It was uncertainty of a novel situation that liberated some 1,200 potential jurors from the case of genocide charges against a Rwandan man living in Windsor.The jurors in the trial of Jacques Mungwarere had to be fluently bilingual and able to commit to a trial that could last for months.But as proceedings started, his lawyers requested a sudden change: A trial by judge alone. Prosecutor Luc Boucher agreed.And as the jury panel members laughed in relief, Judge Michel Charbonneau told them to go outside, enjoy the nice weather, and not come back.But behind the levity lay weeks of serious debate between prosecution and defence lawyers.This would have been the first genocide trial in Canada to be held in front of a jury.It’s up to the accused in most criminal trials to pick which system he wants, and defence lawyer Marc Nerenberg said he believes in juries, and Mungwarere was ready to have one. But in this case, there was uncertainty about the crucial instructions that the judge would give to the jury after all the evidence, when it was time for them to reach a verdict.No Canadian judge has ever instructed a jury about genocide."The issue ... has to do with what kind of unanimity the jury should have,” he told reporters. "There’s no Canadian law that determines that. In effect, the 12 jury members are entitled to arrive at a conclusion by different routes. In genocide, where there are many different crimes lumped together under a single charge, that becomes very complicated to determine."Do they have to decide that he did indeed committed a particular murder?Or is it good enough that each jury member thinks he committed some murder? They’re very different questions."It became risky to go in front of a jury” without knowing how it would be instructed, Nerenberg said. And since that question would only be settled near the end of the trial, there would be no chance to go back and pick a trial by judge alone."The uncertainty made it too risky.”The trial will still take months, lawyers for both sides agreed. But not having 12 jurors makes scheduling easier.Mungwarere, a former Windsor warehouse worker who entered Canada in 2001 and gained refugee status, was arrested after he was recognised by a fellow Rwandan living there.