Former RCMP officer Benjamin (Monty) Robinson has been convicted of perjury related to his testimony at a public inquiry into the Taser death of Polish immigrant Robert Dziekanski.

Robinson was charged along with three other officers for their testimony at hearings that examined what happened when Dziekanski was stunned with a Taser at Vancouver's airport and died in October 2007.

Dziekansi's mother, Zofia Cisowski, was at the courthouse today.

"I feel sad," she said, adding that she's still suffering from the loss of her son.

Zofia Cisowski, the mother of Robert Dziekanski, reacts to the conviction of Monty Robinson on a perjury charge. (Kirk Williams/CBC)

"I'm here because I need to have justice for my son Robert," Cisowski said. "I would like to see them in jail because they knew what they were doing."

Robinson is the second of the officers to be convicted of perjury.

Const. Kwesi Millington was convicted last month and is awaiting a sentencing hearing which is expected May 7.

Const. Bill Bentley was acquitted of the perjury charge in 2013, though the Crown is appealing the verdict. Const. Gerry Rundel's trial has finished and a verdict is expected April 30.

While each officer faced the same charge, Robinson's case had the most notoriety. The court found Robinson guilty on two of eight Crown allegations. The case was adjourned until April 2 when a date will be set for sentencing, said Neil MacKenzie , a spokesperson for B.C.'s Criminal Justice Branch.

Robinson was the senior officer on the scene at the airport in the early morning of Oct. 14, 2007.

He and the three other officers were summoned to Vancouver's airport after Dziekanski, who spoke no English, started throwing furniture in the international terminal. Within seconds of the officers' arrival, one of them stunned Dziekanski repeatedly with a Taser.

Former RCMP Cpl. Benjamin (Monty) Robinson leaves B.C. Supreme Court in New Westminster, in July 2012 after his sentencing hearing for an obstruction of justice conviction was adjourned. (Darryl Dyck/Canadian Press)

The Crown alleged the four officers colluded on a story to tell homicide investigators and then lied again at the public inquiry.

B.C. Supreme Court Judge Nathan Smith said the officers all made similar mistakes when their statements are compared with the video, notably their incorrect assertion that Dziekanski had to be wrestled to the ground.

Smith said Robinson had a motive to lie and must have known what he told homicide investigators was incorrect.

"I simply do not believe that a police officer of his experience could make such a crucial mistake in these circumstances," Smith said as Robinson listened from the prisoner's dock.

Motive to exaggerate

"I agree with the Crown that he had a direct motive to exaggerate the threat posed by Mr. Dziekanski and to justify the response to that threat."

Smith said it's clear the officers talked about what happened before speaking to homicide investigators, which Robinson denied while on the stand at the inquiry.

Much of the Crown's case was circumstantial.

Prosecutors argued the officers' statements and notes all contained similar errors when compared with an amateur video of the confrontation, proving they worked together.

The Crown did not produce any evidence that the officers actually collaborated on the night of Dziekanski's death, such as a witness who might have seen them huddled together at the airport.

The Crown further alleged the officers met in the Vancouver area in the days or weeks before testifying at the inquiry in early 2009 to plan their testimony.

A witness, whose ex-husband is Bentley's cousin, told the court the officers met at her home, but the defence presented telephone records, credit card receipts and other evidence to cast doubt on her testimony.

The Crown has not explained how the public should reconcile the differing verdicts, especially since the prosecutors' theory was that all four officers worked together to tell the same lies.

Convicted of obstruction of justice

Robinson, who is in his mid-40s, left the RCMP in 2012, after being convicted of obstruction of justice in an unrelated case involving a fatal vehicle accident in 2008.

Robinson was behind the wheel in October 2008 when his vehicle struck and killed a 21-year-old motorcyclist in Delta, south of Vancouver.

At trial, he said that immediately after the crash he went home and drank two shots of vodka to "calm his nerves."

A judge concluded Robinson had used his RCMP training in an attempt to fend off accusations of impaired driving. He was given a conditional sentence of 12 months.

Around the time of Robinson's obstruction conviction, the RCMP's top officer in B.C., Deputy Commissioner Craig Callens, held up the case as an example of the challenges facing the force when it wants to deal with problem officers.

Callens said he was "outraged" with Robinson's conviction and said it demonstrated the need to change the law that governs how Mounties can be disciplined or fired.