Published Thursday, 13 December 2012
Coburn was given an indeterminate sentence. (© UTV)
35-year-old John Charles Coburn was handed the jail term as part of an indeterminate sentence.
However, Mr Justice Burgess warned that Coburn, who still hears his mother talking to him through his television, "may never be released".
Mr Justice Burgess explained that "for all intents and purposes it is equivalent to a life sentence", and that university educated Coburn's "release back into the community will be determined by the Parole Commissioners should they consider it safe to do so".
He had originally been charged with murdering his 53-year-old mother Lynn, but the charge was dropped when Coburn pleaded guilty to her "manslaughter on the grounds of diminished responsibility".
He had claimed "she is trying to kill us you know".
Antrim Crown Court had heard: "Death was due to decapitation and multiple stab wounds to the head, neck and chest."
The court also heard that Coburn's 32-year-old brother Andrew was also injured in the brutal savage attack at their mother's Rossburn Manor home in the quiet Co Antrim village of Connor near Kells on April 3 last year.
© UTV News