A man was found guilty but insane of the murder of his grandmother in 1996 at her home in Thurles, Co Tipperary, in the Central Criminal Court yesterday.
Mr Justice Shanley ordered that he be detained at the Central Mental Hospital in Dundrum.
Declan Molumby (24), of St Ailbe's Terrace, Thurles, had pleaded not guilty to the murder of Mary Molumby (86) in Archerstown, Thurles, on or about March 8th, 1996.
Dr Helen O'Neill, a psychiatrist at the Central Mental Hospital, told the court that Molumby had been suffering "acute schizophrenia" in March, 1996.
Dr O'Neill said that Molumby had been experiencing "persecutory delusions" and hallucinations which led him to be "out of touch with his surroundings".
In a statement to gardai which was read to the jury, Molumby told how an argument had developed between himself and his father over a traffic fine Molumby had incurred. The argument began as they travelled to his grandmother's house on February 16th, 1996.
When they arrived at the house, the accused man found a lump-hammer in the car, with which he proceeded to hit his father about the head.
His father ran to get help and warned Mrs Mary Molumby and the accused man's uncle, Mr Jack Molumby, to "lock themselves up" in the house.
Declan Molumby said he struck his grandmother twice about the head, shoulders and hands, and he struck his uncle also. He then put the two people into his trailer and drove to an isolated spot, where he dumped them. The uncle survived, but the grandmother later died from her injuries.
"I just freaked out", he told gardai. "I just kept hitting out at both my grandmother and uncle and they fell down on the floor of the kitchen."
The jury was told Mr Patrick MacEntee SC, defending, that the question with which they were concerned was: "What was the state of mind of Declan Molumby when he struck the blows to his granny?"
If the mental illness left the accused man "incapable from refraining from doing what he did", even though he knew the immoral nature and the likely consequences of the act, then the jury could say he was legally insane.
Molumby had told gardai that he heard voices commanding him to kill his grandmother and his uncle and that he had feared for his own life as a result. He had a "fixed stare" in his eyes while being questioned by gardai and had mumbled "jibberish" to himself.
Other symptoms of illness demonstrated by Molumby at the time were persistent humming to himself and the way he kept rubbing his hands in a vigorous manner.
After Molumby's admittance to the Central Mental Hospital three psychiatrists had diagnosed him as schizophrenic and he had been treated with anti-psychotic drugs.
Molumby had responded well to treatment and a relapse after he neglected to take his medication was further evidence of the mental disease which had led to the killing, Mr MacEntee told the jury.
"He felt compelled, quite irrationally, because of his psychosis, to carry out the killing", defence counsel said.
After deliberation lasting 1 1/4 hours the jury returned a unanimous verdict of "guilty but insane".
Mr Justice Shanley ordered that Molumby be detained at the Central Mental Hospital until the Government decided otherwise.