When police in Rochester, New York, apprehended a Black man named Daniel Prude in March, he was going through a mental health crisis. He was dead shortly after police subdued him with a so-called "spit hood."

Police say he died from "complications of asphyxia in the setting of physical restraint." The Rochester police chief and command staff resigned recently.

Experts say up to a quarter of people killed by police officers have some sort of mental illness. And about 40 percent of adults with serious mental illness will come into contact with the criminal justice system during their lifetimes.

So does the U.S. need to rethink policing and mental illness?

One city that has already done that is the Swedish capital, Stockholm. Since 2015, a mental health ambulance has been on hand to deal with emergency psychiatric issues.

Andreas Carlborg is the managing director of North Stockholm Psychiatry, and helped create the mental health ambulance service there. He spoke to The World's host Marco Werman about what the U.S. could learn.

Marco Werman: What kind of cases is the mental health ambulance used for in Stockholm?

Andreas Carlborg: So, when we started this project in 2015, the main first priority case was suicidal behavior. But in reality, we now deal with quite a broad spectrum of psychiatric disorders — everything from acute psychosis, delusional behavior with agitation, as well as serious suicidal behavior.

And when an individual is in a situation like this and somebody calls you, are they calling the police or are they calling the mental health ambulance? How are you alerted?

What will happen is there is a common number — the alarm center — that will take the call from maybe the public or the patient or relatives or whatever, and then they will dispatch their psychiatric care ambulance and, in some cases, also the police. So they will decide whether this is a case for psychiatric emergency services.

And how is the mental health ambulance staffed? Who's inside when it shows up?

The ambulance is staffed with three people: two nurses that are specialists in psychiatric care, and then there is also ambulance driver with specific knowledge of ambulance services and emergency services in the region.

So the service, the mental health ambulance, has been operating since 2015. Why was it created?

Well, there were actually two issues. One was that the patient and the patient organizations felt that they didn't receive the proper medical assessment because they were usually dealt with by the police. And the police were frustrated because they felt that they had to deal with issues that they didn't have the proper training for and didn't really have the time to spend on it. So, I would say that was two of the main factors that motivated us to start this project.

You have, no doubt, heard the calls to defund the police in the U.S. What a lot of people are really talking about is reallocating resources to city departments that can do jobs like mental health care that police may not be trained to do. Did Stockholm have that debate when the mental health ambulance was proposed? Or was it about deviating resources from the police department to another department?

No, not really, because this ambulance wasn't about taking resources from the police to the emergency psychiatric services. But at the same time, that police felt, and are still feeling, — but less so — that a lot of their resources are used to deal with psychiatric patients outside in the public. So, this was something that they raised and felt that was a really big problem for them.

In cases where police do accompany the mental health ambulance staff, what kind of cases — is it for violent cases?

Yeah. So in about 50 percent of the cases that the ambulance deals with, there will be cooperation with the police. In some cases, the patient can have a history of violent behavior and that would be a reason for bringing in the police with them. And sometimes that police are also dispatched by the alarm center along with the psychiatric ambulance. But in most of the cases, the police can leave and the patient will be taken care of fully by the staff in the ambulance.

What's been the overall effect of having the psychiatric ambulance in Stockholm?

First of all, if you look from the patient's perspective, the patients have really felt that there's less stigma of having these problems. The quality of the care provided outside a hospital setting has increased because now they are taken care of by trained health care professionals instead of the police.

Also, the police have communicated that they feel that this is a big relief for them because they now have access to health care professionals in the pre-hospital setting that can, in most cases, deal with these patients and take care of them in a proper way. Previously, when the police handled that, they would always take these patients to the [emergency room]. Now we can let about 30 percent of the patients go after being assessed by the neurosis, they can stay at home and we can provide them with contact to an outpatient clinic and prepare them so they can have a proper followup in an outpatient setting.

Is there just one or several ambulances now?

The project started in 2015. But after about one year, it was decided it should be a regular part of the emergency medical services in the region. So, there is one ambulance that can start on its operation from 2 o'clock in the afternoon to 2 o'clock at night. That's where we have most of the alarms coming in. There is room for another ambulance in the region, but it's hard to find proper staff with the right knowledge. But in the near future, we might start up another.

This interview has been edited and condensed for clarity.

This article originally appeared at PRI's The World.