A Newry Crown Court jury of nine men and three women, sitting in Armagh, acquitted 27-year-old hospital worker Gregory Lamont on the grounds he was insane at the time of the attacks.
In the early hours of 15 January last year, the jury heard that Lamont stabbed his 64-year old father John before turning on his 60-year-old mum Liz.
Lamont carried out the attacks as the couple made a desperate attempt to have him emergency sectioned at the Holywell hospital in Antrim.
Trial judge Mr Justice Weir said that what happened in the family home in Carnvale, off the Carniny Road, was a terrible tragedy - the consequences of which may never be repaired.
Mr Justice Weir said that, in the circumstances, a copy of the set of agreed facts should be sent to the Coroner's Office who may want to carry out a further investigation into the response and co-ordinated activates that evening of those at Holywell Hospital, the ambulance service and those on duty at Ballymena police station.
Prosecution QC Paul Ramsey and defence QC James Gallagher said there was no dispute as to the actual events of that tragic and heart-breaking night, nor was there any dispute as to Lamont's mental condition and that he was suffering an abnormality of mind.
The lawyers said that, as a result of the mental condition, Lamont did not appreciate that what he was doing was both morally and legally wrong and that the only proper and just verdict would be one of "not guilty".
Reading from a set of agreed facts, prosecutor Rose Anne McCormick, told the court of the strange and bizarre activities of Lamont who began putting out his clothing in bin bags, along with photos, books and even the television, while telling his mum that "Jesus was coming for him".
So concerned were the Lamonts, that they contacted their local Dalriada Urgent Call Surgery.
The doctor on call came to their home, and later, such was the seriousness of the situation, he even asked his driver to accompany him inside.
Ms McCormack revealed how over the next three hours, the doctor and his driver had phoned, not once, but several times, in a frantic effort to summon help from other local emergency services, as the situation deteriorated.
On one occasion when the doctor contacted Holywell Hospital, telling them he had an emergency admission, he was told he would have to wait to speak to the crisis response team.
They later suggested that Lamont's case should first be reviewed by a social worker.
When the ambulance service was contacted, the doctor and driver were advised they would have to wait up to two hours for assistance and were also asked to ensure the police were on hand.
When the police were present, they were told to ring again and an ambulance would be dispatched.
The police dispatcher reported that they were second on the list of calls awaiting a response.
The court also heard that the situation deteriorated so much that the doctor and his driver left the Lamont home in an effort to calm the situation, and that as Mrs Lamont was signing forms for her son's emergency admission, heard her husband John cry out "Aawh, naw", or something like that.
Ms McCormick said that as Mrs Lamont went to the kitchen she found her son with a "dagger" in his hand.
Her husband, standing by the sink, was bleeding from chest wounds, but neither he or their son spoke.
As she stepped forward, she recalled her son "lean toward her with the dagger in his right hand".
The lawyr added that he then "pushed it gently into the right side of her stomach" and that she "felt no pain".
When police finally arrived and approached the house, Lamont called to them: "Kill me, please kill me, the blood has been spoilt ... I am the devil, God help me".
Later when under arrest, Lamont confessed: "I'm guilty, I'm a murderer, I deserve to go to jail ... I did it, I'm guilty, I killed him".
Ms McCormick revealed that, when interviewed, Lamont told officers he could remember shouting but not the words, and that he had been "out of his mind".
He also admitted killing the family pet dog Tiny with his own Bowie knife, slitting its throat in the bathroom because, to him, "it had supernatural powers".
The lawyer added that Lamont insisted he had to kill his father in order to save him.
He claimed he "believed he was supposed to kill his father, in order to save him from Hell" and that afterwards he had "handed the knife to his father ... telling his own father, now you have to stab me, daddy".
Talking about the attack on his mother, Lamont said "he could not recall physically stabbing her, but indicated that she had forced her way between him and his father".
A consultant psychiatrist, Dr Christine Kennedy - one of three specialists to find him insane - said that Lamont told her that he believed he and his father were both in Hell and that he had "to make a blood sacrifice" in order for both of them to escape the clutches of the devil, although he also reportedly told her that he was the devil, or was possessed by the devil.
Lamont, currently residing at the Shannon Clinic at Knockbracken Healthcare Park in Belfast, was told by Mr Justice Weir that in light of the jury's verdict, one which he believed was the only verdict, he would make a hospital order "without restriction".
However, he added that he hoped that sometime in the future Lamont could regain his mental health.