The State Pathologist has been giving evidence at the trial of Joe O'Reilly who is charged with the murder of his wife Rachel in October 2004.
Mr O'Reilly is pleading not guilty to the charge.
Dr Marie Cassidy said that Rachel O'Reilly could have died several hours after she received extensive head injuries in the bedroom of her home in The Naul, Co Dublin.
She gave detailed evidence about the post mortem examination carried out on Rachel O'Reilly the day after Mrs O'Reilly was murdered.
Dr Cassidy concluded that Mrs O'Reilly died as a result of blunt force trauma and the inhalation of blood.
Mrs O'Reilly had received eight lacerations to the head, resulting in a fracture of the skull and damage to her brain.
The injuries could have been inflicted by four separate blows, she said.
There was evidence that Mrs O'Reilly attempted to defend herself as she had some bruising on her arm and wrist.
Prof Cassidy estimated that the time of death was between 9am and 3pm on 4 October 2004.
Evidence was also heard this afternoon from the Detective Inspector who examined notes and letters taken from Rachel O'Reilly's coffin.
He said the five page letter from Joe O'Reilly was one of several notes, letters and birthday cards left there by family and friends.
