A 35-year-old man, who killed his wife because he believed she was possessed, has been found not guilty of murder by reason of insanity.
Diego Costa Silva killed his wife Fabiole Campara de Campos Silva in November 2021.
Psychiatrists for the defence and the prosecution agreed that he was suffering from a cannabis-induced psychotic disorder at the time.
Mr Costa Silva sobbed as the jury's verdict was announced.
The Judge said Ms de Campos Silva's life was cut short in a horrific manner by his actions.
Diego Costa Silva called emergency services early in the morning of 4 November 2021 and told them initially, he thought he had killed his wife.
When gardaí arrived at the apartment in Finglas, they found the body of 33-year-old Fabiole Campara de Campos Silva lying in a doorway between the bedroom and the hallway. Her head had been severed from her body.
Mr Costa Silva said he believed she had been possessed by the spirit of a gang leader from Brazil and was a serpent who was going to kill him. He said he had cut her head off after attacking her as that was the only way to kill the serpent.
He had been detained under the Mental Health Act in Dublin city centre two days previously by gardaí who saw him running through the city centre barefoot, wearing only shorts.
He was taken to the Mater Hospital and assessed but he left hospital the next day and killed his wife in the early hours of the following morning.
The court heard Mr Costa Silva had been using cannabis for a long time and told gardaí he would smoke up to three joints a day if he had it.
He said his wife had asked him to cut down and he said he had last smoked weed a few days before the killing.
The jury also heard that Ms de Campos Silva told doctors in the Mater that she had noticed a change in her husband's behaviour on 30 October. He had become paranoid and thought she was going to hurt him.
When she arrived to pick him up on 3 November, he initially hid from her before eventually being driven home by her.
Two consultant forensic psychiatrists gave evidence that Mr Costa Silva was suffering from a cannabis-induced psychotic disorder.
The jury heard that this was a recognised mental disorder under the legislation allowing the jury to bring in a special verdict of not guilty by reason of insanity if they found he did not know the nature of what he was doing, or that it was wrong or that he could not stop himself.
The court was also told that it was not the same as being intoxicated which is not a defence to murder.
Dr Mark Joynt for the prosecution said the effects of intoxication would only last while someone was taking the drug or for a short time afterwards. Mr Costa Silva remained in a psychotic state until 15 November, eleven days after the killing.
Prosecuting counsel, Shane Costelloe described this as a particularly horrible and deeply tragic case. A young woman had lost her life and Mr Costa Silva had killed the woman he was married to for years.
Defence counsel, Garnet Orange, told the jurors the evidence only pointed in one direction and only one verdict was possible - a verdict of not guilty by reason of insanity.
The jurors spent two hours and 24 minutes deliberating before reaching their unanimous verdict.
Judge McGrath said there were aspects of the case which were difficult to listen to and he excused them from jury service for the rest of their lives.
Mr Costa Silva has been remanded to the Central Mental Hospital for 14 days. There will be a further hearing on 22 March at which evidence about his current mental state will be heard.
The judge said Ms De Campos Silva was a young woman who had her whole life in front of her until it was cut short in a horrific manner by the actions of Mr Costa Silva.
He said there was little the court could say to ease the great loss, trauma and shock that her family must have endured and continue to endure - as a result of the loss of their daughter.
He said he wanted to extend his condolences to her family and friends on such a great and tragic loss.
