A disciplinary hearing has found a high-ranking Toronto police officer who ordered two mass arrests of protesters at the G20 in 2010 guilty of discreditable conduct and unnecessary exercise of authority.

Retired Ontario Superior Court judge John Hamilton handed down his ruling in the case of Supt. Mark Fenton on Tuesday morning at police headquarters.

Fenton, with Toronto Police Services, was found guilty of three of the five charges against him.

While delivering his verdict, Hamilton said Fenton is committed to serving the public, but lacked understanding of the public's right to protest and had no responsible grounds to order the arrests.

Fenton was a major incident commander in charge of the downtown core on June 26 and 27, 2010, when police officers used the so-called kettling tactic to surround and arrest hundreds of protesters, most of whom were never charged.

Fenton's police disciplinary hearing was originally slated to begin in 2012, but was delayed for over two years before it started last November. The officer had pleaded not guilty to all Police Services Act charges against him.

Supt. Mark Fenton, who ordered two mass arrests of protesters at the G20 in 2010, was found guilty of discreditable conduct. (Pam Davies/CBC) Fenton, the most senior officer to be charged in connection with the G20, will be sentenced on Dec. 21. He could be reprimanded or dismissed from the police force.

The veteran officer has remained on the job throughout the proceedings. It's unclear whether he will appeal the decision.

Two mass arrests lead to charges

The charges stem from two mass arrests in the downtown core. The first, on June 26, was ordered hours after a small group of vandals smashed windows and set police cruisers ablaze. Fenton ordered officers to box in protesters in front of a Novotel hotel.

More than 260 people were arrested and taken to a makeshift prisoner processing centre, which came under severe criticism for its deplorable conditions.

Paul Cavalluzzo, who represents complainants from the Novotel incident, said Tuesday he is satisfied that charges have been laid against Fenton but added that "there are other people, higher than Supt. Fenton, who should be held to account for what happened."

Prime Minister Stephen Harper, he said, is one of those people.

"He called for the G20 to happen in downtown Toronto. It clearly shouldn't have been," Cavalluzzo said. "It was called for political reasons, and as a result of that over 1100 peaceful Canadians protesting were arrested unlawfully and detained for 24 hours in Third World country conditions.

"He should be held to account as others below him," Cavalluzzo said.

Two charges Fenton was not found guilty of relate to the prisoner processing centre. Though Hamilton did not argue with the conditions at the centre, he said there was an officer of equal standing in charge of the detention centre so Fenton was not responsible for what happened there.

Those two charges that were dismissed were mass unlawful arrest and discreditable conduct.

The second incident occurred the next day when, six minutes after coming on shift, Fenton ordered police to keep scores of people standing for hours at the Queen Street East and Spadina Avenue intersection despite a severe thunderstorm that left them drenched.

Shervin Akhavi was one of the people who was kettled at that intersection.

"Obviously, I'm very happy that the police commander who doesn't understand his role has been found guilty," Akhavi said. "I was protesting peacefully (when) suddenly we found ourselves kettled and were held there in the rain. Kenton punished us for exercising our rights and freedoms."

Prosecution lawyer Brendan van Niejenhuis told Fenton's disciplinary hearing.that "the order made in each case was, the evidence will show, indiscriminate."

Fenton issued an apology Tuesday afternoon via a statement from his lawyer, Peter Brauti.

"He would like to personally apologize to all those innocent parties that were negatively affected," Brauti said.

"He had to make quick decisions and judgement calls to protect the city. He deeply regrets that some of those decisions led to the arrest of people who were not involved in the violence and that some people were held in the rain for hours."

Brauti said he and Fenton are disappointed with the charges but respect the ruling and process.

More than 1,000 people were detained over the summit weekend in what is considered the largest mass arrest in Canada's peacetime history.