Doctor tells Kayden McGuinness murder trial that no single injury can be identified as cause of death
A medical expert has told the trial a man accused of killing three-year-old Kayden McGuinness that it was pure conjecture to say which injury caused his death.
Dr Michael Farrell, a consultant neuropathologist at the Beaumont Hospital in Dublin, was called as a defence witness to give evidence in the trial of Liam Whoriskey (25), from Glenabbey Gardens, in Londonderry.
Whoriskey denies causing the death by manslaughter of Kayden in the child's Bogside home just over two years ago. He also denies causing the child's death by neglect and a charge of child cruelty.
It is alleged that the offences took place at Colmcille Court between September 16 and September 17, 2017, when he was babysitting Kayden and his five month old baby sister. Kayden's mother, Erin McLaughlin, the defendant's fiancée, was out socialising.
Dr Farrell told the jurors, when questioned by defence barrister Ciaran Mallon QC in relation to the fifteen bruises found on Kayden's scalp, that timing of and dating of when the blows were inflicted was a very difficult and precise science.
He said it was not possible to say which of injuries had triggered a swelling of the child's brain resulting in the catastrophic bleeding and continued swelling of the brain.
"There was not, if you like, one killer blow", he told the jurors.
He said the "core of the pathological problem" was that the timing of Kayden's death has not been ascertained. Dr Farrell said he could not say how the injuries were caused but he said they were consistent with non-accidental injuries which precipitated a cerebral oedema.
Dr Farrell said he ruled out as contributory factors to Kayden's death meningitis, a seizure, a heart or lung disease and he said there was no evidence of poisoning nor of a renal disease.
He said the blunt force trauma injuries to Kayden's scalp could have been caused by someone grabbing the child by the head. There was no fracture of the skull and he said that a single blow or a number of blows "can trigger a cascade of brain swelling".
Asked by Mr Mallon if Kayden's unusual behavioural pattern on the day before his body was found in his bed could indicate anything unusual, Dr Farrell said any alteration to behaviour of a child was consistent with concussion.
Cross examined by prosecution barrister Peter Irvine QC, Dr Farrell said it was possible that Kayden had been grabbed by the head but it was equally possible that he sustained multiple injuries to the head.
He also said that tiredness in a child was also a symptom of concussion. He said the defence and prosecution submissions in relation to the cause of death "are diametrically opposed" and he added "we are all at the mercy of the clinical story". Dr Farrell said he believed it was more likely than not that the scalp injuries were inflicted at the same time.
The defence case has ended. The prosecution and defence barristers will make their closing speeches on Tuesday, October 15
Belfast Telegraph Digital