In May of 2009 Proulx was convicted of first-degree murder in the death of Nancy Michaud, a political aide to Quebec's then natural resources minister
She was sexually assaulted and killed in 2008, in Rivière-Ouelle, a small town in the Lower Saint-Lawrence region.
Michaud, a mother of two, worked as a riding assistant for late provincial politician Claude Béchard.
During his trial, Proulx confessed to killing Michaud. But his lawyers argued he should not be held criminally responsible for the crime, because he was incapable of understanding the consequences of his actions given his mental state, triggered by Effexor, an antidepressant medication he took for anxiety.
Proulx is currently serving a life sentence, with no chance of parole for the first 25 years.