TORONTO -- They lived entirely separate lives but the circumstances of their deaths were strikingly similar.

Three Toronto-area residents who were gunned down by police at different times over the past three years were all thought to be experiencing mental health issues when they approached officers with sharp objects.

The province's police watchdog later cleared authorities of wrongdoing in all three cases, prompting calls for justice from the families of those killed.

A coroner's inquest that begins this week will now take a hard look at the lives and deaths of Reyal Jardine-Douglas, Sylvia Klibingaitis and Michael Eligon -- a process which is expected to raise questions about police use of force and how front-line officers deal with the mentally ill.

"I hope there will be a very strong message in the form of various recommendations to police that they must attempt de-escalation in any situation where it's feasible," Peter Rosenthal, a lawyer for the Eligon family, told The Canadian Press.

"The problem, I think, is that no police officer to my knowledge has ever been disciplined for failing to de-escalate a situation. In my view the police have to be properly policed."

Eligon died in February 2012 after fleeing from a Toronto hospital, where he had been involuntarily admitted under the Mental Health Act. The 29-year-old was dressed in a hospital gown and armed with two pairs of scissors at the time.

His father has said there didn't appear to be any justification for the death of his son, who he described as a non-violent man who had a child of his own.

The province's police watchdog ruled there were no grounds to charge the officer who shot Eligon.

Rosenthal said he wasn't looking for new weapons like Tasers -- which all front-line officers in Ontario can now carry -- to be suggested as a better way to deal with someone like Eligon.

"People mistakenly believe that if police have Tasers they use them instead of firearms -- they won't. They'll use them in addition to firearms," he said. "It's not weapons that are needed. It's approaching people in a reasonable way that's needed."

A better approach to dealing with the mentally ill, particularly when police have been alerted to their condition, is what Jardine-Douglas's family is looking for as well.

"This is a family that called the police for assistance when their son jumped on a bus because he was trying to avoid an examination at a hospital," explained lawyer John Weingust.

"An hour later (police) come back and they said 'Your son is dead.' We were completely shocked by it."

Twenty-five-year-old Jardine-Douglas died in August 2010 after pulling a knife out of his bag and advancing on an officer when police confronted him on a public transit bus for acting irrationally.

"The police are alleging self defence in this particular matter...There's something wrong with that type of training which appears to be shoot first and ask questions later. Something has to be done," said Weingust.

"The family misses their son very much. We intend to show that he was not a violent person."

In Klibingaitis's case, the 52-year-old called 911 herself in October 2011, saying she was going to commit a crime. When officers went to her house, she walked toward police with the knife in her hand in what the SIU described as a threatening manner.

She did not drop the knife in response to officers' demands and when she moved closer she was shot.

The SIU called her death a "tragic event" but said the officer was justified in using lethal force under the circumstances.

The inquest into all three deaths comes on the heels of another police shooting that claimed the life of a Toronto teen. Sammy Yatim, 18, was killed on an empty streetcar on July 27 in an incident that sparked public outrage over police use of force.

Yatim's case led Toronto's police chief to order a review of use-of-force policies which has been described as "extraordinary in scope." The incident also triggered an investigation by Ontario's ombudsman into what kind of direction the provincial government provides to police for defusing conflict situations.

But those in the policing world say people need to realize officers always strive to keep the public safe.

"We have become the first call for help and the last resort when help can't be found elsewhere. As such we are dealing with the full range of human issues, not just crime," said Dave McFadden, president of the Police Association of Ontario.

"More often than ever before, police are challenged to deal with the social issues that mental illness presents in a community and which can present as criminal and violent behaviour threatening the safety of the public and officers."

It's not that police don't want to deal with the mentally ill in the best possible way, said one observer, it's that they often don't have the resources to do so.

"The police are totally on board, it's the politicians and the legislatures have to put this in writing and then put some money behind it," said Rick Parent, a former officer who teaches police studies at Simon Fraser University.

Different forces also have different levels of training and support when it comes to dealing with the mentally ill, which can result in a patchwork approach, said Parent.

Some forces, like the Vancouver Police, have a mental health care liaison on call at all hours which can conduct on-site assessments and interventions, a force in Delta, B.C., has an officer who proactively contacts those with mental issue who might pose a problem in the future and some forces offer extensive officer training.

Many other forces, however, have little to no resources -- and even if they did it doesn't take away from the fact that other parties -- like hospitals, community housing and caregivers -- need to deal better with the mentally ill, said Parent.

"The police are at the rear end," he said. "We can train them as much as we can and give them all these less lethal weapons, that's not the solution. The solution is to deal with these individuals at the front end and to continue to deal with them and don't let them down."

The public also needs to realize that the police aren't perfect, said Parent.

"Police will always make mistakes," he said. "We have to limit the risk or limit the liability that we place police officers in. And we haven't been doing that. We just kind of throw them out and hope for this flawlessly perfect situation."

The inquest, which begins Tuesday in Toronto, is expected to last eight weeks and will hear from more than 50 witnesses.

A jury may make recommendations at preventing similar deaths but is not tasked with finding fault or laying any blame.