Joshua Williams murder trial: 'Mr. Big' confession front-and-centre

The juryin the Joshua Williams murder trial began hearing testimony on Thursday, with a warning that theprosecution's case rests strongly on a "Mr. Big"confession obtained by undercover police officers.

Abiram Subramaniam, 23, is charged with second-degree murder in the stabbing death of 18-year old Williams in 2011.

He also faces a lesser charge of robbery against Clinton Sathiyaseelan, a friend of Williams,who was present when Williams was killed.

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Crown prosecutor Louis Bouthillier saidWilliams wastrying to break up a fight between Subramaniam and Sathiyaseelanon March 22,2011,when he was stabbed six times.

He said Williams had not met Subramaniam before that evening.

Prosecutor details night Williams was stabbed

Bouthillier told the court that the three young men had gone to the Plaza Cte-des-Neiges parking lot to hang out and "drink beer, smoke cigarettesand smoke some weed and then tragedy struck."

Subramaniam wasn't arrested until more than a year after Williams' death.

"Normally, this should have been an open-shut case:there was an eyewitness," Bouthillier told the court. But, he added, the witness "proved to be a reluctant participant."

Joshua was a bright kid, a good guy, a bit of a risk-taker but fearless.- JeannineJames, the victim's mother

Police investigators then decided to use a "Mr. Big" sting a police operation in whichundercover officers get into contact with the accused and try to recruit him for a fictitious criminal organization.

Bouthillier told the jury the accused admitted to stabbing Williams and explained why he did it to the undercover officers.

The confession was captured on videotape, which will be shown in court during the trial.

The defence is expected to challenge thatconfession.

The police practice is controversial, and critics say they can lead to false confessions.

Last year, the Supreme Court of Canada imposed more limits on how police obtain Mr. Big confessions, but it did not forbid the practice.

'He was my life': victim's mother

"Joshua was a bright kid, a good guy, a bit of a risk-taker but fearless," said Jeannine James, the victim's mother, outside court.

"I miss him a lot," she told CBC. Williams was her only child.

James said she has spent time over the last four-and-a-half years regretting that her son stepped in to break up the fight, but she has now come to accept it. She said she islooking forward to the end of the trial.

"I'll never detach from his memory, of course, but I need for this to be over," she said. "We just need to know that the system works and that justice works both ways."

The prosecution is expected to call 25 witnesses, including police investigators and experts on DNA and pathology.