A Quebec association representing families of people with mental illness is calling for more extensive police training, after two men were shot this summer.

Patrick Limoges and Mario Hamel were shot and killed by Montreal police during an early-morning confrontation on Sainte-Catherine Street in June.

Police said Hamel, a troubled man living in transitional housing, was causing a disturbance and threatened officers.

Limoges, an innocent bystander, was struck by an errant bullet in the standoff.

New information obtained by Radio-Canada's Enquête program reveals that Hamel had a substantial psychiatric history, and a criminal record for threatening his family.

But he was deemed not criminally responsible by virtue of his mental illness.

Hamel's family now wonders whether his death could have been prevented.

Watch Dan Halton's report HERE.