From the Economist's 'The World in 2009', Crime Interrupted by Joel Budd

The approach that will come to prominence in 2009 is almost the exact opposite of zero tolerance. Rather than cracking down on petty offenders such as turnstile-jumpers and squeegee men, the authorities will focus on those who are most likely to kill or be killed. Some may be drug dealers recently released from prison. Others may be the associates of people recently wounded by gunfire. What makes the approach particularly novel is that it depends on local people. Rather than insisting on zero tolerance from the police, it tries to change what the residents of crime-infested areas will tolerate.
The new method has been quietly honed for almost a decade in Chicago, where it is known as Operation Ceasefire. It has two main tools. The more conventional one is a team of outreach workers who try to mobilise communities to oppose violence, often in partnership with local clergy. Then, at night, “violence interrupters” hit the streets to sniff out trouble. Often former gang members and graduates of the prison system, the interrupters have a hard-nosed approach to law and order. They may, for example, encourage an aggrieved man to consider beating someone instead of shooting him, or try to convince rival drug-dealers that a turf war would be bad for business, as it would attract the police.