A nonsense letter. A wayward cube van. A threatening voicemail. A tractor with the key left in the ignition.

These were the infrequent and minor incidents recorded by the RCMP's parliamentary detachment as threats to the security of VIPs during the two years leading up to the tragic shooting on Oct. 22.

Through the Access to Information Act, CBC News obtained a dozen "occurrence reports" documenting these relatively tame security challenges on Parliament Hill — tame, that is, until gunfire erupted inside the Centre Block last fall, putting the prime minister and many MPs in real and imminent danger.

The mundane incidents in the months leading to the tragedy provide context to last fall's attack in which a lone gunman surprised RCMP officers as he ran, drove and darted up steps with a loaded rifle in hand.

Since the traumatic episode, the Harper government has warned of future threats in the capital and across Canada, and introduced legislation to give security agencies more power.

Cube van goes wrong way

Here's a typical VIP security incident, recorded by the RCMP on Oct. 16, just six days before the Oct. 22 attack:

"While at the South Drive exit, a cube van drove onto Parliament Hill and stopped as the driver made eye contact with Cst. Tagak. The driver wasn't aware this was strictly an exit and promptly backed out ... and drove to the proper entrance."

Another incident, on May 14 last year, involved a complaint from a House of Commons security officer "advising that a nonsensical letter (email) was forwarded to the prime minister and various ministers."

That same month, House of Commons security reported a threatening voicemail had been left for a cabinet minister, whose identity has been removed from the document, though the RCMP concluded there was no threat.

Altogether there were just 12 threat-to-VIP incidents in 2013 and 2014, according to the RCMP release package.

'It appears that the tourist ditched the small bag.' -— RCMP security report on discarded cocaine

CBC News also asked for all reports classified as "possession" of prohibited weapons or drugs. Here, too, there were only five such reports, all of them minor.

A visitor security-screening unit found two instances where people had canisters of pepper spray, which were confiscated. No guns or knives were reported.

Tourist's cocaine?

In another instance, on Aug. 8 last year, the parliamentary unit reported a bag of what appeared to be cocaine.

"No suspect was identified but it appears that the tourist ditched the small bag when he saw that he would be searched to enter and visit the Parliament building, so he tossed it on the carpeted floor, behind a door." The bag was slated for destruction.

There were also two other minor episodes of marijuana smoking on public property, one of which resulted in the arrest of two young males.

An RCMP spokeswoman cautioned that incident frequency and severity is not the only guide to assessing risk.

"Our security posture is not solely based on the number of occurrences but on ongoing threat assessments and vulnerability reviews in order to ensure that we have the capacity and capabilities to discourage attacks, proactively disrupt and effectively respond to active threats," Brigitte Mineault said in an email.

"Our approach is risk-based and factors in the likelihood of an incident but more importantly the potential impact."

Mineault declined to indicate how Parliament Hill security has been beefed up since Oct. 22, saying only there has been a "significant" increase in resources.

White House threats a chronic problem

Canada's experience of threats in recent years to the Parliament Buildings, where the prime minister keeps an office and where cabinet meets, is in contrast to that of the United States. Just this week, the U.S. Secret Service reported the arrests of two people who attempted to get into the White House in separate incidents. The White House was locked down after each attempt.

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Michael Zehaf-Bibeau carries a rifle while running toward Parliament Hill on Oct. 22, 2014, in a still taken from video surveillance. The RCMP have since been placed in charge of security both inside and outside of the Parliament Hill buildings. (RCMP/Canadian Press)

Fence-jumpers and other intruders have been a chronic problem at the White House in recent years, and one person actually made it into the building last September. That incident led to the resignation of a senior security executive.

Late last month, the Senate and House of Commons each voted to turn over security inside the Parliament Buildings — now handled by a parliamentary force — to the RCMP, which currently patrols only the exterior unless called on for assistance. RCMP Commissioner Bob Paulson has said changeover plans are still "preliminary."

A database compiled by the Canadian Network for Research on Terrorism, Security and Society shows just six serious attacks on the Parliament Buildings before the Oct. 22 incident, the most recent in 1997 when a disturbed man was subdued inside the Centre Block.

The most serious attack occurred in 1966, when a man died in the premature explosion of a bomb he had planned to throw into the House of Commons chamber. Another 15 minor cases involved white powder mailed to addresses inside the Parliament Buildings in 2003.

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