Jean-Alix Miguel killed his wife during a violent argument in 1990 and pleaded guilty when he went to trial several months later.
But he didn't mention the crime when he applied to French-language school board to teach a trade course in 1998 and was asked if he had a criminal record.
Mr. Miguel's past came to light in a worker's compensation claim in 2004 and he was fired, but his union contested the dismissal and took it to arbitration.
An arbitrator ruled the Quebec charter of rights says there is no reason to fire a person if he has been convicted of a crime that's not linked to his job.
The school board appealed the ruling but it was upheld by Quebec Superior Court, and school board spokeswoman Louise Richard said today the school board is studying the case and will decide later whether to appeal the last ruling.