The State Pathologist, Dr Marie Cassidy, has been giving evidence in the trial of Wayne O'Donoghue, who denies murdering Robert Holohan but admits his manslaughter.
She told the Central Criminal Court how she found what she described as pin-point haemorrhages behind Robert Holohan's ears during her post mortem examination on his body.
She said that studies had found that 15 to 30 seconds of constant compression was required to produce these injuries.
Earlier the jury heard how he asked one of the volunteers searching for Robert Holohan with rescue dogs whether the boy's scent would be picked up if he was in a car.
Áine Dorgan is a volunteer with Irish Rescue Dogs, which assists in searches for missing people. She joined the search for Robert Holohan in the early hours of 5 January last, less than 12 hours after he had gone missing.
She searched the area around Ballyedmond Hill with Wayne O'Donoghue.
Ms Dorgan told the jury at the Central Criminal Court this afternoon that Wayne O'Donoghue asked her how successful the dogs were, what would happen if Robert Holohan was in a river and whether the dogs would pick up his scent if he was in a car.
She told him a bloodhound would be brought in if Robert Holohan was not found and she said Wayne O'Donoghue did not seem very enthusiastic about this prospect.
Mick Murphy, another rescue dog volunteer, said Wayne O'Donoghue told him he felt Robert Holohan might have gone searching the fields for his bicycle and could have fallen into a river.
Sylvia Phelan, a friend of Majella Holohan, said Wayne O'Donoghue told her, in the early hours of 5 January, that he had last seen Robert Holohan at 4.45pm the previous evening.
She said she felt the boy had been missing before then and that Wayne O'Donoghue was the last person to have seen him.
Earlier, the jury watched a second video tape of an interview which Wayne O'Donoghue recorded with gardaí following his arrest last Janaury.
In the tape he says he did not call gardaí or an ambulance after he killed Robert Holohan because he was panicking.
Later in the tape he described dumping Robert Holohan's body in a ditch near Inch Strand and thinking that this was a disrespectful thing to do. He said he resolved to return to Inch and place the body on the beach so that it would be found before returning home to commit suicide in the back garden.
