LONDON — Amid the protest wave following the death of George Floyd in Minneapolis, the rallying cry of "defund the police" has gained momentum.

President Trump is “appalled” by the movement, according to White House spokeswoman Kayleigh McEnany. To some critics, it sounds radical.

But advocates say it is simply about narrowing the role of police and investing in services specifically designed to address issues such as mental health, rehabilitation and homelessness.

Social issues common theme

What would that look like? Possibly like Stockholm’s mental health ambulance service? Or Scotland’s violence reduction unit? Switzerland’s alternative sentencing approach or Finland’s housing-first strategy?

Much of what U.S. advocates are calling for has been tried in other countries, researchers say, offering models that the United States could consider and potentially adapt.

“There’s absolutely scope for the U.S. police forces to take a more integrated approach to how they serve their communities,” said Megan O’Neill, an expert on community policing at the University of Dundee in Scotland.

She said that in most European countries, policing isn’t viewed primarily from a top-down, law-enforcement perspective, but rather as part of a bigger solution to social problems. “It’s not: There’s a problem, send the police. It’s: There’s a problem, let’s work together to find a solution,” she said. “Policing is seen as a small part of a bigger set of actors in terms of addressing social issues.”

But O’Neill said advocates shouldn’t underestimate cost.

“What’s missing from current discussions is we can’t just take money from policing and put it somewhere else,” she said. “The whole system needs to be very well-resourced; this kind of work is expensive. . . . There’s an argument that savings will come later, but it will have an upfront cost.”

“For a U.S. audience, the key message is: Fund public services,” said Elizabeth Aston, director of the Scottish Institute for Policing Research.

Sweden: Health teams instead of police

Budget cuts to psychiatric services in the United States have resulted in police taking on a greater role in dealing with the mentally ill. An estimated 10 percent of police encounters involve people affected by mental illness. A Washington Post analysis found that 25 percent of those shot and killed by police in the United States in a six-month period in 2015 were in a mental health crisis.

Some communities have embraced “crisis intervention teams” made up of police officers who have received extra training to understand and respond to mental health crises.

But newer approaches involve sending mental health professionals along with — or instead of — police into situations involving mental health emergencies.

In Sweden, mental health professionals have been deployed since 2015 onto the streets of Stockholm without police officers.

“If a patient has an emergency psychiatric issue, it should really be dealt with by trained health professionals,” said Andreas Carlborg, managing director of the North Stockholm Psychiatry.

Stockholm’s mental health ambulance — an emergency vehicle with two trained nurses and a driver — seeks to free up police resources, to allow officers to focus on fields they are the experts in, Carlborg said.

On a typical shift, the ambulance is dispatched to five or six emergencies.

An academic analysis concluded that the project gave patients the impression of creating “a safe environment” and an “open and safe place for dialogue.”

Scotland: Violence as public health issue

In 2005, Glasgow was dubbed the “murder capital of Europe.” Exasperated by the city’s high homicide rates and its notorious booze-and-blade culture, police decided to try something new. They set up a violence reduction unit with a philosophy that violent behavior spreads from person to person; to contain it, you need to interrupt transmission and focus on prevention.

Doctors, nurses, paramedics and oral surgeons travel to schools around Scotland sharing graphic stories about patching people up after knife fights. Former offenders patrol emergency hospital wards looking for people at a “reachable moment.” Inspired by a youth program in Los Angeles, the police also set up cafes called Street and Arrow, which are staffed by former offenders who gain work experience and have access to on-site mentors.

Glasgow’s homicide rates have dropped dramatically, and although it’s unclear how much of that decrease should be attributed to the violence reduction unit, the model has drawn interest from police forces as far away as Canada and New Zealand.

Switzerland: Alternatives to prison

With one of the world’s highest incarceration rates, the United States has faced frequent criticism from abroad over its approach to justice — and the impact on reoffending rates.

Some countries are looking at a different path: keeping many first-time offenders from having to go to jail at all.

Switzerland restructured its justice system in 2007, after its authorities found that short prison sentences do little to deter criminals from reoffending and can even have the opposite effect.

“Farewell to prison,” read a 2007 headline for an article in Switzerland’s conservative Neue Zürcher Zeitung discussing the changes. Whereas convicted thieves were far more likely to receive a prison sentence than a fine or community service sentence in the year before the change, the opposite has been true since.

Other proposals include permitting daytime work release for prisoners with short sentences, allowing them to keep their jobs.

Finland: Homeless help

Finland is the standout example in Europe for its handle on homelessness.

As a starting point, it offers homeless people a permanent, stable home. From there, the former homeless are offered access to other support services, such as help with addiction and advice on work placements. Finland is the only country in the European Union where homelessness is on the decline. Since launching its “housing-first” program in 2008, the number of long-term homeless has dropped by more than 42 percent. There is only one 52-bed shelter in all of Helsinki.

The approach to homelessness isn’t police-led, but it has helped to stop the cycle of people coming out of prison or struggling to get clean and not being able to find a home, advocates say. People in the program also get access to support, which can help reduce reoffending and substance abuse.

Juha Kaakinen, one of the architects behind the idea and the head of the Y-Foundation, Finland’s largest housing nonprofit, calls housing a “human right.”

The country’s criminal policy goal is often summed up in a slogan: “Good social development policy is the best criminal policy.”

England and Wales: Independent oversight

England and Wales have 43 police forces, which are overseen by Her Majesty’s Inspectorate of Constabulary, an independent body that carries out inspections, writes reports and makes recommendations.

Lawrence Sherman, a criminologist from the University of Cambridge, said that this oversight body can, effectively, defund the police by withholding roughly half of the police budget. The threat of that sanction, he said, helps to concentrate minds of local police chiefs.

“The question of how you keep a rogue department under control shouldn’t have an answer that says, ‘Get the right police chief,’ ” Sherman said. “The answer should be: Have a high-level large population electorate overseeing a regulatory process that is applied impartially, without fear or favor, or local friendships.”