VANCOUVER -- Chris Mohan and Ed Schellenberg spent the final moments of their lives with hoods covering their heads, waiting for gunfire in artificial darkness.

They were in a 15th-floor condo unit in a suburban area near Vancouver, surrounded by members of the region's violent gang underworld, with whom they had no connection other than geography and terrible timing.

Mohan, a 22-year-old student, lived across the hall with his parents. Schellenberg, a 55-year-old repairman, had spent the week servicing the gas fireplaces in the building, located in Surrey, B.C.

But somehow -- that part of the story has yet to be told -- the pair were corralled into what prosecutors allege was a "stash house" along with four other men, who, unlike Mohan and Schellenberg, were connected with gangs and drugs.

The men were divided into two groups, with Mohan in one and Schellenberg in the other.

Nineteen bullets later, all six were dead.

The Crown began its long-anticipated case Monday against three alleged gang members who face murder and conspiracy charges in the Oct. 19, 2007 killings and outlined for the first time publicly what prosecutors believe happened.

When the bullet-ridden bodies of the six men were discovered inside the unit, they became a powerful symbol of the carnage wrought by drug-fuelled gang violence that continued for another two years.

Matthew Johnston, Cory Haevischer and Quang Vinh Thang (Michael) Le are now on trial in a case that is expected to last an entire year. A co-accused has already pleaded guilty and another, notorious alleged gang leader Jamie Bacon, is scheduled for trial next year.

Johnston and Haevischer are accused of being directly involved in the killing, while Le and Bacon are accused of being part of the conspiracy.

Crown counsel Mark Levitz said the three men currently on trial were associated with the Red Scorpions gang, led by Le and Bacon.

The plan that day was to execute a rival drug trafficker named Corey Lal, said Levitz. Earlier, Bacon and Le attempted to extort $100,000 from Lal, but he missed a deadline to pay, said Levitz.

"The Crown anticipates establishing that the accused and their fellow conspirators ... killed and conspired to kill Corey Lal, and they did so to advance their drug trafficking business by eliminating a drug rival operating in the same area and also to send a message to the drug world that they were not to be defied," said Levitz.

"The accused Johnston and Haevischer, together with (a third co-conspirator), murdered (the other five victims) to ensure there would be no witnesses to the crime."

Johnston, Haevischer and another person, who can't be named because of a publication ban, were tasked with taking out Lal, Levitz said. The plan was to target Lal at a condo unit in Balmoral Tower, which he used as a "stash house" for drugs and money, said Levitz.

In the hours before the killing, Johnston met a Red Scorpions associate at Lal's apartment complex, said Levitz. The unnamed associate lived in the same building and provided Johnston with the electronic fob needed to get inside, the Crown said.

Johnston and the third person involved in the killing then met at a nearby Korean restaurant, where the third man was handed a handgun that would later be used in the killing, said Levitz. From there, they went to pick up Haevischer at his apartment, a short drive away from the Balmoral, said Levitz.

Witnesses saw a vehicle that matched the description of Haevischer's BMW drive into the Balmoral's underground parkade, where they used the fob to gain entrance to the building, said Levitz.

Once inside Lal's unit, Levitz said the trio found four people with ties to the drug world: Lal, Lal's brother Michael, Edward Narong and Ryan Bartolomeo.

The Crown has yet to outline precisely how Mohan and Schellenberg were dragged into the plot, though at some point they found themselves inside as well.

The Lal brothers, Narong, Bartolomeo, Mohan and Schellenberg were divided into two groups of three, said Levitz. Their heads were covered and they were each shot multiple times, with most of the bullets targeting their heads and necks, said Levitz.

Shortly after, a witness saw a BMW speed out of the building's parkade, said Levitz.

Schellenberg had been scheduled to service the condo unit where the killings took place that afternoon, the court heard.

Building manager Norman Carothers became concerned when Schellenberg did not report in as expected and failed to show up at the apartment he was scheduled to service next.

After several failed attempts to locate Schellenberg, Carothers decided to enter the apartment, he told the court.

"I open the door and I come across this scene, I see six people on the floor," said Carothers.

Initially, Carothers thought there had been a gas leak.

"I grabbed who I thought was Ed by the feet, and I was pulling them out," said Carothers, who choked up as he recalled what he saw.

"I pulled him no more than a couple of feet. I'm saying, 'Ed, Ed,' and I look around and I see this scene. So I backed up out of the apartment without touching anything and I got on the walkie-talkie and told my wife to phone 911, call everybody out, the fire department, police, ambulance, because something has happened here. Everyone is on the floor. There was blood."

The court was shown two photographs of the victims, still lying on the apartment floor. Michael Lal was found lying on his back, while the other five were face-down.

Family members of the victims were in court for the opening of the trial, including Mohan's mother, Eileen, who later said she quickly turned away after catching a glance of the photograph of her son's body.

"I looked once and then I looked away," she said outside court, struggling at times to speak through tears.

"I want to remember my son the way he was, not in this state, in blood and amongst strangers he never knew and people who he never should have died with. The most difficult part of it was this."

The trial opened in a crowded courtroom, where dozens of witnesses sat after passing through airport-style security. The trial is taking place in a secure courtroom that was also used for the Air India bombing trial.

The case is expected to last a year, as a judge hears from a long list of witnesses, including gang members, undercover police officers and a police agent. The trial will also see video surveillance and cellphone records that document the movements of the accused before and after the murders, as well as wiretap evidence, said Levitz.

Levitz said the court will hear that Johnston, Haevischer and Le each admitted involvement in the killings.

He said Johnston and Le admitted involvement during an undercover operation in 2008, though he said the exact details of the alleged admission will have to wait until later in the trial. Levitz did not explain the circumstances of Haevischer's apparent admission, which he said occurred shortly after the killings and also involved Johnston.

The murders happened in the early days of what would grow into a full-scale gang war that endured for another two years. In the months following the murders, 10 people were killed in shootings. In one particularly deadly month in early 2009, there were 31 shootings, 12 of them fatal.

Jamie Bacon has been charged with first-degree murder in the death of Corey Lal, and -- with Haevischer, Johnston, and Le -- conspiracy to commit murder in Lal's death.

Haevischer and Johnston each face six counts of first-degree murder and one count of conspiracy. Le faces one count of first-degree murder and one count of conspiracy.

The three men pleaded not guilty to the charges as the trial started Monday.