The panel convicted John Nuttall and Amanda Korody of conspiracy to commit murder and possession of an explosive substance on behalf of a terrorist group.
In an unusual twist, the conviction won't be entered until next week, after the defence has a chance to argue that police entrapped the couple into the plot during an elaborate sting operation.
As the verdict was read out, Nuttall made a heart shape with his fingers directed at Korody.
The jury began deliberating behind closed doors on Sunday morning after hearing more than four months of testimony.
The couple was arrested on July 1, 2013, the day they were accused of planted three pressure-cooker bombs on the grounds of the legislature. The police had ensured the bombs were inert.
Covert recordings were taken of Nuttall and Korody at home, during meetings in various hotel rooms and while driving around with undercover officers. One video appeared to depict the two hiding their faces with scarves and filming a jihadist video they planned to release after their attack.
The Crown alleged the couple used what they believed were authentic al-Qaida connections to secure several kilograms of what RCMP officers have testified were fake explosives to arm a trio of pressure-cooker bombs brimming with deadly metal shrapnel.
The court watched covert video footage showing Nuttall and Korody planting the bombs beneath decorative bushes flanking the B.C. legislature early Canada Day morning.
Recordings played in court showed the pair saying they believed killing women and children was acceptable so long as they weren't explicitly targeted in the attack but rather died as collateral damage.
Testimony from an explosives expert revealed the range of the bombs, had they been real, would have reached beyond the border of the legislature's front lawn and far into the city's picturesque Inner Harbour.
At numerous points in the surveillance recordings Nuttall could be heard describing the Boston Marathon bombing as inspirational but also amateurish, and that he hoped his attack would kill hundreds.
In its cross-examination of the Crown's witnesses, the defence offered an alternative interpretation of events, highlighting what they characterized as the heavy-handed role played by the police in guiding Nuttall and Korody throughout the undercover investigation.
Defence lawyers zeroed in on instances where undercover officers encouraged Nuttall and Korody to follow a quicker timeline, or to opt for a more realistic terrorist plot and to abandon plans recordings revealed the couple had previously proposed, such as hijacking a nuclear submarine or taking a commuter train hostage.
Nuttall's lawyer Marilyn Sandford accused the key undercover officer involved in the RCMP sting of using the threat of disappointing Allah to frighten her client into hatching a viable plot for jihad.
She also blamed police for removing every conceivable obstacle hindering Nuttall's violent ambitions, from giving him money, promising him employment and even guaranteeing his cat would be taken to a good, Muslim home.
Besides video and audio surveillance, evidence presented to the jury included a look into nail-lined pressure cookers, as well as a tour through Nuttall's laptop computer, which contained saved copies of al-Qaida's online magazine Inspire and a do-it-yourself guide on building and detonating explosives.
Nuttall and Korody initially faced four charges, but B.C. Supreme Court Justice Catherine Bruce entered a not-guilty plea in mid-May on one of the four — knowingly facilitating a terrorist activity — citing unspecified legal reasons.
Neither of the accused testified in court.
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