Originally Published: 11 AUG 22 07:26 ET

By Nicquel Terry Ellis, CNN

(CNN) -- When Frances Garrett lost her mentally ill daughter to police violence in 2014, she channeled her grief by demanding change.

Garrett said Phoenix police fatally shot Michelle Cusseaux at her apartment after she threatened officers with a hammer. Police, Garrett said, were not properly trained to respond to someone like Cusseaux, who was schizophrenic.

"Police are not professionals on mental health or mental illness," Garrett told CNN. "A person that is schizophrenic, paranoid, the first thing they do when they see an officer in a uniform is panic. They resist."

Garrett successfully lobbied for the city to improve its response to reports of people having mental health crises. In 2017, Phoenix rolled out a "mental health squad" comprised of officers who receive special training in crisis intervention, negotiation and tactical skills designed to diffuse situations with mentally ill people.

"They made changes," Garrett said. "I wanted to prevent it from happening to anyone else."

While Phoenix police have made changes, across the country, mentally ill people continue to die at the hands of police or in police custody.

The family of 28-year-old Brianna Grier says she was having a mental health episode in July when she was arrested in Georgia before falling out of a police car and dying. Investigators concluded that the rear passenger side door of the patrol car, near where Grier was sitting, was never closed. Her funeral is set for Thursday at West Hunter Street Baptist Church in Atlanta. The Rev. Al Sharpton will deliver the eulogy.

Experts say deaths like Grier's underscore a larger issue of whether police are properly trained and equipped to respond to reports of people having mental health crises.

A study conducted by the Treatment Advocacy Center found that people with untreated mental illness are 16 times more likely to be killed during a police encounter. It also found that those with untreated mental illness were involved in at least 1 in 4 fatal police shootings.

The risk for Black people with mental illness is even higher, experts say.

Calls for a nationwide solution

In addition to Phoenix, cities including Denver, New York and Chicago have piloted mental health emergency responder programs. But advocates are calling for a nationwide solution that requires all police to be trained on how to handle mental health crises. Some have also proposed partnerships with mental health professionals who can respond around the clock to reports involving mentally ill people.

Johnny Rice, associate professor of criminal justice at Coppin State University, said he believes in a multi-layered approach for law enforcement.

All officers should have mandatory training and community-based mental health counselors should assist them on calls involving mental health episodes, Rice said.

The training should also include lessons on cultural sensitivity, he said. People of color with mental illness are often already dealing with trauma and existing community violence that law enforcement should consider when responding.

"The stigma of mental illness can't be something that influences response," Rice said. "It has to be officers who have a sensitivity and awareness of the issue and also understand that they have resources and tools that can assist them to ensure that a person does not harm themselves or others."

The risks of police presence

Some mental health advocates say police should not even be involved in the response unless the mentally ill person is armed and a threat to others.

Earlier this year, a national "988" crisis line was rolled out to connect callers with crisis prevention services. A 24-hour call center fields the calls and dispatches teams to respond to suicidal crises or mental health-related distress.

Lauren Bonds, legal director for the National Police Accountability Project, said police are not qualified mental health professionals and their presence during a mental health crisis is a high risk because they are armed.

Bonds noted that police are trained to respond to perceived violence or erratic behavior using force. She said the "co-responder" programs where both police and mental health professionals show up together have not been successful either: Officers still take control of the response, which leaves the risk of police violence.

"I think the best response is to have a purely civilian crisis intervention team that families are able to call in these situations," Bonds said. "They always have the option to bring in the police after they have assessed the situation. But I think keeping police out of it, at least for the initial assessment, and giving families the opportunity to know that they can get help for their loved one without the potential for a police officer killing their loved one is really important."

In Grier's case, her family said she had a history of mental health episodes and they had called police on several occasions. Her father, Marvin Grier, said the police would typically call an ambulance service to transport Grier to a hospital for help. But on July 15, Hancock County Sheriff's deputies came alone, handcuffed Grier and placed her in the back of the patrol car to take her into custody for allegedly resisting arrest.

In addition to the door not being closed, family attorney Ben Crump alleges that police didn't secure Grier in a seat belt while she was handcuffed in the back of the police car.

"If we knew what we know now we wouldn't have called them (the police)," Marvin Grier told CNN. "We would deal with what was going on with her alone and she would have been here. It's a bad situation how our daughter left here in good shape and ended up (dead)."

There are also striking racial disparities with police encounters.

Black people are three times more likely to be killed by police than White people, according to the Harvard T.H. Chan School of Public Health. Some research suggests that the risk of death increases for Black people who show signs of mental illness.

West Resendes, a staff attorney for the ACLU, said the stigma around mental illness makes Black communities -- which suffer from overpolicing and higher incarceration rates -- even more vulnerable.

"When we add the intersectional layer of mental health disability to that, it exponentially increases the likelihood of that individual having adverse contact with law enforcement," Resendes said.

The need for better systems

Law enforcement experts agree that police officers are not properly trained to handle mentally ill people.

Diane Goldstein, a retired lieutenant from the Redono Beach Police Department in California, said police should be the last agency to respond to a mental health call unless weapons are involved and lives are in danger.

When police respond and the situation escalates, there is a possibility that someone could be harmed, she said. But people continue to call police because, in most cases, there is no alternative, Goldstein said.

There hasn't been enough investment in infrastructure to ensure there are mental health workers available 24 hours a day and enough beds in psychiatric units to accommodate people, Goldstein said.

She called for lawmakers to budget more money for community health and safety.

"We can't create systems without investing heavily in mental health infrastructure," Goldstein said. "We don't have systems and that is not law enforcement's fault."