When a Georgia police officer shot and killed Anthony Hill outside of Atlanta earlier this week, their interaction followed the script of countless others before it.

Someone called the police to report that Hill, a black Air Force vet with a history of bipolar disorder, was running around a residential complex — naked. Police later said that he was acting "deranged" and that he lunged at the officer who shot him. Hill was unarmed and evidently in the middle of a mental breakdown, but he ended up dead instead of in a mental healthcare facility.

This is an increasing occurrence, as mentally ill people regularly fail to receive the care they need and end up in often deadly encounters with law enforcement.

In some cases, the actions of the mentally ill seem to be directed at provoking police — so much so that the phrase "suicide by cop" was coined to describe some of these killings, suggesting that these individuals are trying to get shot.

Earlier this month, Zach Tumin, a NYPD deputy commissioner in charge of the department's social media strategy, caused a firestorm when he tweeted: "This is a real problem, evrywhre. via @ThisIsFusion People off their meds r losing it &wlking into police bullets. http://www.tacreports.org/justifiable-homicides ..."

Tumin quickly tried explaining himself to angry critics, tweeting an apology of sorts: "It was a mangled way to say that encounters btw cops &the mentally ill take training, svcs,&treatment to keep all safe." He didn't respond to VICE News' requests for comment on his tweets or about the training, services, and treatment necessary to make those encounters safe.

But the suicide by cop idea does not justify the failures of both law enforcement and society at large to address mental illness, critics say. Most of the time there is little evidence, if any, that suicide was the intention.

Earlier this year, Matthew Hoffman was shot and killed by two San Francisco officers after he pointed a pellet gun at them in a police parking lot. Hoffman left behind an actual suicide note, telling police that they had "ended the life of a man who was too much of a coward to do it himself."

"Dear Officer(s), You did nothing wrong," he wrote on his cell phone. "I provoked you. I threatened your life as well as the lives of those around me. You were completely within your legal rights to do what you did. You followed protocols."

That someone could rely so confidently on the likelihood of police responding to provocation with fatal gunfire is interesting, particularly as a means of suicide, but most cases are far less clear.

"Someone deciding to kill himself and using the police as their means — I don't know how common that is, that's been hard to track," John Snook, deputy executive director at the Treatment Advocacy Center, which promotes mental healthcare, told VICE News. "What we've seen a lot more is someone with a severe mental illness, who's psychotic, doing things that in the moment seem like they are trying to get themselves shot. But the reality is it's not a conscious decision."

The group has been studying the role of mental illness in what law enforcement calls "justifiable homicides." While the data at its disposal is severely limited, it has found that at least half of the people shot and killed by police each year have mental health problems.

It also found that a third of fatal police shootings appear to be suicides by cop, but Snook was quick to qualify this estimate as murky.

'This is the worst part of their job, because they know this isn't a criminal, and that they're dealing with someone they shouldn't have to deal with. But the system has failed that person and the police department is stuck trying to figure something out.'

Police killings are reported inconsistently, if at all, across jurisdictions — a fact that many critics, including the FBI director, have pointed out in recent months. There's no comprehensive tracking of deaths at the hands of police. Among the reports that are logged, an understanding of the victims' mental status is even less clear.

People with mental issues confronting police officers who are poorly equipped to help them is a problem, but a failure to get treatment is at its root. In some states, Snook said, mentally ill individuals can't be treated unless they personally seek help, or until they have become a danger to themselves or others.

"So what we're seeing is more and more of these incidents where a person is obviously ill, his family has tried to get them help, and nothing can be done until they're so dangerous that they have to call the police, and unfortunately those situations often end in tragedy," he explained. "You basically have families sitting there, knowing this person is a ticking time bomb, and there's nothing they can do for them until they get so sick that they're not only dangerous but they are a clear and present danger. Then the family calls the treatment professionals and they say, 'We can't do anything now that they're clear and present danger, you have to call the police.' "

Police responding to those calls may or may not be competent to handle those situations, depending on each department's access to resources and training.

'One of the biggest things is not rushing, taking time, and that is very, very contrary to police culture.'

Departments with the most resources have officers go through different versions of crisis intervention training, learning about de-escalation, communication, and containment strategies similar to those used in hostage situations.

Some officers are given training to help them understand individuals with mental illness. They wear headphones that mimic the audio delusions a schizophrenic or psychotic person might hear, and have other officers try to give them commands.

"They realize how difficult it is to follow even simple directions when you have someone else yelling in your ear," said Snook.

More often, they are trained to use non-lethal alternatives to gunfire, like Tasers and Mace. But even officers who receive some training are quick to escalate certain situations.

"There's a tendency to skip the less lethal alternatives. Again, there's a data shortage, but we have a number of instances where it seems like the gun is the first weapon chosen," Claudia Center, a lawyer with the American Civil Liberties Union who specializing in disability rights, told VICE News. "It's good to have the Taser and the Mace but those are also very aggressive — they can be life-preserving but they can also be part of the escalation. They're not a magic pill."

More important is communication with the individuals in question and coordination with mental health professionals — and to slow down, something few officers are willing to do.

"One of the biggest things is not rushing, taking time, and that is very, very contrary to police culture," Center added. "The longer an episode goes on, the more you wait it out, the more likely it is that it will resolve peacefully."

A bigger issue, critics agree, is that the burden of mental illness shouldn't fall on police in the first place — corresponding with the fact that the mentally ill shouldn't end up in jail because of a lack of treatment options. In prison, where mentally ill people are locked up at an alarming rate, they are more likely to have their stay extended because of unruly behavior, more likely to be victimized, and more likely to hurt themselves, several studies have found.

Incarceration is designed to control behavior, whereas mentally ill people need treatment that neither correctional facilities nor police officers can offer.

"This is the worst part of their job, because they know this isn't a criminal, and that they're dealing with someone they shouldn't have to deal with," Snook said. "But the system has failed that person and the police department is stuck trying to figure something out."

Officers can manage such situations better, but making sure they are not the ones responding to mental illness demands a massive public effort and a cultural shift in the way society views such individuals.

"Training is great, crisis intervention training is so valuable, but at the end of the day this is a band aid on a gaping wound," he said. "If you have a law enforcement officer who's having to deal with these folks, you've already failed."