Even had hammer-attack victim Anne Shortall survived her head injuries, she would not have endured her head being bound in duct tape, the Central Criminal Court has heard.
State pathologist Professor Marie Cassidy said she could not establish whether the mother-of-three survived the blows to her head but said the taping over of face "excluded all possibility of surviving".
Prof Cassidy said the head injuries alone could have caused death, which was "probably fairly rapid".
She said there were nine blows and found the cause of death was blunt force trauma to the head and obstruction of the airways.
Prof Cassidy was giving evidence for the prosecution in the trial of Roy Webster, who denies murdering Ms Shortall.
Previously, the jury heard how Mr Webster had told gardai that he wrapped Ms Shortall's head and wrists in duct tape after hitting her "three or four times" with a claw hammer.
Mr Webster (40), a father-of-two, from Ashbree, Ashford, Co Wicklow, denies murdering Ms Shortall (47) on April 3, 2015 at The Murrough, Co Wicklow.
He pleaded guilty to manslaughter but that plea was not accepted by the prosecution.
Prof Cassidy told the court that Ms Shortall's head was wrapped with silver coloured tape from chin to forehead, concealing the face and obstructing the nose and mouth. Tape around the wrists covered the sleeves of her jacket.
Ms Shortall had sustained nine blows to the head with a moderately heavy object with a small striking surface, she said.
This resulted in lacerations to the scalp and face, including injuries to her left ear, which was split.
There were five lacerations to the top of the head, another along the right ear, extensive trauma to her left ear, a laceration at the outer end of her left eyebrow and the last along her chin.
There were also bruises and abrasions to the hands that Prof Cassidy said could have been "defensive-type" injuries.
The skull had not been fractured. There was slight swelling to the brain but no evidence of direct injury and she was otherwise healthy.
There was no evidence of a pregnancy.
"The multiplicity of forceful blows to the head could have caused rapid concussion or unconsciousness," Prof Cassidy said. She told the jury this could cause death but was also "compatible with continued life".
There was "no evidence of a sustained attempt at strangulation".
It was not possible to determine if the tape was applied when Ms Shortall was still alive, she said.
"It can't be excluded that death was due to head injuries alone," Prof Cassidy said.
"If they were applied while she was still alive this would have excluded all possibility of surviving the head injury," she said of the head bindings.
She said a claw hammer produced as an exhibit was consistent with the injuries.
The jury also heard Ms Shortall knew she was not pregnant when she went to her GP three weeks after she had sex with Mr Webster.
The doctor, Geraldine O'Kelly, said Ms Shortall was referred on for a procedure that could not have been performed if she had been pregnant.