The trial of a 42-year-old man accused of a double murder has heard that he admitted killing two women in Dublin 18 years ago and DNA found on his jacket corroborated his admissions.

Mark Nash, who has last addresses at Prussia St and Clonliffe Rd in Dublin, has pleaded not guilty at the Central Criminal Court to the murders of Sylvia Shields, 60, and Mary Callanan, 61, between the 6 and 7 March 1997.

The prosecution began its closing statement this afternoon. Mr Nash denies the murdering two women who were living in sheltered accommodation in a house attached to St Brendan's Psychiatric Hospital in Grangegorman, Dublin.

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 and that Mr Nash had also confessed that he had carried out the murders, but subsequently withdrew those admissions

Senior Counsel Brendan Grehan told the jury that the suggestion that "DNA was blowing around a lab like snow in a blizzard" and that contamination can account for the DNA evidence is a desperate and failed attempt to explain away the blindingly obvious.

He said the women's DNA recovered on Mr Nash jacket got there during the murders, not because contamination was rife and cleaning standards were akin to some back street garage.

He also told the jury that Mr Nash had made admissions to the murders to both the Gardaí and a priest, and that the DNA was powerful corroboration of his guilt.

Mr Grehan also said, that at the time "no one was looking for Mark Nash for the murders, they had been solved, another man Dean Lyons and had been charged with one of them.  So what conceivable interest could gardaí have had in terms of prompting some sort of a statement?”

Mr Justice Carroll Moran told the jury that the last chapter of the case is all that remains.

The prosecution will continue its closing statement tomorrow, to be followed by the defence.