It has been three years and seven months since Dec. 14, 2012, when a troubled 20-year-old man shot his way into Sandy Hook Elementary School in Newtown, Conn., then shot his way through hallways and classrooms killing 20 first graders and six school employees.

The grief still sears the families who lost children, still plays cruel tricks of the mind.

Producer and director of the film and families of the children will be at the Martha's Vineyard Film Festival screening.

“Sometimes traveling is easy for me,” said Nicole Hockley, in a new film about the aftermath of Sandy Hook. She lost her son Dylan. “It’s like then I can imagine he’s home. So when I come home from traveling, it’s just . . . it’s having to accept it all over again. And I don’t know how you’re supposed to get over something like this.”

Newtown, a heart-wrenching documentary featuring three families who lost children in the mass shooting, their journey through grief, and the resilience of the community which gathered around them, will screen at the Chilmark Community Center on July 20 at 8 p.m.

The producer, Vineyard Haven summer resident Maria Cuomo Cole, will talk about the film following the screening. The director, Kim Snyder, and several members of the families which appear in the film are also scheduled to travel to Martha’s Vineyard for the discussion arranged by the Martha’s Vineyard Film Festival.

“This story, I felt, had to be told,” said Ms. Cuomo Cole, in an interview with the Gazette this week. “It cannot be forgotten, certainly. I think it has been a tipping point for the country, in really thinking about their own communities and their own family safety. This really hit home. This can happen anywhere. If it can happen in Newtown, a beautiful American, safe, seemingly safe community, then it can happen to any American anywhere in the country. It gave us an opportunity to follow the trajectory of gun violence, what really happens to a community when the cameras are gone. The country is focused on episodes of gun violence, through news coverage and then we move on. This is an opportunity to really explore what happens to those left behind.”

Producer Maria Cuomo Cole, a seasonal Vineyard Haven resident. — Dean Kaufman

The documentary is extraordinarily difficult to watch at times, with video of the victims trick-or-treating, delivering Christmas goodies to neighbors, or participating in school pageants, juxtaposed between their parents in the depths grief, after the tragedy.

“Things either happened before 12/14 or after 12/14,” Ms. Hockley says in the film. “It’s a very different life now.”

Making the documentary required a delicate and difficult balancing act, Ms. Cuomo Cole said.

“We felt strongly that the film had to be told in the authentic voices of the community,” she said. “It wasn’t our story to tell, it was their story to tell. It was an extremely difficult edit. It was difficult to balance the story, where you were providing enough information about the incident, enough background information, without retraumatization, and without exploitation.

While it does not delve into the awful details of the mass shooting, it exposes the raw horror of it in interviews with an emergency medical technician who treated one of the victims, and a Connecticut state police officer who was among the first on the scene. They don’t describe what they saw, but the emotion in their voices, the expression on their faces, leave little doubt about the inconceivable level of carnage they experienced.

“It’s not for everybody, certainly,” Ms. Cuomo Cole said. “We have found that those who experience similar loss or tragedy from violence have felt a sense of uplift and hope, from the strong theme of community resilience.”

Crime scene video from inside the shooter’s home is nearly paralyzing, as the camera picks up live ammunition on the floor, targets riddled with bullet holes stuffed in a closet, boxes of ammunition, windows taped over with black trash bags, and finally, a semi-automatic rifle on the floor.

But the filmmakers hope the screenings will be anything but paralyzing.

Maria Cuomo Cole: "We felt strongly that the film had to be told in the authentic voices of the community."

Newtown was shown at the White House a few hours before the mass shooting at an Orlando nightclub on June 13. It premiered at the prestigious Sundance Film Festival, where it was nominated for the top documentary prize.

“We plan on bringing the film to communities across the country, where the issue is most controversial,” Ms. Cuomo Cole said. “We’re hoping it will aid the conversation, catalyze the conversation, and it will transcend failed political discourse. It’s not affecting only the families of the lost loved ones. Each of these incidents affect the broader community of our country, and eat away at the fabric of our communities.”

The film is also the story of a community which grieved along with the families, and circled around them to help. It is also the story of the bond between the families thrown together by the tragedy, and their efforts to spark legislative reform on gun ownership and mental health issues.

“I am not an activist,” said Dr. William Begg with tears streaming down his face. He was one of the emergency room doctors who treated some of the victims. “But I said to myself that day . . . I’m not . . . I’m not taking this . . . I’m not taking this one lying down.”

A number of scenes in the film document families who question the randomness of it all. Why did the shooter go this way and into that classroom? Why did one child walk out of the school to his parents, while his neighbor and best friend did not? How could such evil reside in the shooter’s beautiful home with a manicured lawn, little different than those of his victims in the affluent community, and just around the corner from one of them?

“When I look at this event I see these dominoes, each of them very specific,” said David Wheeler, who lost his son Benjamin. “They had to line up that way that morning for things to happen the way they did here. When I look at that, all I see are the spaces in between, where somebody somewhere along the way could have stopped the next domino from falling.”

For tickets and more information visit tmvff.org/newtown.