The Supreme Court of Canada has upheld the conspiracy conviction of a young man who helped two teenaged girls drown their
alcoholic mother in a bathtub.

A lower court convicted the man, whose name is protected under Canada's youth laws, of conspiracy to commit murder for his role in the 2003 death of his girlfriend's mother.

The court heard he suggested the sisters ply their mother with Tylenol 3 and agreed to help them come up with an alibi after the
murder.

Ontario's appeals court upheld the conspiracy to commit murder conviction, and today in a unanimous decision the Supreme Court did the same.

The high court was essentially asked to determine the stage at which someone becomes part of a conspiracy.

The justices opted for a narrow definition, whereby someone becomes part of a conspiracy if they help others in the act of
agreeing to commit a crime.