After 11 days of deliberations, a Quebec jury convicted an alleged leader of the Hells Angels, Maurice (Mom) Boucher, of all charges Sunday in the shooting deaths of two prison guards.

Boucher, 48, grinned as the verdict was read out. He was found guilty of attempted murder and two counts of first-degree murder.

The jury of eight men and four women concluded that Boucher had masterminded the killings of Diane Lavigne and Pierre Rondeau in 1997. The Crown accused him of ordering the killings in a plot to destabilize the justice system.

Maurice Boucher (File photo)

Boucher will get an automatic life sentence with no chance of parole for 25 years.

In a trial notable for its security measures, the jury was shielded from public view by an opaque screen. They received their final instructions from Superior Court Justice Pierre Beliveau on April 25.

• FROM MARCH 25, 2002: Alleged biker boss goes on trial for murder

He told the jurors they had to convict Boucher if they were convinced he had "incited, counselled or brought about" the guards' deaths. He also said they had to find him guilty of all three charges, or not guilty of all three charges.

This was Boucher's second trial on the same charges. He was acquitted in 1998, but the Crown successfully appealed that ruling last year – challenging the judge's instructions to the jury.

Lavigne was shot and killed while driving home from work in June 1997.

In September of the same year, Rondeau was killed when the prison bus he was driving was ambushed. Robert Corriveau was also working on that bus and escaped injury.

The Crown based its case on wiretaps, video surveillance, documents seized from Boucher when he was arrested and on the testimony of two former bikers.

The key witness for the prosecution was Stephane Gagne, who was involved in both murders. He testified he was ordered to carry out the killings by Boucher lieutenants Andre (Toots) Tousignant and Paul (Fon Fon) Fontaine and was later congratulated by Boucher himself.

Crown prosecutor France Charbonneau contended that the killings were intended to destabilize the justice system by making targets of guards, police, prosecutors and judges.

Charbonneau argued that Boucher wanted crimes committed by bikers that would be so serious that prosecutors wouldn't want to make deals to turn bikers into informants.

Defence lawyer Jacques Larochelle didn't call any witnesses and challenged the credibility of Gagne and Serge Boutin, the Crown's other key witness. He said the men were career criminals and habitual liars trying to get deals from justice officials.

He argued Gagne worked alone to kill the guards.

Charbonneau said she wasn't surprised by the verdict, and expected Larochelle to appeal.