Cities across America are moving to copy an initiative introduced in California: paying criminals up to $1,000 (£700) a month not to commit another gun crime.

The controversial approach launched in Richmond, a working-class suburb in north San Francisco, is claimed to have helped to reduce murder rates, some say by half. But the programme requires governments to reject some basic tenets of law enforcement and challenges notions of appropriate ways to spend tax dollars.

In Richmond, the city has hired ex-convicts to mentor dozens of its most violent offenders and allows them to take unconventional steps if it means preventing the next death. For example, the mentors have coaxed inebriated teenagers threatening violence into city cars, not for a ride to jail but home to sleep it off – sometimes with loaded firearms still in their waistbands. The mentors have funded trips to South Africa, London and Mexico City for rival gang members in the hope that shared experiences and time away from the city would ease tensions and forge new connections.

And when the elaborate efforts at engagement fail, the mentors still pay those who pledge to improve, even when they are like 21-year-old Lonnie Holmes, who was caught with a gun, or are suspected of murder. The city-paid mentors operate at a distance from police. To maintain the trust of the young men they are guiding, mentors do not inform police of what they know about crimes committed.

And yet, interest in the programme is surging. Officials in Miami, Toledo, Baltimore and more than a dozen cities in between are studying how to replicate Richmond’s scheme.

The famous for and against US gun control Show all 31 1 /31 The famous for and against US gun control The famous for and against US gun control Against: Robert De Niro Despite the actor being a gun-wielding fast-talker, he told Daily Mail: "There should be more control. It has just gotten out of hand, how easily you can get guns." The famous for and against US gun control For: Brad Pitt "America is founded on guns. It;s in out DNA. It’s very strange but I feel better having a gun." Getty Images The famous for and against US gun control For: Angelina Jolie "Brad and I are not against having a gun in the house, and we do have one. If anybody comes into my home and tries to hurt my kids, I’ve no problem shooting them." AFP/Getty The famous for and against US gun control For: Johnny Depp "When I was a kid it was a controlled atmosphere, we weren't shooting at humans - we were shooting at cans and bottles mostly. I will most certainly take my kids out for target practice." Getty Images The famous for and against US gun control For: Bruce Willis "Everyone has a right to bear arms. If you take guns away from legal gun owners, then the only people who have guns are the bad guys." Getty Images The famous for and against US gun control For: Clint Eastwood "I have a very strict gun control policy: if there's a gun around, I want to be in control of it." Reuters The famous for and against US gun control For: Whoopi Goldberg "I’m an NRA member, as you know or probably don’t know... I want to know that there’s at least some way to prevent folks who are just getting out from mental institutions [from getting guns]." The famous for and against US gun control For: Vince Vaughn "Banning guns is like banning forks in an attempt to stop making people fat. Taking away guns, taking away drugs, the booze, it won't rid the world of criminality... I support people having a gun in public full stop, not just in your home." Getty Images The famous for and against US gun control For: Donald Trump "Democrats want to confiscate all guns, which is a dumb idea because only the law-abiding citizens would turn in their guns and the bad guys would be the only ones left armed. The Republicans walk the NRA line and refuse even limited restrictions" Getty The famous for and against US gun control Against: Matt Damon “I actually hate guns. They freak me out.” Rex The famous for and against US gun control Against: Mark Wahlberg "Well, I would love it if they could take all the guns away. Unfortunately, you can’t do that so you hope that good people in the world have them to protect the people who can’t protect themselves." AP The famous for and against US gun control Against: Sean Connery "It is said that a total ban on handguns, including .22s, would take away innocent pleasure from thousands of people. Is that more or less pleasure than watching your child grow up?" Rex Features The famous for and against US gun control Against: Arnold Schwarzenegger "I’m for gun control. I’m a peace-loving guy." Lionsgate The famous for and against US gun control Against: Sylvester Stallone "Until America, door to door, takes every handgun, this is what you’re gonna have. It’s pathetic. It really is pathetic. It’s sad. We’re living in the Dark Ages over there." Getty Images The famous for and against US gun control Against: Rashida Jones "Gun control is our only road to freedom. Freedom from the fear of senselessly losing children." Getty The famous for and against US gun control Against: Susan Sarandon "How much more suffering & loss will it take before we better regulate the sale of arms in our country?" Getty The famous for and against US gun control Against: Beyonce Queen B was part of the Demand a Plan campaign against guns after Newton shooting, by appearing in a video alongside a bunch of celebrities. AP The famous for and against US gun control Against: Jamie Foxx A Hollywood gang joined Beyonce in the campaign... GETTY IMAGES The famous for and against US gun control Against: Cameron Diaz Took part in the Demand a Plan campaign. Getty Images The famous for and against US gun control Against: Jessica Alba Took part in the Demand a Plan campaign. Getty Images The famous for and against US gun control Against: Jennifer Garner Took part in the Demand a Plan campaign. Getty Images The famous for and against US gun control Against: Jennifer Aniston Took part in the Demand a Plan campaign. Jason Merritt | Getty Images The famous for and against US gun control Against: Jon Hamm The Mad Men actor also appeared in the video... The famous for and against US gun control Against: Reese Witherspoon Took part in the Demand a Plan campaign. Getty Images The famous for and against US gun control Against: Ellen DeGeneres Took part in the Demand a Plan campaign. Reuters The famous for and against US gun control Against: Julianne Moore Took part in the Demand a Plan campaign. The famous for and against US gun control Against: Selena Gomez Took part in the Demand a Plan campaign. GETTY IMAGES The famous for and against US gun control Against: Peter Dinklage The Game of Thrones also appeared in the video... Getty Images The famous for and against US gun control Against: Zooey Deschanel alongside the New Girl star. Getty Images The famous for and against US gun control Against: Steve Carell Took part in the Demand a Plan campaign. Getty Images The famous for and against US gun control Against: Gwyneth Paltrow Took part in the Demand a Plan campaign, too.

The District of Columbia is the first in line. Implementing the model has emerged as a central fight this year between Washington DC’s Mayor, Muriel Bowser, and its council. Ms Bowser, a Democrat, argues that the city should use its resources to fund jobs programmes and that there is little independent analysis of the Richmond scheme. She did not include money for it in her 2017 budget. But this month, the council unanimously approved the idea as the best response to a surge of violent deaths that rocked the city last year.

Five years into Richmond’s multimillion-dollar experiment, 84 of 88 young men who have participated in the programme remain alive, and four in five have not been suspected of another gun crime or suffered a bullet wound, according to DeVone Boggan, the scheme’s founder.

In 2007, Richmond’s murder tally surged to 47, making it the sixth-deadliest US city per capita. In the 20 preceding years, 740 people died from gun violence. Politicians began to see this as a public health emergency.