Mairead died from multiple stab wounds to heart and other organs
Mairead Moran died from two stab wounds that penetrated her heart and other internal organs following a "frenzied" attack, the Central Criminal Court has heard.
State Pathologist Professor Marie Cassidy told the jury that Ms Moran (26) suffered a total of eight stab injuries in the attack and another six cuts.
Of the two deepest wounds, one pierced her heart and left lung, and the other entered her liver and right kidney.
Prof Cassidy determined that the assault most likely came from the side, rather than in a face-to-face encounter.
She also noted that injuries to Ms Moran's hands suggested "struggling or defensive actions".
Prof Cassidy was giving evidence in the trial of Shane Smyth, who denies murder by reason of insanity.
Mr Smyth fatally stabbed Ms Moran with a dagger after dragging her out of the store where she worked at Market Cross Shopping Centre, Kilkenny, on May 8, 2014.
Mr Smyth (29) had been diagnosed with paranoid schizophrenia and believed Ms Moran was involved in a conspiracy against him.
Prof Cassidy said in a post-mortem examination she noted eight stab wounds and six incised wounds or cuts to Ms Moran's head, left arm, chest, right back and right hand.
One of the two deep stab wounds had continued through the left arm into the left side of the chest to penetrate the heart and left lung.
The other, to the right lower back, had penetrated the right kidney and liver. Both of these were potentially fatal injuries.
"The injury to the heart in particular would cause fairly rapid collapse and could cause death due to arrhythmia or cardiac failure," Prof Cassidy said.
"The pattern of injuries to the left arm and right hand suggest movement of the arms due to struggling or defensive actions.
"Death was due to stab wounds to the trunk (causing) injuries to the heart, left lung, right kidney and liver."
Prof Cassidy said the injuries were consistent with "a blade with a single sharp cutting edge".
Meanwhile, a forensic psychiatrist concluded in a report that Smyth - with an address at McGuinness House, Evans Lane, Kilkenny - was not capable of forming any intent at the time of the killing.
"In my opinion, he was so disordered in his reasoning and thinking at the time he was not in a position to appreciate the nature and quality of his actions," Dr Paul O'Connell said.
"I don't think he was capable of forming any specific intent. He was incapable of forming any moral judgement about what he was doing at the time," he said.
The trial continues.