A 46-YEAR-OLD woman has gone on trial at the Central Criminal Court, having pleaded not guilty by reason of insanity to the murder of her flatmate in their South Dublin home.

Mercy Peters is charged with murdering Tyrone McKenna (42) on 17 July, 2014 at the house they had shared in Marley Court, Rathfarnham. She entered her plea this morning, and a jury of eight men and two women was sworn in to hear the two-day trial.

Paul Burns SC, prosecuting, told the jury that there was no dispute but that Ms Peters had killed Mr McKenna.

“She killed him by stabbing him,” he explained. “The real question for you is whether she’s entitled to the special verdict of not guilty by reason of insanity.”

He said that the jury would have to decide if, at the time, she was suffering from a mental disorder.

If she was, it would have to decide if she knew the nature and quality of the act committed, or knew that it was wrong or that she was unable to refrain from it.

He informed the jury that both the consultant psychiatrists for the accused, and for the prosecution, were of the view that Ms Peters met the criteria for the insanity verdict.

However, he explained that the law required such a verdict to be returned by way of a jury.

The trial continues this afternoon before Mr Justice Michael White.