A consultant neuro-pathologist has told the Millie Martin murder trial that an injury to the back of the child's head was "fatal" from the moment it was struck, setting off a chain of events which were irreversible.
Dr. Brain Herron told prosecution QC Ciaran Murphy the head injury caused the brain to swell, resulting in that section of the brain, dealing with the "basic functions" such as breathing, swallowing and heart rate, being crushed "and that's what happened in Millie's case".
Millie's 27-year-old mother, Rachael Martin, of Main Street, Kesh, and her former boyfriend, 33-year-old Barry McCarney, of Woodview Crescent, Trillick, both deny charges arising from her death.
Dr. Herron told Dungannon Crown Court: "What happened to Millie was so severe she would have been extremely ill and most likely unconscious."
He said he thought the onslaught of unconsciousness would have been "probably immediate''.
Under cross-examinations by McCarney's defence barrister, Elis McDermott QC, it was revealed that defence and prosecution experts had met in London in August, where it was agreed Millie's injuries were "non-accidental''.
However, while Dr. Herron estimated the fatal head injury was "less than two to three days old'' and that it was "sustained shortly before the child was admitted to hospital..... it was not possible to be precise as to when this occurred''.
The doctor also told McCarney's lawyer that he could not narrow down the time "to two minutes or even half an hour ...... I can't be that accurate''.
Later Northern Ireland State Pathologist Professor Jack Crane told the court of finding multiple injuries on Millie including a 25 centimetre bruise from an injury to the back of her head which ultimately caused her death.
This injury he claimed had been caused "by blunt force trauma to the back of the head, possibly a wall or the floor .... most likely by the head being impacted on a hard surface," rather than a blow to her head.
The professor further claimed the injury could not be explained away simply by Millie falling backwards and hitting her head and the more realistic explanation was that she was being held "when her head was impacted on the hard surface".
Among other injuries were some to Millie's genital area, which Professor Crane claimed had resulted from a sexual assault on the infant.
In a summary to his four-hour autopsy, the State Pathologist concluded: "Death was due to a head injury which she sustained."
He added that while injuries to children were "often problematic .....in this case however, there is unequivocal evidence of a severe impact injury to the back of the head with possible further impacts to the front and right side.
"The severity of the injury was such that it is likely to have resulted in rapid loss of consciousness and therefore it seems that it must have been sustained very shortly prior to her being admitted to hospital", and given the multiplicity and location of other injuries suggested they too were non-accidental.
Professor Crane later added that Millie had "also been recently sexually assaulted" and that injuries to her groin area were "consistent with the attempted insertion of a hard object ...."
"In summary, this child died as a result of a serious head injury inflicted shortly before her admission to hospital. She had also recently been sexually assaulted ... and bruising to her abdomen and bowel were probably caused by her having been prodded or punched," he stated.
The trial continues.