to fight terrorism. But for small towns that do not face the same kind of threats as Boston or New York, the equipment is used mostly by SWAT teams to serve search warrants and assist in crowd control.

An MRAP in "Do Not Resist." Vanish Films Starting in 2013, Atkinson traveled the country to investigate the militarization phenomenon. He visited a SWAT competition in Florida; got a ride-along on a new MRAP, a vehicle designed to withstand IEDs, that the police department of Wisconsin's Juneau County (murders in 2014, zero) just received; and sat in on a city-council meeting in Concord, New Hampshire, (murders since 2004: two) for the approval of a BearCat, or ballistic engineered armored response counter attack truck, for its police department.

But the movie changed when 18-year-old Michael Brown was fatally shot by the police in Ferguson, Missouri, in August 2014.

"Before Ferguson, we had 80 hours of footage to educate people," Atkinson said. "That was no longer needed because the Ferguson story showed it."

Atkinson and Hartrick raced to Ferguson and captured incredible footage of the protests that occurred there following Brown's death (Atkinson is best known for his cinematography work on films by Heidi Ewing and Rachel Grady like "Detropia" and "Norman Lear: Just Another Version of You," for which he had an additional cinematographer/camera operator credit). With officers seen in riot gear, some shooting tear gas from atop BearCats, Atkinson believes the movie paints a clearer picture of the Ferguson police department's actions than cable-news coverage did at the time.

"Most news outlets there had to go file stories at 10 or 11 o'clock at night," Atkinson said. "But we had the luxury to just wait it out until the end, and there were a lot of exchanges between the police and the community in those hours when no one was looking that changes the entire dynamic of what was being reported."

Ferguson footage from "Do Not Resist." Vanish Films Atkinson shows SWAT teams following crowds back into their neighborhoods and deploying tear gas after the city-imposed curfew. Officers can be seen facing off with citizens who are standing on their own front lawns.

But with his general knowledge of SWAT procedure, Atkinson also noticed what seemed like a lack of training by the Ferguson police.

"They would shoot the tear gas towards the crowds but also on the sides of them, so they had nowhere to go but towards the police," Atkinson said.

In the haze of tear gas, Atkinson captured on film one female protester saying to anyone who would listen: "They need to stop giving these boys these toys because they don't know how to handle them."



"Do Not Resist" also explores the future of policing, featuring conversations with people behind aerial surveillance and face recognition, both of which are being used in some US police departments. Then there's the work of Richard Berk, a professor who is developing an algorithm that seems taken out of "Minority Report," as it predicts at a person's birth whether the person will become a criminal.

But the section of the movie that is likely to remain with most viewers long after watching are the words of the top trainer of military law enforcement in the country, Dave Grossman.

Atkinson was allowed to film Grossman's class, which was full of SWAT commanders from across the country, and what is revealed is a chilling presentation in which Grossman tells the men such things as "we are at war and you're the frontline troops in this war" and "the best sex you've had in your life" is when you come back home alive from the job.

Craig Atkinson. Tiffany Frances "I just wanted to show the American people who their officers are being trained by," Atkinson said, "and I want Dave Grossman to have to explain himself to why this is the most effective way to police our streets in this era. I think we have outgrown that philosophy and we need to evolve it to accommodate what our society is actually asking us. Let's go back to a protect-and-serve model."

Business Insider contacted Grossman, and though he said he had not seen the movie, he had seen the trailer, which he is in, and thought it to be "horrendously irresponsible."

"It's got a quote of me saying, 'We are at war and you're the frontline troops in this war,' but in the context of Ferguson. That was the context they created," Grossman said. "I was talking about this land and 9/11 attacks and what's coming down the road as far as terrorist attacks. In time of war, law enforcement is essentially troops on American soil. I think that there's 9/11-scale attacks coming. What they may do is attack schools, day cares, and school buses, and what I was telling my cops is when that happens there is no elite delta force that's going to show up to save your kids — you're it."

When asked whether he was worried that his teachings might get misconstrued and that SWAT members might bring his thinking to situations like that in Ferguson in 2014 or in Charlotte this month instead of a terrorist act, Grossman said: "I don't teach tactical — I teach the mental side of the game."

Dave Grossman. YouTube/Vanish Films Grossman also dislikes the term "militarization of police." He describes things like MRAPs and BearCats as "tools" that the police "are using to stay alive."

"My presentation is always evolving, always talking about the latest science, the latest physiology, the latest case studies," Grossman said. "It is truly the most successful military law-enforcement training. Are all of these police chiefs that come to my training, are they all insane? These [filmmakers] set out to do something horrendously irresponsible. It's part of the whole war-on-cops left-wing mantra, and it is enormously harmful to business."

In a response to the above remarks by Grossman, Atkinson sent an email saying: "The righteous violence that Dave Grossman instructs officers to deploy may be effective when fighting ISIS, but while the police are preparing for the next 9/11 attack, they are engaged in 63 million police-citizen interactions a year. It is irresponsible to think that you can teach the 'mental side of the game' while not considering the broad application in which this mentality is deployed. I think it's important to note that Jeronimo Yanez, the officer who reflexively shot and killed Philando Castile as he reached for his wallet during a routine traffic stop, had previously undergone Grossman's Bulletproof Warrior training."

Atkinson also noted that Sheriff Laurie Smith of California's Santa Clara County canceled a Grossman training session out of concern that the class made officers more likely to use deadly force when it's not necessary.

"Do Not Resist" opens at the New York theater Film Forum on Friday and will be available for streaming later in the year. Here is the complete list of screening locations.