TORONTO -- A retired judge appointed by Toronto's police chief to look into use-of-force policies has stepped down from the review, citing conflict-of-interest concerns raised by victims' families.

Dennis O'Connor announced late Wednesday that he was withdrawing because he works for a law firm that also acts for the insurers of the Toronto Police Service in civil suits -- some of which include allegations of excessive and lethal force.

O'Connor was the associate chief justice of Ontario's Appeal Court for 10 years and conducted inquiries into both the Walkerton water tragedy in Ontario and the rendition and torture of Maher Arar, a Canadian of Syrian descent.

He said neither he nor Toronto Police Chief Bill Blair thought his association with Borden Ladner Gervais LLP would affect the advice he would give, but he decided to back out because he did not want the issue to distract from the review.

"After the announcement, we were surprised by the objections raised by lawyers for some of the victims' families to my conducting the review," O'Connor wrote in a statement.

"We had thought that I could structure and conduct the review to satisfy any concern but apparently not."

The probe follows not just the case of Sammy Yatim, who died last month after being shot by police on an empty streetcar, but several other fatal police shootings in recent years.

Blair said he understood O'Connor's decision and will make an announcement about the review on Friday.

A review by the chief of police is mandated under the Police Services Act in Yatim's death because the Special Investigations Unit is involved.

But Blair has said this review will be "extraordinary" in scope, looking beyond Yatim's case to include a review of international best practices.

Hundreds of people took to the streets in two marches since Yatim's death in late July to demand justice for the 18 year old, after his shooting was captured on surveillance and cellphone videos.

Nine shots can be heard on the videos following shouts for Yatim to drop the knife. The final six appear to come after Yatim had already fallen to the floor of the streetcar.

A coroner's inquest this fall will examine the deaths of three people who may have had mental health issues when they approached Toronto police officers with weapons and were shot and killed.

Reviews were conducted in all of those cases, Blair said, but they were internal reviews and this one is expected to be made public.

Ontario's ombudsman has also launched an investigation, probing what kind of direction the provincial government provides to police for defusing conflict situations.