MONTREAL - The Crown is describing it as a Hells Angels conspiracy hatched to create anarchy within Quebec's justice system while ensuring that biker gang underlings shied away from becoming police informants.

More than 11 years after the brazen slaying of prison guard Pierre Rondeau and the attempted murder of his partner Robert Corriveau, the first-degree murder trial of Paul (Fon Fon) Fontaine began in Montreal on Monday.

Rondeau's death is one of two that led to the conviction of Hells kingpin Maurice (Mom) Boucher, who is serving a life sentence after being found guilty of ordering the killings.

Corriveau, now 62, told jurors on Monday what happened the morning of Sept. 8, 1997, when he and Rondeau were ambushed.

Corriveau narrowly escaped what the retired prison guard described as certain death.

"It's difficult to describe, but I was prepared to die," he told the five-man, seven-woman jury, adding he has replayed the scenario so often in his mind.

Rondeau and Corriveau were assigned to ferry prisoners to and from the Riviere-des-Prairies detention centre and the Montreal courthouse and they set off from the courthouse on the fateful day with Rondeau behind the wheel.

Engaged in idle chit-chat, Corriveau caught the glimpse of a gunman dressed in dark colours while stopped at a railway crossing, his weapon trained right at them.

"I looked up toward the front, I don't know why," said Corriveau, who was seated in the passenger seat of the bus.

"What I saw was a gunman aimed and ready to shoot, pointing back at me,"

What followed was a volley of bullets that hit Rondeau with deadly precision as Corriveau dropped to the ground.

"There was silence. My thoughts felt heavy, I didn't know what was going on," Corriveau said, occasionally glaring at an emotionless Fontaine in the prisoner's box.

"After a few seconds I went to check on my partner ... he was hit and there was blood everywhere, there was nothing I could do."

Some of the Montreal police officers who first arrived at the scene also testified Monday, describing to varying degrees a bullet-riddled prison bus with Rondeau near death inside, Corriveau in shock and bullet casings littering the ground.

Crown prosecutor Randall Richmond told jurors he intends to show that Fontaine, a top Hells lieutenant in its elite Nomads chapter, was part of a conspiracy involving Boucher, Andre (Toots) Tousignant and Stephane (Godasse) Gagne to murder prison guards.

Richmond said the gang's motive was to destabilize the Quebec justice system and eradicate the problem of police informants within the gang.

Under Boucher's orders, the Hells also planned to kill police officers, Crown prosecutors and judges, Richmond said. Boucher surmised that low-level bikers would never be able to become informants because the Crown would be unlikely to deal with people who killed correctional employees.

Richmond also said the more than 140 scheduled witnesses will include Gagne, a biker hitman who turned informant. Richmond emphasized that Gagne's testimony will be key as, according to the Crown, he was with Fontaine the morning of the shootings.

Fontaine disappeared after the shootings and only resurfaced in 2004 when he was found living in Quebec City under an alias, Jean Boyer.

Tousignant was assassinated and his burned corpse was found in 1998 in a field near Bromont, Que. Fontaine was thought to have met a similar end until his surprise arrest years later.

Thanks to Gagne's testimony, Boucher was sentenced to life in prison in 2002 after being convicted of ordering Rondeau's death as well as that of another guard, Diane Lavigne.

Gagne remains behind bars under protection.

Fontaine's trial is taking place under heightened security and is scheduled to last until the end of January.