Terror-attack warnings received in the days before the Oct. 22, 2014, assaults at the National War Memorial and in Parliament were not specific enough for the RCMP to stop the shooter, says the commissioner of the Mounties.

Bob Paulson was reacting Thursday to a CBC News story that said the Mounties had received three separate terror-attack warnings in the five days before Michael Zehaf-Bibeau shot dead a sentry at the war memorial, then stormed Parliament Hill where he died in a hail of gunfire in the hall of honour.

"There was no specific threat that said, 'Hey, there's a guy named Bibeau who's going to come shooting and run up on the Hill,'" Paulson said at a downtown Ottawa memorial service marking the tragedy.

"That said, we responded to those elevated threat levels."

RCMP Commissioner Bob Paulson arrives at a Senate committee in May 2015. Paulson says terror-attacks warnings received before the Oct. 22, 2014, shootings in Ottawa were too vague to stop the attacker. (Adrian Wyld/Canadian Press) Internal documents obtained under access to information show the force distributed three warnings, the first on Oct. 17 alerting all security personnel to potential terror attacks, and raising Canada's threat level to medium from low. None of the documents identified likely dates, locations or targets.

Security experts have also said that without more precise details, it is difficult to act apart from instructing officers about an elevated threat level that requires precautions.

Chronic shortages?

The documents also outline chronic staff shortages in the RCMP unit that's responsible for Parliament Hill security, which had at least 29 vacant positions last fall. The unfilled posts were the result of budget cuts in the Harper government's 2012 budget.

Paulson acknowledged the staffing crunch, but said there were no positions unstaffed on the Hill the day of the shootings "and no shortage of patrols that day."

A police car blocks a street in Ottawa on Oct. 22, 2014. (Sean Kilpatrick/Canadian Press) "The staffing of Parliament Hill security has been a multi-year struggle," he said. "It's true that on the overall strength of the RCMP contingent there, there were vacancies."

RCMP emails dated Oct. 19, 2014, show that the RCMP had instituted "enhanced patrols" after two minor security incidents, but that these were ended on Oct. 20.

"I suggest we resume regular operations as of tomorrow morning. Any concern?" Supt. Luc Lemire wrote to his boss. "Agree," was the response 10 minutes later.

Paulson, however, denied that any patrols were stepped down in the two days before the shootings.