Quebec's Bureau of Independent investigators have sounded the alarm.
They're raising concerns that some SPVM officers aren't following protocol after being involved in a shooting.
23-year-old Nicholas Gibbs was shot dead by police in Notre-Dame-de-Grâce in August, after he allegedly threatened officers with a knife.
Police say they tried to subdue him with pepper spray, then tried tasing him, but when that didn't work, they fired five shots at him.
On Tuesday, a lawyer who represents the Gibbs family released a letter from the director of the BEI addressed to Montreal's police chief.
In the letter, Madeleine Giauque said police officers should not take statement from witnesses then show the statements to supervisors.
Quebec Public Security Minister Genevieve Guilbault said the police watchdog unit is doing their job.
“What I saw is Giauque did her work,” she said. “She warned Montreal police that there are some practices that need to be respected and she gave a polite reminder to the SPVM. I’m confident they will respect what they’re supposed to be doing.”
Gibbs' family has sued the city for $1 million in damages, alleging police used excessive force.