Ross O'Rourke found not guilty of father's murder by reason of insanity

This report is a localnews.ie summary based on public court reporting and records; sources are listed below.

Ross O'Rourke has been found not guilty of murdering his father, Stefan Nivelle Posschier, by reason of insanity by a jury at the Central Criminal Court. He had pleaded not guilty by reason of insanity to the murder charge. The proceedings were reported on 15 December 2025.

The jury heard that Mr O'Rourke stabbed his father 18 times during an acute psychosis after developing delusions that his father was linked to criminals and the IRA, posed a threat to his life and had sent a coded message that he wished to die. The prosecution said he intended to kill his father, while defence and prosecution psychiatrists agreed that he met the criteria for the special verdict.

Dr Ronan Mullaney said Mr O'Rourke's mental disorder meant he was unable to refrain from killing his father. Dr Anthony Kearns said he understood the nature and quality of his actions but did not understand that they were wrong because of his sincere delusional belief. Mr Justice Paul McDermott exempted the jury from further service for five years; ongoing hospital treatment was recommended.