B.C.'s police watchdog is turning to the courts for help getting officers to cooperate with its investigation into a fatal shooting in East Vancouver.

The Independent Investigations Office has filed a petition in B.C. Supreme Court in the hopes of compelling seven officers to take part in interviews about the incident, which took place outside the Canadian Tire on Bentall Street in November.

Police opened fire on Daniel Peter Rintoul after the 38-year-old allegedly stabbed a store clerk, tried to steal firearms, held a senior hostage and stabbed an officer multiple times.

Months later, the IIO, which is tasked with probing all police incidents that result in death or serious injury, claims it has faced pushback when trying to question officers about what happened.

"They have demanded, through their counsel or union representative, pre-interview disclosure of certain investigative file materials in the IIO's possession as a precondition of any IIO interviews," the filing reads.

Those investigative materials include audio and video evidence gathered in the case.

The watchdog said it would be willing to share some of its evidence with police shortly before they're interviewed, but that it doesn't want to influence their memories of the incident.

Its court filing represents the first time the IIO has had to petition the courts for police cooperation, spokesperson Aidan Buckley told CTV News Friday.

The Vancouver Police Union is standing behind the officers, arguing they are only trying to ensure they give the most accurate accounts of the shooting as possible.

"What the IIO are proposing is that a member would show up and give an interview just from memory," union president Tom Stamatakis said. "People don't recall accurately every little detail around what they did in any incident, let alone one that unfolds very dynamically and in a very stressful manner."

The evidence officers are requesting is the same kind of materials they would consult before testifying in court or taking part in an inquiry, Stamatakis added.

"We're talking about their own notes, we're talking about radio transmissions, computer aided dispatch records and video if it depicts what that particular officer did," he said.

The union president also refuted the IIO’s characterization that police have been uncooperative, insisting that they're keen to sit down for interviews, under the right conditions.

Both the IIO and the Vancouver Police Department declined to comment on the matter while it's before the court.

"We respect the independent civilian oversight process. This is a complex legal issue that has been filed," Staff Sgt. Randy Fincham told CTV News in an email.

Josh Paterson with the BC Civil Liberties Association said it's important that the IIO be able to set the terms on which it will be interviewing witnesses, rather than allowing police to set them.

"As long as witnesses are telling the truth, witnesses are entitled to misremember things. They do all the time," he said.

Rintoul, a Vancouver resident who was originally from Alberta, did not have a criminal record, but police said he was known to them.

Few details about his shooting, including the numbers of rounds that were fired, have been publicly confirmed.

CTV News contacted a member of Rintoul's family, but they had no comment.

With files from CTV Vancouver's Maria Weisgarber