A Quebec man accused of killing a provincial police officer had a history of mental health issues and had been found not criminally responsible at least five times for past offences.

Isaac Brouillard Lessard, 35, was shot dead by police after he allegedly fatally attacked Sgt. Maureen Breau on Monday evening and left her partner injured in Louiseville, Que., about 100 kilometres northeast of Montreal.

Brouillard Lessard's lawyer, Yanick Péloquin, says his client was due to appear in May before Quebec's mental health review board Commission d'examen des troubles mentaux du Québec.

The review board found in March 2022 that Brouillard Lessard posed a "significant risk to public safety" but determined that the risk could be adequately controlled if he would be properly monitored.

That March 2022 decision is one of several issued by the board about Brouillard Lessard since 2014.

Court records show that Brouillard Lessard had been the subject of five not criminally responsible verdicts since 2014 for a variety of charges, including assault with a weapon and uttering threats.

Brouillard Lessard was under probation at the time he was alleged to have killed Breau, having pleaded guilty to a 2021 assault.

In April 2022, he was given a conditional discharge and sentenced to 200 hours of community service and two years' probation.