The trial has opened of a 42-year-old man charged with the murders 17 years ago of two women who lived in sheltered accommodation in Dublin.
Mark Nash has pleaded not guilty to the murders of Sylvia Shields, 59, and Mary Callanan, 61, who lived in a house attached to St Brendan's Psychiatric Hospital in Grangegorman between 6 March and 7 March 1997.
The Central Criminal Court was told that DNA samples from the two women were found on Mr Nash's jacket as a result of new tests at the forensic science laboratory in 2009.
The jury was also told that Mr Nash, who had last addresses at Prussia Street and Clonliffe Road in Dublin, had confessed to gardaí that he had carried out the murders, but subsequently withdrew those admissions.
In its opening statement to the court today, the prosecution told the jury that the two pillars of evidence against Mr Nash are his own admissions and DNA analysis.
The bodies of Ms Shields and Ms Callanan were discovered in sheltered accommodation in a house attached to St Brendan's Psychiatric Hospital on 7 March 1997.
The court heard their bodies were badly mutilated.
Both were partially clad, both suffered multiple stab wounds and the weapons used were from the kitchen - serrated blades, a knife, a large carving knife and a carving fork.
During his detention for another crime, the court heard that Mr Nash admitted killing the two women. He told gardaí he had been walking home in Dublin, went into the house and stabbed them in their sleep.
"My mind was disturbed at the time", the court heard he said, "you have to understand that".
He subsequently withdrew those admissions, saying he was "shocked they had been taken seriously", but understood why.
The court heard he said he "would have taken the rap for killing the Pope if he had enough knowledge", but insisted he had absolutely nothing to do with Grangegorman.
He later wrote in a suicide note in Mountjoy, the court heard, that he had seen what happened in the house that night because he had seen someone running from the scene and had gone to investigate.
He wrote that what he saw in the house that night has haunted him and "if you saw it perhaps you would go mad as I did".
The court also heard that a bloodstain found on a button on the sleeve of Mr Nash's jacket in 1997 could not be developed as a DNA sample.
However, the jacket was analysed again at the forensic science laboratory in 2009 and DNA from both victims, Ms Shields and Ms Callanan, were found in what the prosecution described today as a spectacular breakthrough.
The trial continues.
