In June, a fifth person was found guilty in the death of Derrion Albert, the 16-year-old Chicago honor roll student beaten to death on the street in 2009.
A graphic cellphone video captured the attack and made Albert's homicide a national story, but it was only one of hundreds investigated by Chicago police that year.
Albert's death also made headlines just as a small film crew began work on a documentary about violence interrupters, former gang members dispatched to their old Chicago neighborhoods to try to stop youth violence.
Eddie Bocanegra is one of the interventionists featured in the resulting documentary, The Interrupters. Bocanegra spent 14 years in prison for murder and now works with the Chicago violence prevention organization CeaseFire, which runs the interrupter program.
"I'll be honest," Bocanegra tells NPR's Neal Conan. "During the filming, I was very ashamed revisiting some of these places and then taking somebody with me."
While taking outsiders to the scenes of his former crimes was humbling for Bocanegra, he says it also served as a fresh reminder of the positive changes he's trying to make in his old neighborhood.
"I look at my life, where it's at now, and what I've done," he says. "I feel that I've failed more than I have succeeded, but I do take some comfort in knowing that there [are] times that I have made a difference in some people's lives."
Bocanegra says the key to CeaseFire's work is understanding how growing up in the midst of gang violence influences young people.
"If you really think about it, most of the youth that we work with suffer from [post-traumatic stress disorder], from mental disorder," he says. "So a lot of the time it's learning how to address that. It's learning how to communicate with them."
Bocanegra works primarily with young men, ranging from their teens to their 30s. He says he's able to intervene in heated situations in large part because of his own credibility in the community.
"It opens up the doors and ... other places I wouldn't be able to get into ... or the average person wouldn't be able to get into," Bocanegra says. "Because of my past, my background ... I know the signs. I can understand the body language. It makes it a lot easier to know what to say, what not to say, who to get involved with the mediation."
And while The Interrupters demonstrates CeaseFire workers' ability to help defuse violent street confrontations, it also demonstrates a difficult truth: Conflict mediation is dangerous work.
Author Alex Kotlowitz produced The Interrupters, and, with filmmaker Steve James, worked closely with Bocanegra and his CeaseFire colleagues in the making of the film.
Kotlowitz tells Conan that two violence interrupters were shot during the year the crew spent filming. One of them, he says, "was actually visiting his father and a dispute erupted on a porch nearby."
Kotlowitz says that when the interrupter tried to help resolve the dispute, it soon became clear that his presence wasn't helping.
"He did the right thing, which was to turn and leave," Kotlowitz says. "And as he was leaving, he got shot in the leg."
Kotlowitz says he and his crew also witnessed confrontations where they felt compelled to leave for their own safety, or for the safety of the interrupters.
Bocanegra says it felt weird to be followed around by a film crew while working with young gang members. People would want to know who the filmmakers were and what they were up to.
"You're ... an outsider [in] the community," Bocanegra says, "and there are certain things they don't necessarily want to expose."
"I know it's a rather grim landscape," Kotlowitz adds. "But for us, in the end we were inspired by the likes of Eddie. I hope people who watch the film will be inspired, as well."