07/17/2013 04:46 pm ET Updated Sep 16, 2013

Who Needs This Movie?

Of the 10 new documentaries to debut on HBO this summer, The Cheshire Murders is one about reality of the horrific kind.

No one is acting. The tragedy is real. You can be sure that those in it never wanted to be there in the first place. Most would say that there was no need to keep the horror going. However, as with many other real-life dramas, this is a film that was going to be made, regardless.

There will be others. You can bet that it won't be long before there is a documentary in the works to explore the Boston Marathon bombings or the massacre of school children and teachers in Newtown, Conn.

This film on "The Cheshire Murders," to be shown for the first time on July 22, is from the Emmy Award-winning team of Kate Davis and David Heilbroner, who take a close look at the 2007 murders of three members of the Petit family in Cheshire, Conn. Dr. William Petit survived the bludgeoning. His wife, Jennifer Hawke Petit, and their two daughters met a terrible death at the hands of two criminals. The filmmakers devoted years to the research and filming and they approached every aspect with intellect and care. They weave factual details of the crime with tragedy and deep sorrow. With the camera, they look straight into the faces of good and evil.

At first, I, too, didn't want the movie. One of the convicted murderers, Joshua, is my estranged nephew.

My view on this monstrous crime that was so devastating to the Petit and Hawke families and their many friends is simple and clear. The criminals bear full responsibility for their actions. There are no excuses. My action was not to circle the wagons, as some might do with the goal of protecting a relative, but rather to reach out to the victims by letter early on, apologize in person and be there in support.

So, here we are today. The documentary is being released. The tragedy is still raw and so many are still grieving, six years later. The memories poignant.

We now have to ask, Why make these kinds of films in the first place?

Documentary film history goes back to the turn of the last century. "Cinema verite," some call it. The technique is to film people when they are real and unvarnished. But it is far from a simple technique. It is not just going out with a handheld camera and putting images together. Like any form of communication -- written, filmed, spoken, composed, photographed -- the challenge is to use the medium to raise issues, ask questions, and probe as deeply as possible.

When done well, it compels people to think. And this HBO documentary does that very well. By giving voice to others on film, Davis and Heilbroner raise questions that the viewers are left to answer. The film looks at the best and worst of people and probes the police department, the correction system, and the death penalty.

If we liken the horror to an earthquake, at the epicenter the damage to the Petit and Hawke families was beyond belief. Davis and Heilbroner used a wider lens, though, to explore the impact of the quake on so many others who felt the tremors farther out and whose lives were changed. To do this, they learned about others' lives and gently encouraged them to share the depth of their emotions on film. In that sharing is the power of the film.

My wife, Reina, and I are in the film too. As I learned early in my life, either speak or don't expect to be heard. And don't shy away even when it is very tough.

For us personally, we gained strength from the kindness, dignity, and the compassion shown by the Petit and Hawke families toward us.

We have many examples but one stands out. Reina and I went to the trial during the sentencing phase with two goals: to apologize in person to the Petit and Hawke families on behalf of our family and to show our support by joining them in the courtroom on seats right behind the prosecutor Michael Dearington. While the first few days were awkward, it wasn't long before we talked openly. And then one day during the trial, the Hawke family -- Reverend Hawke, his wife Marybelle, and their daughter Cindy Hawke Renn, Jennifer's sister -- invited us to join them for Sunday lunch at the home of Doug and Kim Erickson, close friends with whom they were staying in Cheshire. As we sat around the table talking and the sadness of it all became too much, our host said, "tears are welcome here." Reverend Hawke then offered a prayer, asking that we all, including Joshua, find peace.

For me, the title of the film alone gives me the chills. And, because one of the murderers carries the same name as I, my children and the rest of my family will once again be faced with questions from those whose curiosity proves too much to resist.

Just maybe, though, it is important for all of us, myself included, to take a step back. In the midst of all the tears and sadness that don't go away, perhaps the film can create a moment to reflect and think about the kindness with which some people behave when they face life's toughest battles.

Indeed, perhaps a documentary like this is a way to learn.