VANCOUVER -- One of the four Mounties who confronted Robert Dziekanski the night the Polish immigrant was stunned with a Taser, leaving him to die on the floor of the Vancouver airport, says the fatal confrontation was "the most traumatic" thing that had ever happened to him.

Const. Bill Bentley broke down in tears Monday as he described what happened in the hours after Dziekanski died -- part of a pre-trial hearing to determine what evidence should be admitted at his trial for perjury. He is accused of lying at a public inquiry.

Bentley said he was busy taking statements from witnesses when his superior -- another one of the officers facing perjury charges -- told him Dziekanski had died. Shortly after, he was told to leave the airport and return to the RCMP's detachment near the airport to wait for homicide investigators.

"I was a mess, I was just really upset about the whole incident," said Bentley.

"I describe it as basically the most traumatic thing in my life."

Shortly after a series of questions about his emotional state, Bentley's lawyer changed the topic, but Bentley choked up as tears ran down his face. The emotional breakdown prompted the judge to stand the hearing down while Bentley regained his composure.

Bentley and three other officers responded to 911 calls in the early morning of Oct. 14, 2007, after Dziekanski, who had been in the airport for nearly 10 hours and spoke no English, started throwing furniture.

Within seconds of arriving, one of the officers stunned Dziekanski several times with a Taser. Dziekanski died shortly after.

They were charged with perjury in May 2011 over allegations they lied at a public inquiry into the case. Bentley is the first to stand trial, and none of the allegations -- against him or any of the other officers -- have been proven in court.

Bentley is accused of lying six times during his testimony at the public inquiry, primarily when he attempted to explain apparent discrepancies between his police notes and an amateur video of the incident. The indictment read out on Monday also alleges Bentley lied when he said he couldn't remember what he said to the other three officers about the incident.

The trial was scheduled to start Monday, but the defence and the Crown each made applications regarding the admissibility of evidence.

Specifically, the judge has been asked to decide whether a statement Bentley made to homicide investigators should be admitted as evidence. The hearings this week will also determine if statements from the other three officers should be allowed in.

Bentley was the second witness, and his testimony was limited to the circumstances surrounding the statement he made to the police.

He told the court he had interviewed several witnesses when Cpl. Benjamin Robinson, who is also charged with perjury, told him Dziekanski had died.

Shortly after, Bentley was told to leave the airport and head to the RCMP's airport detachment, a short drive away, to give statements to homicide investigators.

The court heard from a staff relations representative, who fulfills the same role as a union representative, who told the officers they would be asked to provide a "duty to account" statement. "Duty to account" was a vague term to describe a practice of ensuring officers provide a detailed account when they are involved in such a incident, the court heard.

One of the homicide investigators involved in the case, Staff Sgt. David Attew, told the court he believed RCMP officers were obliged to provide a statement under their duty to account and they would likely face discipline if they didn't comply.

The court heard Bentley was not told his statement could be used as evidence -- known as a charter warning -- and was not given the chance to speak with a lawyer.

Attew said the officers weren't given charter warnings because, at the time, investigators did not believe there was any evidence of a crime.

The court also heard that another homicide investigator told the officers, "You guys aren't suspects or anything like that," which the Crown suggested was more proof the officers weren't treated as suspects.

Under questioning from the Crown, Bentley said he was never told he was under investigation for a crime. Crown counsel Scott Fenton suggested Bentley had nothing to worry about.

"You in your own mind you did not think you had done anything wrong that night?" asked Fenton

"No, I didn't think I did anything wrong," replied Bentley.

The pre-trial hearings on evidence are expected to last the entire week. The trial is scheduled to last up to three weeks.

Monday's hearing began with Bentley pleading not guilty to the perjury charge.

The three other officers -- Const. Kwesi Millington, Const. Gerry Rundell and former corporal Benjamin Robinson -- are scheduled for separate trials in November of this year and February 2014.