Ameena Matthews roams the streets of Chicago. In her mid-40s, she has children of her own, but her mission is to keep other people's children from killing each other and taking innocent lives.
Chicago nurtured the ambitions of Barack Obama. It is also the city of Al Capone and violent drug gangs of the 1960s and 1970s that ruled entire neighbourhoods. Even as that city's notorious housing projects have been demolished and its crime rate has declined, its African-American youth still kill each other at an alarming rate. More of those youth go to prison than to university.
"Today, the perpetrators as well as the victims are much younger - that's the profound difference," Matthews says.
She is one of The Interrupters, a group that gave its name to a documentary film about violence in Chicago, and about efforts to reduce it. Working in a programme called Ceasefire, the group intervenes in potentially violent disputes on the street to prevent the worst from happening.
The men in The Interrupters are drawn mostly from the ranks of street gangs. Almost all are ex-convicts. Many are murderers. Matthews stands apart from them as a woman and a Muslim who's never been in prison. And she has deeper roots in the city's underworld as the daughter of Jeff Fort, one of Chicago's most notorious gangsters.
In 1987, Fort, now 64, was sentenced to 80 years in prison for conspiring with the Libyan government to commit terrorist acts in the United States. He got an additional 75-year sentence in 1988 for the murder of a rival gang leader. Fort's gang was originally called the Blackstone Rangers. It was renamed El Rukn after Fort converted to Islam in prison in the 1970s.
In the documentary, which plays like a reality show and opens in the UK tomorrow, Matthews says she came to Islam because of her father, after working as a gang enforcer. When she herself was shot, she decided to change direction. Her father called her, promising revenge on the young shooter. Matthews declined. "I valued life. I wasn't so quick to pull the trigger. Looking back, that was my first meditation," she recalls.
The Interrupters is co-directed by Steve James and Alex Kotlowitz. James also made Hoop Dreams (1994), an eight-year probe into the lives of two high school basketball prodigies in Chicago. Neither made the professional ranks. Few of the talented do. Each basketball star in Hoop Dreams has had a brother gunned down. One also lost his father.
James's aim was to study violence from the perspective of those risking their own lives to defuse it, such as the charismatic Matthews, who said her turn away from violence "was about the dash", referring to the punctuation mark between her date of birth and death. "It was about what I would leave between those two numbers," she says.
On camera, she chases, cajoles, lectures and comforts teenagers, speaking in street talk. (Audiences who haven't watched enough episodes of The Wire might require subtitles). Standing on the street with a child of 10, she asks a crowd: "If this brother catch a case and do a hundred years, whose fault is it?" (translation: if this child is convicted of a crime and sentenced to a long prison term, whose fault is it?).
Matthews's sermons against revenge clash with popular stereotypes in the US of Muslims as people of violence. So do scenes of praying, celebrating birthdays and roller-skating with her children and her husband, an imam at a local mosque. Prejudice, she says, "can be about Islam; it can be about that I'm a woman; and it can be about that I'm black".
"I would assume that my effectiveness comes from my past history, that I'm the credible messenger that I am because of what I did," she notes, acknowledging that the religious impulse that drives her work may not be viewed as religious by the teenagers on the streets who are desperate for her help. The grandmother who raised her is "a diehard Lutheran", she notes. "There's good and bad everywhere."
By adopting a street-level view in The Interrupters, James's mantra was "no experts". Yet the directors made an exception in interviewing Gary Slutkin, an epidemiologist who spent a decade in Africa before founding Ceasefire in 2000. Slutkin calls violence "an infectious disease".
"The Interrupters are disease-control workers," he maintains. "The Interrupters' role, like the TB disease-control workers' role, is to do this initial interruption of transmission. Most infectious disease epidemics are not treated with antibiotics. They're treated with changing behaviour," Slutkin says in the documentary.
Matthews put that theory into street language. "We were raised to think that if somebody hit you, you hit them back, that if you're hit by somebody bigger than you, you pick up something and hit them back."
That doctrine played out chillingly on television in Chicago in September 2009. In an argument, a high school student picked up a board and hit another, who died of the injury. A video of the beating was broadcast nationally and rallied the media and politicians. It is a poignant moment in The Interrupters.
For a moment, Matthews was encouraged: "We still look out for one another. For me, it's like, there's still some hope left."
Now, though, as those same politicians say they'll be cutting Ceasefire's budget, the work of The Interrupters may need a new infusion of faith.