Deputy State pathologist Dr Marie Cassidy today told the inquest into the 1996 death of Raphoe cattle dealer Richard Barron his fatal head injuries were the result of a road traffic accident.
Det Supt John McGinley, who was stationed in Letterkenny in October 1996, told the inquest the case was initially treated as a hit-and-run but changed to an investigation of suspicious circumstances or foul play.
He said there was no evidence found at the scene to suggest a vehicle and no traces on the deceased's clothing. He added that the first post mortem showed Barron's injuries were found to be not consistent with a road traffic accident.
When asked if he still considered the matter a murder investigation, Supt McGinley replied that he had "an open mind on the matter as to how the deceased met his death".
Dr Cassidy told the inquest she received a request from Supt Tadhg Foley to conduct an independent post mortem following last year's exhumation of Barron's body.
Citing the two points of impact to the deceased's skull to the left base of the skull and then the forehead she stated "in the absence of any other significant injuries" the injuries occurred as the result of a road traffic accident.
"It is highly unlikely these injuries would have resulted from an assault," she added.
Referring to the striations or scuff marks on the front area of the skull noted by State pathologist Professor John Harbison, Dr Cassidy said an object would have to strike the head with considerable force to produce such grooves in the bone. If it had been struck with that amount of force more extensive fractures would have been expected.
Dr Cassidy offered the view that the possible cause of the bone striations was the head being moved along an uneven surface such as a road surface.
However she acknowledged, when questioned by Mr Donagh McDonagh SC for the Barron family, that it was unusual that there was no grit or tar from the road on the skull, but added that it does happen.