A jury at the Central Criminal Court has heard a 34-year-old man who is on trial for the murder of his girlfriend had a long history of psychiatric illness.
Oisin Conroy, from St Joseph's Terrace, Boyle, Co Roscommon, has pleaded not guilty by reason of insanity to murdering 23-year-old Natalie McGuinness in October 2015.
The court heard he had stopped taking anti-psychotic medication in the months before the killing and his family had become concerned about him.
The court was told expert witnesses for both the prosecution and the defence agree that Mr Conroy was suffering from a psychiatric illness when he strangled Ms McGuinness at his home at Mail Coach Road in Sligo.
A forensic psychiatrist for the defence said he suffered from schizophrenia which persisted for months after the killing despite aggressive treatment in hospital.
Dr Fiona Toal said Mr Conroy's condition may have been masked in earlier life due to his drug use. She said at the time of the killing he was suffering from delusions.
Opening the case to the jury, prosecuting counsel Tara Burns said the accused man and Ms McGuinness had been in a relationship for a relatively short period of time. She had been very good friends with his sister and began a relationship with Mr Conroy.
The night before she was killed she had been dropped off at his house and spent the night there. The following morning Mr Conroy rang 999 and said he had strangled his friend. Emergency services, including the Garda Armed Response Unit, attended the scene.
Ms McGuinness' naked body was found unresponsive in a bedroom. She was pronounced dead soon afterwards and a post-mortem examination showed she had been strangled.
The accused man had suffered a self-inflicted very significant knife wound to his head which was the cause of a lot of blood at the scene, the jury was told.
He was treated in hospital and was arrested and taken to a garda station but had to return to hospital for further treatment before being brought back to the garda station for interview. During this time he made a number of admissions to gardaí, the court was told.
Defence counsel Brendan Grehan told the jury the sole issue in this trial would be the mental state of the accused.
He said his client admitted he caused the death of Ms McGuinness by strangulation.
Detective Sergeant Patrick Harney told the court Ms McGuinness had been dropped off at her boyfriend's house by her parents the night before she was killed.
She had been expected home the following evening for a fitness class. Both she and Mr Conroy had an interest in fitness and martial arts.
Shortly after 10am the next day Mr Conroy called emergency services and said: "I've killed my friend. I've strangled her. I gave her a rear naked choke hold."
He said emergency services attended the scene and Ms McGuinness' body was found on the floor of the bedroom.
Mr Conroy had a wound to his head through which his skull could be seen. Both were taken to hospital.Ms McGuinness was pronounced dead in hospital a short time later.
A post-mortem examination found she had been strangled. The State Pathologist concluded there was no evidence of a prolonged assault and the cause of death was strangulation.
After his arrest Mr Conroy was interviewed by gardaí and gave a series of bizarre answers to their questions.
He told them he had killed his "beautiful, fragile wife" and that something had come over him and he felt he had to "kill her, kill her, kill her."
He described how he strangled her using a martial arts "rear naked choke hold."
He also told gardaí that he had cut himself then walked into the bedroom and saw her sleeping and felt he had to kill her.
He also spoke of struggling with the Devil and Jesus and being filled with fear he could not process. He spoke of "being in the matrix"
Sgt Harney agreed with Mr Grehan that it was immediately clear they were dealing with very bizarre behaviour and they were not dealing with normal interactions. He also agreed that at times Mr Conroy appeared to be "somewhere else" and talking to other people.
The court was told Mr Conroy had a history of psychiatric illness and had engaged with mental health services. He had returned to education after a chaotic childhood and had acquired a degree in English and Philosophy.
He was twice admitted as a psychiatric in patient and had been released on an anti-psychotic drug but had stopped taking them.
He was seen by an outpatient services in September 2015 and it was noted he had stopped taking his medication. This was six weeks before he strangled Ms McGuinness.
Various social workers and counsellors were involved in his treatment and care as an outpatient in the time leading up to Ms McGuinness' killing. After his arrest and detention Mr Conroy was transferred to the Central Mental Hospital.
Dr Toal told the court Mr Conroy had a history of psychiatric illness combined with problems with drug and alcohol abuse and had suffered a number of psychotic episodes.
He had a number of previous criminal convictions for offences including burglary and assault related to substance and alcohol abuse.
She examined him in January 2016 and there was still some evidence of psychosis present.
Mr Conroy showed some insight into his illness and said he was upset because his mind had tricked him into killing someone.
He told her he had not slept for days before the killing and on the morning he had tried to skin himself alive.
He thought he was in 'the matrix' and had to kill Natalie to help her escape. He said he was sceptical of medication because when he was on it he thought he had to kill his family.
Dr Toal said members of his family had become concerned about him in the days before the killing but he had refused to go to hospital, saying they could not help him.
Since his admission to hospital following the event he continued to suffer from severe symptoms for several months despite aggressive treatment.
She concluded he suffered from schizophrenia, which may have previously been misdiagnosed because of his history of drug use.
She noted that during a previous admission to hospital for a psychotic episode his drug and alcohol screening had been negative.
Dr Toal told the court that after the killing his classic symptoms of schizophrenia had persisted for months despite heavy medication and aggressive intervention.
She said he will require protracted, intensive treatment at the Central Mental Hospital.
The case continues tomorrow.
