In a damning new report tabled in Parliament, Suzanne Legault concluded that the practice establishes a "perilous precedent" of rewriting laws — one that could jeopardize the ability of authorities to prosecute electoral fraud or other government scandals.
Legault recommended almost two months ago that charges be laid against the RCMP for its role in withholding and destroying gun registry data.
But instead of Justice Minister Peter MacKay moving on the recommendation to lay charges, the Harper government rewrote the law, backdated the changes and buried the amendment in an omnibus budget bill.
MPs and senators should "look themselves in the mirror and decide whether they can, in their own integrity, actually vote in favour of those proposed amendments," Legault said in an interview.
"We could do the same thing after investigating potential electoral fraud. We could erase these things retroactively."
At issue are millions of records from the defunct long-gun registry, which the Conservative government voted out of existence in April 2012.
Legault found that the Mounties stonewalled a request for the registry data in March 2012 and later released only portions of the eight-million-plus records.
Legault was assured in writing by then-public safety minister Vic Toews that the RCMP wouldn't destroy records while her investigation continued. The RCMP, nevertheless, went ahead and destroyed the data in October 2012.
Legault filed a suit Thursday in Federal Court in an effort to preserve the rights of the unnamed complainant in the case, but she said the issue goes far beyond gun registry records.
Backdating changes to the law to make something legal that was illegal — and after a finding of wrongdoing — breaks new ground, she said.
"If we accept that this is legal, constitutional and — perhaps further — legitimate in our Canadian democracy ... then I think we could have done the same thing when (auditor general) Sheila Fraser investigated the sponsorship scandal" under the Liberals in the 1990s, Legault told The Canadian Press.
"We could have ousted her entire jurisdiction after the fact."
The RCMP insisted it has fully complied with provisions of the Access to Information Act.
"The RCMP would vigorously defend against any accusation of unlawful conduct in respect of the handling of this access to information request," spokesman Sgt. Harold Pfleiderer said in an email.
Under the provisions in Bill C-59, the Mounties won't have to defend anything.
The omnibus budget bill exempts any "request, complaint, investigation, application, judicial review, appeal or other proceeding under the Access to Information Act or the Privacy Act" related to those old records.
Legault said it's the fourth time she has provided evidence to the attorney general of Canada or a minister that there were grounds for criminal charges.
No charges have ever been laid under the Access to Information Act, despite past findings of blatant and illegal political interference in the workings of the system, which is designed to inform Canadians about the activities of their government.
Prime Minister Stephen Harper said the Mounties were just obeying the will of his majority government.
"The government, the Parliament of Canada, has already decided to abolish the long-gun registry," Harper said at an event in Windsor, Ont.
"The RCMP have acted fully within Parliament's intention in destroying the data in the long gun registry."
Harper asserted that the dispute is over contradictions between the Access to Information Act and his government's legislation to end the long gun registry. That is not the case.
In fact, the dispute revolves around the RCMP refusing to disclose gun registry data while the Conservative bill was still being debated and not yet law, then destroying records it knew were under an active investigation.
Liberal MP Wayne Easter, a former solicitor general, said the government appears to be blinded by its fixation on destroying all traces of the long gun registry. "They don't see the other implications here — and there are other implications."
Easter said the RCMP would not make a decision to withhold records without political direction or support.
"If they're complicit with the government in terms of destroying information against the law, what next will they be complicit with their political masters in? That's a huge, huge question."
Nonetheless, the Conservative move will be popular with gun advocates.
Eliminating the long-gun registry, which was part of a wider gun control initiative brought in by a Liberal government in 1995, has been a huge fundraising and vote-winning issue for the Conservatives over the years.
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