Northern Ireland's Assistant State Pathologist has told the trial of a twenty-five years old man who denies murdering his fiancée's three years old son just over two years ago, that the fatal injury which caused the child's death was not inflicted on the day the boy's mother, Erin McLaughlin, had the sole custody of her son.
Dr. Peter Ingram was giving evidence on the seventh day of the trial of Liam Whoriskey, a waiter from Glenabbey Gardens, in Derry.
The defendant denies murdering Kayden McGuinness in the child's family home, where the defendant also lived, between Saturday, September 16 and Sunday, September 17, 2017.
The defendant also denies two charges of child cruelty and one charge of child neglect.
He found Kayden's body in the child's bedroom in the family flat at 2b Columbcille Court in the Bogside area of the city just before 10 o'clock on the Sunday morning, the court heard.
The defendant had been babysitting the child and a five month old baby girl when their mother, Erin McLaughlin, had stayed out overnight after socialising with family members and friends.
Dr. Ingram told the jury of seven men and five women at the city's Crown Court that he carried out a post mortem on the body of Kayden on September 20 and September 21, 2017. He said two other consultants also attended the post mortem.
"There were multiple injuries on his body, mostly bruises and most of which were on his face and scalp. There were also some on the limbs and trunk. On the face there were four bruises on the right cheek including a large bruise on the centre of the cheek.
"There were three bruises on the left side of the forehead, up to seven bruises on the left cheek and a further bruise on the under surface of the chin.
"There was a small laceration, or tear, on the lobule of the right ear. There were also at least fifteen bruises on the scalp. These bruises were visible to the naked eye and, using the microscope, of a broadly similar age.
"They were all less than a few days old and quite possibly less than this. These injuries were caused by blunt force trauma to the head.
"As the result of one or more of these blows to the head, a thin film of bleeding, a type known as subdural haemorrhage, had developed over the surface of the brain and the brain had become swollen, termed cerebral oedema.
"The combination of the subdural haemorrhage and the cerebral oedema is indicative of severe blunt force trauma of the head and it was this which was responsible for the boy's death", Dr. Ingram told the jury.
"Death however is unlikely to have been immediate and indeed there were subtle changes in the brain indicating a period of survival of at least half an hour after the fatal head injury was sustained.
"Whilst it is not uncommon for young children of this age to sustain minor injuries from knocks and falls, the multiplicity of injuries in this case and their pattern and distribution clearly indicates that they were non-accidentally sustained and were as a result of his being assaulted, possibly repeatedly, over a period of time.
"The multiple bruising on the scalp, associated with the underlying injury to the brain, were due to his having been struck repeatedly on the head, possibly by punching. Similarly the bruising on the right cheek and on the under surface of the chin could have been caused by blows from a fist", he added.
Dr. Ingram said that a fracture of the child's fifth left rib could have been caused by forceful compression of the child's chest by squeezing.
"Thus, in summary, this young boy had sustained a large number of bruises caused by blunt force trauma to his face and head, undoubtedly as a result of non-accidental injury.
"As a result of the blows to the head there had been bleeding over the surface of the brain which had also become swollen. It was the effects of the head injury which were the cause of his death", he told the jurors.
Asked by prosecution barrister Peter Irvine Q.C. "if the trauma required to cause this subdural haemorrhage, if it is possible if it had occurred on the Friday of that week the child would have been able to survive until his death?", Dr. Ingram replied "absolutely not, no".
The trial continues.