Former friends and colleagues of Michael Sona testified on Monday as the Crown kicked off its case against the 25-year-old accused of trying to keep some Guelph, Ont., residents from voting in the 2011 federal election.

Sona faces the single charge of wilfully preventing or endeavouring to prevent a voter from casting a ballot, in the so-called robocalls case related to automated calls made during the lead-up to the May 2, 2011, election. ​

Sona's former roommate, Chris Crawford, said he overheard the former Conservative staffer talking about voter suppression tactics and advised him it wouldn't be smart to use them, the witness told a trial in Guelph, Ont.

Another witness from the 2011 Conservative campaign team in Guelph, John White, said Sona was a highly enthusiastic campaign worker and "gung-ho."

White was in charge of get-out-the vote efforts, or making sure supporters turned up at polling stations. He also pulled a number of non-supporter lists from the Conservatives' database. Elections Canada believes it was a list from the Conservative Party database that was used to make the misleading robocalls.

Crawford, who in 2009 was a Conservative Party intern with Sona and who went on to work with Sona on the campaign of Conservative candidate Marty Burke in Guelph, testified he heard Sona talking to campaign manager Ken Morgan late one night.

Crawford said Sona and Morgan were close, and that he remembers Sona talking to Morgan ‎about voter suppression tactics such as making late-night phone calls claiming to be on behalf of an opposing party, or to direct them to the wrong polling station.

Voter suppression not 'smart to do,' trial told

Crawford said he didn't think much of it at the time.

"In campaigns you often hear yammering on about different things and you don't think these things will actually happen. You give people the benefit of the doubt," Crawford said.

Crawford had to reread two parts of his statement to an Elections Canada investigator to refresh his memory. He made the statement March 6, 2012, 10 months after the mysterious misleading robocall was made and after an initial flood of media reports about the investigation.

Crawford said he later told Sona that voter suppression is "something I wouldn't think was smart to do." He said Sona didn't say much in response.

During the cross-examination, Sona's lawyer, Norm Boxall, asked whether Crawford recalled Sona saying he agreed with or approved of voter suppression tactics. Crawford said he didn't remember Sona saying anything like that, and agreed with Boxall that there was no suggestion that Sona or anyone else on the campaign would use the tactics.

"No, no," Crawford said.

Crawford agreed that many Canadian Conservatives look to the U.S. for strategies. Crawford himself has gone to the Conservative Political Action Conference, he confirmed.

Untraceable calls

Sona and Crawford lived together when both were Conservative Party interns in 2009.

Crawford was in charge of canvassing in Guelph for the Conservatives' 2011 campaign.

Boxall zeroed in on the time when Sona's name hit the news as a possible perpetrator, which happened before Crawford went to the party to say he wanted to talk to Elections Canada. He approached then director of communications Fred Delorey, who referred him to Conservative Party lawyer Arthur Hamilton.

Boxall asked Crawford about a promotion he got two months after speaking to Elections Canada. Crawford said it meant a $15,000 raise.

Another Conservative Party staffer, Matthew McBain, who now works for a cabinet minister, described a conversation he had with Sona about making untraceable phone calls.

McBain worked in opposition research at Conservative Party headquarters in Ottawa, which White described as a job where staffers do things others might not want to do.

White said he referred Sona to McBain after Sona asked him about making untraceable calls.

McBain said he advised him to stay away from "stunts."

'Commonplace' conversations

White said the conversation wasn't unusual and agreed it didn't raise any alarm bells.

"Those sorts of conversations are commonplace so I can't say that they didn't happen ... conversations about various nefarious activities that could happen to you or would be fun to do to someone else. But I've never really taken them very seriously," White said.

He said he doesn't recall the conversation being about poll-moving calls.

"I think I would have remembered that," he told the court.

The other witnesses for the Crown include Sona's colleagues from that campaign and from Parliament Hill. The prosecutor said they're expected to say that Sona bragged about the misleading robocalls.

The witnesses will also include:

Matt Meier, who owns RackNine , an automated calling service used to make the misleading calls.

RackNine Chris Rougier , who was in charge of voter relations at the Conservative Party.

The most important witness in the Crown's case may be Andrew Prescott, the campaign's deputy and a friend of Sona's. Prescott signed an immunity agreement to protect him from whatever testimony he provides.

Prescott handled IT issues for the campaign and was the campaign's main contact with RackNine, the Edmonton-based company behind the services used to make the automated calls.

He is expected to testify Tuesday or Wednesday, followed by four witnesses who worked for the Conservative Party or for Conservative MPs on Parliament Hill.

The trial is to last eight days.

Sona has maintained innocence

Sona has always said he had nothing to do with the calls, but faces up to five years in prison if convicted of the single charge.

Sona, 22 at the time of the campaign, was the director of communications for Burke.

Burke's campaign manager, Ken Morgan, moved to Kuwait in the months after the election and isn't expected to be back in Guelph to testify.

While hundreds of people outside Guelph also complained about misleading or harassing robocalls, a report by Elections Canada later found that there wasn't enough evidence to support the idea of a co-ordinated campaign to suppress the vote across the country.