A 45-year-old firefighter from St. Bruno has been found guilty of criminal negligence causing death of his sex partner during an S&M session in February 2008.

During his trial, Patrick Deschatelets had stuck to his story that his partner was a consenting partner, and said the victim was okay with him going out to buy pasta, leaving her alone for 20 minutes, wearing a metal collar, chained to the ceiling in his basement.

The woman, whose identity is protected under a publication ban, suffocated to death.

Judge Claude Provost came down hard on Deschatelets, saying a reasonable person in this situation should foresee the risks to life and security, and that in such dangerous and violent sex games, Deschatelets had the duty to ensure the woman's safety.

Sentencing arguments are set for early April. The defence may appeal.