[2] While visiting the Nickerson Gardens neighborhood of Los Angeles on an assignment, he became acutely aware of ravages of the crack epidemic and gang-related violence on poor communities of color in the United States.

Together with Boston law enforcement, city officials, community and faith leaders, and street outreach workers, Kennedy and his colleagues developed the “call-in,” a face-to-face meeting with gang members in a forum setting, during which this partnership of city stakeholders "clearly communicates (1) a credible, moral message against violence; (2) a credible law enforcement message about the group consequences of further violence; and (3) a genuine offer of help for those who want it.

One important element of the call-in message is that it provides what Kennedy calls an "honorable exit" from violence and the street code that promotes it, "a way to step back without losing face.

The Baltimore intervention, begun in 1998, proved to be a particular challenge and highlighted some of the difficulties of implementation, especially in working with rival political officials and sustaining the strategy.

[4][5] Using the principles developed in his previous research, Kennedy began to craft an approach to eliminating overt drug markets, a problem poisoning America's most troubled communities and driving violence.

"[4] He theorized an approach to eliminating drug markets that would combine formal and informal social control, using call-ins to communicate an antidealing message from community leaders and a promise of swift, certain sanctions from law enforcement.

[4] High Point, North Carolina, a city already using Kennedy's approach to reduce violence, was the first to pilot the new strategy for eliminating its overt drug markets.

As in the Group Violence Intervention, Kennedy designed a strategy for High Point to focus on the core population driving the problem.

High Point law enforcement arrested the small number of dangerous drug dealers, those with a history of violent offenses.

The strategy has now been widely and successfully replicated throughout the U.S.[1][6] Within the Drug Market Intervention, Kennedy also developed the concept of "racial reconciliation" necessary to heal relations between law enforcement and communities of color before their collaborative work could proceed.

[4][7] The process of racial reconciliation was also the subject of a national U.S. Department of Justice working session in 2012 and has been a topic of increasing interest for communities and law enforcement agencies nationwide.

[7] Kennedy currently directs a research center at the John Jay College of Criminal Justice in New York City, a position he has held since 2005.

Through the National Network for Safe Communities, Kennedy is currently assisting numerous cities to implement the Group Violence Intervention, including Chicago, IL; Detroit, MI; Baltimore, MD; New Orleans, LA; Baton Rouge, LA; South Bend, IN; Chattanooga, TN; and three cities in the state of Connecticut.

Recognizing that the gang members were arming themselves because of the escalating violence and the fears they had for their safety, the police pledged to react strongly to any threats against those cooperating with the effort.

This new framework for deterrence, Kennedy argues, will reduce offending by enhancing both formal legal sanctions and informal social control.