Quebec's independent police watchdog needs to be more transparent and its operations should be investigated by a legislative committee, rights advocates and victims' families said Monday.

The group, led by a civil rights advocacy organization called la Ligue des droits et libertes, also questioned whether the office is as independent as it claims to be.

Quebec's police watchdog, known as the Bureau des enquetes independantes, was created in 2016 following years of complaints and demands from citizens for an independent bureau to investigate instances when someone dies or is seriously injured during a police intervention.

On Monday, rights advocates and the families of people killed by police lamented the lack of criminal charges that have resulted from the BEI's investigations and they called for a legislative committee to study the office's first three years of operation.

Tracy Wing's 17-year-old son, Riley Fairholm, was killed by police in Lac Brome, Que., in July 2018. He was in the parking lot of an abandoned restaurant with an air pistol.

She told reporters Monday when BEI officials interviewed her, "they convinced me their investigation would be rigorous and done with integrity and transparency." But her trust in the BEI was lost after she met witnesses to her son's death who were never contacted by the BEI -- even after she alerted the office to them.

When the BEI published a short press released describing the "facts" surrounding her son's death, she said none of the information told to her by the witnesses was included.

"I have two questions for the minister," said Wing, referring to Public Security Minister Genevieve Guilbault. "When will the public be informed about the version of events from witnesses and not just from the police? And, what is happening in the BEI?"

Cesur Celik and his wife saw their son killed by police in front of them at their Montreal-area home in 2017. The 28-year-old was intoxicated and wanted to use the car. His parents called 9-1-1 to stop him.

According to the victim's father, police arrived and immediately tried to physically subdue his son. They allegedly hit him and repeatedly beat him with their feet and knees.

Cesur Celik said he saw "a flash" and then the police stopped beating his son.

"After the flash, they stopped and we asked ourselves why," he said. "We hoped it would be the end of the violence, but that wasn't why they had stopped. It was because our son was dead."

He questioned why three former Montreal police officers were part of the team dispatched by the BEI to conduct the investigation. Celik also wondered why the office published a news released about the incident that didn't include the fact the victim's parents witnessed their son being killed.

"They only included the version of the police," Celik said.

The BEI has initiated 90 criminal investigations of Quebec police officers since it began operating in June 2016. Of those, 42 resulted in no charges and 43 remain open. Two officers have been charged with sexual assault and three files are being studied by prosecutors.