Royal Canadian Mounted Police Commissioner Giuliano Zaccardelli told the Commons Public Safety committee that he accepts the report from the Arar inquiry. (Tom Hanson/ Canadian Press)

RCMP Commissioner Giuliano Zaccardelli has been a much-maligned public figure ever since the revelation that the Mounties falsely identified Maher Arar as an al-Qaeda terrorist link. Zaccardelli resigned his post one day after testifying before a Commons committee for a second time, in December 2006, saying the timeline he gave in his first appearance that September was inaccurate.

On Sept. 28, 2006, the top Mountie told the committee he got involved in the case before Arar had been detained, but in December, he insisted that he learned a lot more about RCMP involvement after a public inquiry report by Justice Dennis O'Connor was released this fall.

During his first appearance in September, Zaccardelli apologized to Arar and said the lessons learned had been painful but valuable.

Zaccardelli is no stranger to the hot seat. Here are the key events in Zaccardelli's six-year career as RCMP commissioner:

Dec. 6, 2006:

Zaccardelli submits his resignation to Prime Minister Stephen Harper. Harper accepts the resignation, effective Dec. 15.

Dec. 5, 2006:

Zaccardelli appears before the Commons committee on public safety and national security for a second time. He says he made a mistake when he gave inaccurate testimony to the committee in September about the Maher Arar case.

"I believe some aspects of my prior testimony could have been more precise and more clearly stated. A number of misconceptions have resulted," he says.

Zaccardelli says he first learned that the Mounties had passed erroneous information about Arar on to U.S authorities after a public inquiry report was released by Justice Dennis O'Connor in the fall of 2006. In September that year, Zaccardelli told a parliamentary committee he had learned of the RCMP's mistake shortly after Arar's deportation to Syria in 2002.

Zaccardelli tells the committee his mistake should not lead to his resignation.

Minister of Public Safety Stockwell Day says he "had no knowledge" the commissioner would change his story.

Prime Minister Stephen Harper expresses "concern" over Zaccardelli's conflicting testimony, but says he should not be fired "without due process."

Dec. 4, 2006:

In a speech at the Canadian Club in Ottawa, RCMP Commissioner Giuliano Zaccardelli says he first learned that the Mounties had passed erroneous information about Maher Arar on to U.S authorities in the fall of 2006. In September that year, Zaccardelli told a parliamentary committee that he learned of the RCMP's mistake shortly after Arar's deportation to Syria in 2002.

Sept. 28, 2006:

For the first time since a damning report was released, Zaccardelli speaks before the House of Commons Security Committee and finally apologizes for RCMP "errors" that resulted in the wrongful arrest, deportation and torture of Maher Arar in a Syrian jail in September 2002.

Calling the ordeal that Arar went through a "nightmare," he also praises the Arar family for maintaining their dignity and maintains he will not resign as commissioner because of the RCMP blunder.

Sept. 18, 2006:

Justice Dennis O'Connor completely exonerates Arar of any wrongdoing and puts Zaccardelli in the hot seat, after tabling a damaging report that flowed from a public inquiry into the Arar affair. The report slams the RCMP for mishandling the case and calls for Ottawa to pay damages and apologize.

In the report, O'Connor says the Mounties passed erroneous intelligence to American officials that falsely linked Arar with terrorist activities, which led to his arrest, deportation and torture in a Syrian prison.

Zaccardelli, out of the country on business, does not comment on the report or demands from critics that he resign as commissioner. He remains silent on the report's findings while the Liberals accuse the government of "muzzle mania."

March 2, 2005:

James Roszko, a convicted pedophile known to police for a history of gun possession and violent crime, guns down four young RCMP officers in Alberta before killing himself.

The worst massacre of RCMP officers in the force's history prompts immediate questions about how prepared the officers were in responding to what started as a routine call to repossess a truck.

Zaccardelli faces intense scrutiny as reports surface that police knew that Roszko monitored police radio scanners and was not under surveillance, despite his criminal past and possession of firearms.

"An ordinary and manageable police investigation took a random and unexpected turn to the unmanageable and tragic," Zaccardelli said at the time.

Sept. 8, 2004:

Auditor General Sheila Fraser reveals during a judicial inquiry into the federal sponsorship scandal that the RCMP spent almost $18,000 in sponsorship money to buy souvenir corkscrews. Fraser says the RCMP bought the corkscrews for $8,000, then paid another $10,000 for the same items.

Justice John Gomery, the head of the inquiry, is critical of Zaccardelli — who calls Fraser's findings "minor accounting lapses" — and takes the RCMP commissioner to task for trivializing the finding.

April 22, 2004:

In a damning report, Auditor General Sheila Fraser blasts the RCMP about a decision to spend $107,000 of funds from the sponsorship program for expenses, including buying horses and trailers.

Zaccardelli testifies before a parliamentary inquiry into the misuse of federal taxpayers' money, admitting that the force made serious mistakes in handling the sponsorship money and that the purchases were made after former public servant Chuck Guité gave the go-ahead.

Nov. 13, 2003:

The Commission for Public Complaints Against the RCMP concludes the Mounties used "excessive and unjustified force" to disperse protesters at the 2001 Summit of the Americas in Quebec.

Sept. 7, 2001:

Following the release of the APEC inquiry report in August, Zaccardelli concedes the Mounties botched security planning for the 1997 Asia-Pacific Economic Co-operation summit, leading to the pepper-spraying of crowds of protesters and 42 arrests in Vancouver.

"In general, I agree and accept that errors were made by the RCMP," he tells a news conference, but also sidesteps the report's finding that RCMP officers violated rights of some demonstrators.

Aug. 22, 2001:

Zaccardelli draws scorching criticism after he urges for legislation that would give police the freedom to break the law while working undercover.

Critics fear the new legislation could lead to an abuse of power by authorities, but Zaccardelli argues the strategy, which would grant immunity to officers committing lesser crimes, could help police deal with organized crime in Canada.

Aug. 14, 2001:

Zaccardelli says a criminal investigation of Ontario premier Mike Harris is unwarranted in connection with the police shooting of native activist Dudley George. An unarmed George was shot and killed by police during a 1995 confrontation with about three dozen natives protesting what they said was the desecration of their ancestors' burial grounds.

Ontario NDP leader Howard Hampton wrote Zaccardelli, saying documents filed in a wrongful-death lawsuit by the George family have revealed "links between the government and the premier's office and the events that led to Mr. George's killing."

Sept. 2, 2000:

Zaccardelli is appointed the 20th commissioner of the RCMP.