The outside police force investigating a fatal shooting involving two RCMP officers in British Columbia have released more details about what they believe happened during the deadly confrontation.

The Calgary Police Service was brought in to investigate the death of a 50-year-old man who was shot and killed during a confrontation with two Mounties last Friday in Kamloops.

While police haven't released the man's name, the victim's mother has identified him as Wilbert Bartley.

Calgary police say in a news release that their investigation has determined two plainclothes RCMP officers positioned an unmarked minivan behind an SUV, which then reversed and rammed into the police vehicle.

The news release says the officers fired two shots into the windshield of the SUV, hitting the driver once; the SUV then drove forward into a business, which has previously been described as a coffee shop.

The victim's mother, Catherine Bartley of Owen Sound, Ont., has acknowledged her son had a "lengthy" criminal record, but she has insisted he wasn't a violent man.