Several justice groups want an outside review of an investigation by B.C.'s independent police watchdog that cleared RCMP in the fatal shooting of a former Canadian soldier after conflicting reports about whether the man was shot in the back or in the chest.

A coroner's inquest has heard Greg Matters was shot in the back by a member of the force's emergency response team, but the report by the Independent Investigations Office says he was shot in the chest. The discrepancy raises questions about the investigation, say the B.C. Civil Liberties Association, Pivot Legal Society and Justice for Girls.

"The evidence in question... is crucial and basic," said the letter sent Thursday to agency director Richard Rosenthal.

No matter whether the evidence would change the finding of the investigation team, it is a fact that should have been publicly reported by the independent civilian agency, it said.

"The fact that your public report fails to present this evidence accurately raises significant questions about your investigation into the fatal shooting of Mr. Matters by the RCMP."

Matters's family echoed the call.

"This fact is crucial to the IIO's investigation and it raises questions as to whether or not criminal charges should be reconsidered," said Tracey Matters, his sister.

Matters was shot on the rural property he shared with his mother near Prince George, B.C., on Sept. 10, 2012, by a member of the ERT team sent to arrest him on a charge of assaulting his brother.

The 40-year-old former peacekeeper was in treatment at the time for post-traumatic stress disorder, and a coroner's inquest into his death heard that he'd had several run-ins with police and a criminal conviction related to threats he made in an email to the head of the RCMP public complaints commission.

Officers testified at the inquest that they were aware that Matters, a 15-year soldier who served in Bosnia, suffered from PTSD.

Matters's death was the first to be investigated by the newly minted Independent Investigations Office, the civilian agency that investigates all police-involved deaths or cases of serious injury in B.C.

3 versions of events given

In a report released publicly last May that found no criminal wrongdoing on the part of the officers involved, the agency said "an ERT member shot Mr. Matters with two bullets to the chest."

The full report by the IIO has not been released, but the groups say Rosenthal offered a third version of events: that Matters was shot in the chest and in the back.

The pathologist testified at the coroner's inquest only that Matters was shot twice in the back, demonstrating the entry wounds to the jury.

Owen Court, spokesman for the watchdog agency, has told The Canadian Press that the agency may issue a supplemental report after the coroner's inquest into Matters' death concludes. The inquest originally slated for a week adjourned after two weeks of testimony and will resume in January.

"The IIO was provided with a complete copy of the autopsy report, which listed the cause of death as `gunshot wounds to chest'," Court said in an email last week when the discrepancy was first revealed.

"At the conclusion of the inquest process, we may issue a supplemental report confirming that bullet paths were known to the IIO and considered... as part of his decision in this case."

Josh Paterson, executive director of the civil liberties association, said a supplemental report is not good enough.

"We think it's important there be an independent look at this case to see what exactly happened, why that error was made, and whether or not, in light of the more accurate evidence, will there be any change in the IIO conclusion," Paterson said.

Independence, competence questioned

The groups hope Rosenthal will order that review. If that doesn't happen, they may appeal to the province's attorney general.

"It's in everybody's interests that there be full confidence in what the IIO is doing," Paterson said.

"There needs to be more than a simple explanation from the IIO... There needs to be a truly independent review of what happened and we think that's really the only way of ensuring that public confidence is maintained."

Tracey Matters said the testimony from the pathologist at the inquest has raised other questions about whether her brother could have had a hatchet raised in his hand, as the RCMP has said.

Annabel Webb, director of Justice for Girls, said her group has been lobbying the government to extend the IIO mandate to include allegations of sexual abuse against police officers.

The difference between the IIO report and the testimony at the coroner's inquest shakes public confidence in the agency, she said.

"That is a huge discrepancy and one that needs to be explained," Webb said.

"Either there is an issue of competence or there is an issue of independence. It's hard to tell at this point how this could have happened."

Webb said while the civilian agency has been a welcome arm's-length oversight of police in B.C., she said she has long had concerns that almost all of the investigators at the office are former police officers.