Nearly 1.7 million American children live in homes with unlocked and loaded guns. Thirteen-year-old Eddie Zee Holmes found himself in one of those homes after school one day in February 2014.

Eddie, a seventh grader in Puyallup, Washington, went to a friend's home, along with three other classmates. There, they had a snack and played with the dogs, before one of the boys disappeared into a bedroom and returned with a Mossberg shotgun.

The other boys, all young teenagers, were curious. The shotgun was new, purchased by a parent a few days earlier. And then, suddenly, the gun went off.

"It felt like the whole ground was shaking," one of the boys later told police.

Eddie, who was still playing with the dogs, was shot in the chest. One of the boys called 911 while another started CPR. But Eddie was pronounced dead later that afternoon.

Eddie's story is one of many featured in Making a Killing: Guns, Greed and the NRA. When I began this documentary, I knew it would be difficult, and it was; I spent 18 months confronting death and tragedy. As a father of four, I know my experience pales in comparison to the unbearable pain Eddie's mother, Sandy, lives with every day. But, through her grief, Sandy offers inspiration for all of us through her hope and strength.

For months, Sandy regularly attended local gun shows along with her sister, Eva, and niece, Sandra. They carried signs with Eddie's photo and messages imploring gun show attendees to lock up their guns.

"If they had only locked it up," she told me, "my son would be here today."

Such a simple thing, but one that could save hundreds of children's lives. In fact, 70 percent of unintentional shooting deaths could have been prevented if the gun had been stored safely. Despite child safety laws on the books nationwide for things like car seats, bicycle helmets, and life jackets, many states have no regulations to keep children from accessing guns at home.

In February 2013, a year before Eddie was killed, the NRA lobbied against one such law that would have required Washington State residents to store their guns safely. If the bill had passed, Eddie might still be alive.

The NRA preaches that teaching gun safety to children is the answer. Wayne LaPierre, the group's CEO and Executive Vice President, even boasted that the NRA's child accident prevention programs are "second to none." But, if that's true, why are seven children shot and killed every day in the United States?

The truth is that the NRA has a vested interest in keeping guns as unregulated as possible. Less regulation means more guns sold, which ultimately leads to more money in their pockets. Gun companies have given at least $20 million to the NRA, and the top executives make millions each year. Mr. LaPierre himself made nearly $1 million last year alone.

It's a similar theme I've discovered again and again while researching this film: NRA and gun company executives put profits ahead of safety. The result is families torn apart by senseless violence. For Sandy, it means life without Eddie, a boy who loved skateboarding and his dog Buddy, and who idolized his older brother Jose. Sandy continues to go to gun shows and to share her story in the hope that it will convince someone to store their gun in a lock box or safe, where children won't be able to access it.

Sandy isn't the only one trying to stop this crisis. Ryan Hyde, an entrepreneur in Salt Lake City and father of eight, created a biometric gun safe that will only open for an authorized user. Others, like Kai Kloepfer, an 18-year-old from Boulder, Colorado, are working on smart guns, which won't fire for anyone other than their owner.

And, for those of us who can't invent a new, safer gun, there are other ways to fight back. Over the next few months, volunteers around the country will be hosting 1,000 free screenings of Making A Killing, and you can sign up to host a screening, too.

This is a film that will give people the tools to fight against the harmful directives of the NRA. It is my hope that we can continue to carry Sandy's message and protect other families from the tragedy hers has faced. Most of all, I hope that together, we can stop the gun lobby and those who stand to profit from violence.