Dwyer's DNA on Elaine's bloody mattress
SEMEN found on a blood stained mattress in Elaine O'Hara's apartment matched Graham Dwyer's DNA, the Central Criminal Court has heard.
A forensic scientist told the jury that out of five semen stains discovered on the mattress from Belarmaine Plaza, Stepaside, a full DNA profile matching the accused was found on three areas.
There was also a "partial profile" match of Mr Dwyer on the two other semen stains and on two non-semen stains on the mattress, he said.
Dr David Casey, of the Forensic Science Laboratory, was giving evidence on day 26 of the trial of Graham Dwyer, who denies murdering Elaine O'Hara on August 22, 2012, in the Dublin Mountains.
He told Sinead McGrath, for the prosecution, he carried out DNA profiling on semen stains and on four areas of blood staining on mattress.
Two of blood stains had holes and the DNA profiles from those matched Ms O'Hara, he said.
The jury heard there were five stab or cuts and three small holes on the top end of the mattress. A bean bag cover that was found had blood stains that matched Ms O'Hara and there was also a stab cut to the material. No semen was found on the bean bag.
The court heard Dr Casey had 13 DNA samples to compare against the stains "ranging from family members of Ms O'Hara to persons of interest in the investigation."
The forensic scientist, who excluded the other samples as sources of the stains, confirmed the chances of the DNA profile coming from someone not related to Mr Dwyer was "less than one in a thousand million,".
Dr Casey also tested a lace up black PVC dress found in Ms O'Hara's apartment, but there was no semen on it and there was insufficient DNA on the knots of the lace or on the zip.
There was also insufficient DNA from a gas mask, lighter or a bottle of 'Passion' taken from the apartment. However, there was the DNA of at least two people found on a rope seized.
It was not known if these were male or female, he added, and they were not strong enough to interpret any further.
Separately, Dr Casey examined several items discovered in a second site in Killakee Woods, close to where Ms O'Hara's remains were found by a dog walker on September 13, 2013.
He told the court he could not find any DNA matches for the accused or Ms O'Hara on any of the items, which included a tracksuit bottoms with holes in them.
The black-coloured bottoms were in poor condition and covered in mud, dirt, staining and vegetation staining, he agreed, and the inside was stained from animal or insect activity.
However there was no semen or blood inside them.
The court heard there were three holes to back right thigh area of the clothing, and the crotch area was cut, but the scientist was "unable to rule out animal damage as a cause of damage".
There was also insufficient DNA from a waist band tie on the bottoms, or on another piece of clothing, he added.
Dr Casey said he also examined two condoms and a condom wrapper which were found at the second site.
Tests showed semen found inside and outside one of the condoms was the DNA profile for an unknown male and the accused was excluded, he said.
"Over time condoms would discolour and degrade because of exposure," said Dr Casey, when asked about how long they had been at the scene.
He added that both were used and in good condition, but given the absence of weathering, they were only there recently and not over a year.
Dr Casey also examined a spade found in the same area and found no blood on it.
The handle of a spade found was examined for skin cells and it showed low level partial DNA profile from at least two people, but it was too low to analyse further, the court was told.
Elsewhere, Dr Casey was involved in an examination of three cars from Mr Dwyer's family home - two Freelanders, both with a 02 D registration numbers, and a 99 G Audi TT.
He said he visually examined the vehicles for blood before using Bluestar chemical spray, a florescent light which highlights dried blood.
"After extensive searching of the vehicles, there was no blood presents," he said.
Ms O'Hara's DNA was not found in any of the vehicles.
The trial continues.