Aaron Guilbault (GILL'-boh) is charged with second-degree murder.
Timothy Guilbaut, a former Red Deer city councillor, was found beaten to death in a home near Innisfail in November 2012.
The defence said that there is enough evidence to prove that Guilbault cannot be held criminally responsible due to mental illness.
The Crown argued that psychotic episodes or schizophrenia do not necessarily excuse an accused from responsibility in a crime.
The Court of Queen's Bench judge who heard the case is expected to hand down her decision on Nov. 20.
Guilbault underwent a psychiatric assessment after his arrest and was found fit to stand trial.
(CHUB, The Canadian Press)