03/14/2013 13:08 EDT | Updated 05/14/2013 05:12 EDT

Canada's top court denies Quebec killer new trial

The Supreme Court of Canada refused to hear the appeal of convicted murderer Francis Proulx in a ruling announced on the court's website early today.

In May of 2009, Proulx was convicted of first-degree murder in the death of Nancy Michaud, a mother of two and political aide to Quebec's then natural resources minister.

Proulx broke into Michaud's home in the Lower St. Lawrence area in 2008. He proceeded to shoot and kill Michaud after handcuffing her and sexually assaulting her.

25 years, no chance of parole

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.

The Quebec Court of Appeal thought otherwise and rejected Proulx's request for a new trial in 2012 — a ruling with which Canada's top court agreed today.

Proulx is currently serving a life sentence, with no chance of parole for the first 25 years.