A Blenheim man has been found not criminally responsible for the death of his wife.

79-year-old Walter Ardis was charged with first degree murder after his wife, 73-year-old Margaret Ardis, was found dead inside their home in March 2016.

Emergency crews made the discovery responding to a fire call.

On Monday, an Ontario Superior Court judge in Chatham ruled he was convinced Walter Ardis killed his wife and set their home on fire.

However, Justice Bruce Thomas ruled Ardis wasn't criminally responsible because of a mental disorder following a psychiatric assessment.

Ardis has returned to the Southwest Centre for Forensic Mental Health Care in St. Thomas where it's expected a hearing will decide on Ardis' future within the next 45 days.