The 83-year-old accused was charged in 2022 with a historical murder from 1975.
A fitness hearing was held to determine if his cognitive decline rendered him unfit to stand trial.
While early assessments suggested potential malingering, subsequent psychiatric evaluations confirmed a diagnosis of Moderate Neurocognitive Disorder (dementia).
The court accepted the joint submission of the Crown and defence, finding that the accused's dementia severely compromised his ability to sustain attention, follow proceedings, and instruct counsel.
The accused was found unfit to stand trial and ordered transferred to a psychiatric hospital.