A MAN with schizophrenia thought his mother had been replaced by an impostor when he killed her at home last year, a court has heard.
Niall Stapleton (32), of Glebe Lodge, Kilfane, Thomastown, Co Kilkenny, has pleaded not guilty to the murder of Siobhan Stapleton (51) at that address on May 25, 2012. She died from blunt force trauma to the head after being beaten with the handle of a garden fork.
The Central Criminal Court heard that the college graduate maintains that he is not guilty by reason of insanity.
Consultant forensic psychiatrist Dr Stephen Monks testified on behalf of the defence yesterday. He had examined Mr Stapleton in the Central Mental Hospital, where he has been since shortly after his mother's death.
Dr Monks said his opinion was that the accused was suffering from a mental disorder at the time of the killing.
"He had active symptoms of schizophrenia," he said.
He added that Mr Stapleton had a delusional belief at the time that his mother had been replaced by an impostor or doppelganger.
It was Dr Monks's opinion that Mr Stapleton's mental disorder was such that he didn't know the nature and quality of his act, didn't know that what he was doing was wrong and was unable to refrain from it.
"I think he fulfils the criteria for the special verdict of not guilty by reason of insanity," he said.
He added that if such a verdict was reached, he would recommend the accused remain at the Central Mental Hospital.
The court later heard how Mr Stapleton thought the house he was living in was haunted and had begun sleeping in his car and in the woods.
Dr Monks said that the accused had a history of poor compliance with taking his medication, having often complained of the side effects.
He said that he had also failed to turn up for a number of outpatient appointments.
The trial continues before Mr Justice Garret Sheehan.