Two years ago, a Los Angeles police commander called Patrick Gannon found himself pushed to the very limit of his professional endurance.
Working in one of the city's most violent neighbourhoods, close to the epicentre of the 1992 riots, Mr Gannon was determined to push down the murder rate, most of it gang-related.
He had tried blacklisting suspected gang members through a system of city-authorised injunctions that strip young men of many of their basic civil rights. He had tried beefing up his homicide squad at the77th Street Division.
But none of that helped one particularly bloody Friday on which one shooting led to a concatenation of retaliatory attacks – 20 of them in all. So Commander Gannon tried something new, approaching civic leaders, many of them former gang members themselves, and begging them to intervene.
They did, and the result is a marked decline in killings and shootings in some of LA's most blighted neighbourhoods – particularly South LA (previously known as South Central) and Watts. The gang intervention specialists, as they are known, have worked again and again – often at considerable personal risk – to stop one incident from blowing up into a full-scale street battle.
Los Angeles is now on track to see its lowest annual murder rate since 1970 – just before the rise of the Crips, Bloods and other notorious street gangs that have since spread across the United States and seeped into the popular culture.
Gang intervention is not a new concept – civic leaders were particularly successful in negotiating a Crips-Bloods truce in the early 1990s – but what is new is the endorsement of the notoriously belligerent LA police, and the support of both the Mayor and police chief.
At the beginning of the year, both Chief William Bratton – a tough-as-nails former New York police chief – and Mayor Antonio Villaraigosa have committed themselves to a new approach. They now have 61 gang intervention specialists on the city payroll, a drop in the ocean given the magnitude of the problem, but a stark departure from previous decades of zero-tolerance suppression policies.
"We're talking about very, very small pockets of the city where police now consult with gang intervention workers. We have many years to go on this. But the time is clearly ripe for change at the LAPD," said Tom Hayden, the veteran anti-war activist from the 1960s who has himself brokered gang truces in his career as a California state senator and consultant to the LA Mayor's office.
The city spends no more than $4m (£2m) on gang intervention, compared with hundreds of millions of dollars on suppression policies, Mr Hayden said. But Mayor Villaraigosa is impressed with what he has seen so far and is willing to consider expanding the number of intervention workers into the hundreds.
Those workers tend to be overworked and underpaid, but often have a strong personal motivation to "save" the neighbourhoods where they grew up – neighbourhoods blighted by drugs, poverty, poor schools and even poorer employment prospects.
In Watts, scene of LA's first big race riot in 1965, a gang task force bringing together police, gang interventionists, ordinary residents and the local city council members, has met regularly since the beginning of last year. Two troublesome police officers have since been transferred out of the area and an initial deep mistrust has been replaced with a spirit of co-operation.
Mr Hayden argued, however, that the LAPD was still a long way from accepting such notions of community policing.
"Chief Bratton may be in favour of more funding for intervention and prevention, and that's a good thing," he said, "but he still frequently calls anybody that's a supporter of intervention work a 'thug-hugger'... The LAPD acceptance is uneven."