In 1991 a group of former felons living in the District of Columbia formed the Alliance of Concerned Men. Since that time, the alliance—whose goal is to end the cycle of violence and hopelessness among troubled youth in the nation’s capital—has garnered praise and media attention, most notably after a gang truce it helped establish in 1997.

In January 1997, twelve-year-old Darryl Hall was beaten, abducted from the Simple City housing project in Washington, D.C., and then shot by three teenagers who were reportedly members of the Circle gang. The alliance, in an effort to prevent retribution murders—Hall was allegedly associated with the Circle gang’s rival, the Avenues— brought the gangs together. Two weeks after Hall’s murder, a truce was declared. Since that time, Simple City has seen...