A man who was suffering from a severe case of obsessive compulsive disorder killed his housemate because he believed if he did not do so he would spend an eternity in hell, a consultant psychiatrist has told the Central Criminal Court.
Dr Ronan Mullaney told prosecution counsel Ronan Kennedy SC that when Sean Murphy stabbed Michael Olohan to death, Mr Murphy was "acutely psychotic" and was unable to refrain from the killing because he was convinced that he was "saving himself and the world from very great harm".
The jury has been told that where a person is unable to refrain from their actions because of a mental disorder they shall be found not guilty by reason of insanity.
Dr Mullaney said that if the jury is not satisfied that an insanity verdict is made out, it still remains that Mr Murphy was suffering from a mental disorder that "substantially impaired his capacity to refrain" from his actions such that he would qualify for a verdict of not guilty of murder but guilty of manslaughter due to diminished responsibility.
Professor Keith Rix has previously told the jury that he does not accept that Mr Murphy was psychotic. Professor Rix, who was unavailable to complete his evidence today due to ill-health, said that in his opinion Mr Murphy was able to resist stabbing Mr Olohan, as he had done on previous nights when he considered stabbing his housemate.
Dr Mullaney disagreed, saying: "I believe that his beliefs were utterly true to him and he was trying to balance what he thought was the right thing to do but his thinking was entirely based on faulty inferences because he was psychotic and delusional."
Mr Murphy (29) with an address at Bradóg Court, St Lawrence Road, Clontarf, Dublin 3, has pleaded not guilty to the murder of Michael Olohan (35) at the apartment they shared on St Lawrence Road on August 13th 2020. Mr Olohan is originally from Poppintree in Ballymun, north Dublin.
The jury has been told that at the time of the stabbing the accused and deceased lived together at Bradóg Court in a "step-down independent living facility" run by St Vincent's Hospital Psychiatric Services.
Mr Kennedy, for the prosecution, told the jury in his opening speech that Mr Olohan had lived there for some years while Mr Murphy moved in four months previously having been discharged from the psychiatric ward of St Vincent's Hospital.
Dr Mullaney detailed Mr Murphy's long history of psychiatric issues going back to his teenage years. Mr Murphy was first diagnosed with obsessive compulsive disorder (OCD) aged 15 and was committed to a psychiatric hospital aged 16.
He managed to complete his leaving certificate exams, achieving good results despite missing long periods from school due to his illness and went on to complete a science degree in the Dublin Institute of Technology on Kevin St.
His mental health deteriorated after that resulting in further hospitalisations and a period of homelessness during which Mr Murphy came to the attention of gardai due to his bizarre behaviour, the psychiatrist said.
Mr Murphy was later committed to St Vincent's as an involuntary patient after gardaí arrested him following reports from concerned members of the public that Mr Murphy had been staring at and talking to a tree for several hours.
Mr Murphy spent nine months on the psychiatric ward in St Vincent's before being moved to Bradog Court because his condition had improved. However, in a letter written by Mr Murphy to his treating team after the fatal stabbing, Mr Murphy revealed that he had been having thoughts about killing someone for about two years.
Reading from the letter, Dr Mullaney said the accused recalled that there were times he could ignore those thoughts and felt "happy and content" but those times became less frequent. In Bradog Court, he said, he "pieced together" a plan to kill Mr Olohan.
He said: "I realised I now had a way I could kill someone, that I could kill Michael by stabbing him in his bedroom." He described the urge to kill as a "ritual" and said he had a "need to kill or bad things will happen".
He said there were a number of nights before the actual stabbing when he went into Mr Olohan's room "with a knife in hand ready to kill him but then my thoughts would change" and he would stop himself.
He said he thinks about Mr Olohan every day and the "look on his face as he woke up and the roar as he realised what was happening".
He said: "Even though I know I was sick and there weren't any bad intentions, I still feel guilty and ashamed all the time."
During interviews with Dr Mullaney this year, Mr Murphy said that he got on well with Mr Olohan, and they had no arguments.
Visions of hell
Mr Murphy said that he believed at the time that if he did not kill someone that his "visions of hell" would come true, and he would "have to suffer for all eternity". He said he awoke at about 5am and took a knife from the kitchen that he had bought some weeks earlier with the intention of killing someone.
He described going into Mr Olohan's room before experiencing a "frenzy" and feeling that he wasn't in control of his own actions.
He described his obsession about going to hell as "torture" and said he had been close to killing others before he killed Mr Olohan. He thought that if he did not carry out the killing the "torture would continue and I would never be free of it".
Dr Mullaney said that having considered Mr Murphy's long psychiatric history and all relevant evidence, he believes the accused was suffering from acute and severe OCD with psychotic features prior to, during and after the stabbing.
Referring to the Criminal Law (Insanity) Act, Dr Mullaney said that if an accused person was suffering from a mental disorder at the time of an offence that made them unable to refrain from their actions, a jury shall return a special verdict of not guilty by reason of insanity.
Dr Mullaney said OCD is a mental disorder and Mr Murphy was unable to refrain from his actions although he did understand the nature and quality of his actions and that what he was doing was wrong. He was "unable to appreciate that acting on his compulsion would be irrational," the psychiatrist said.
The trial continues tomorrow in front of Ms Justice Mary Ellen Ring and a jury of six men and six women.