Mark Nash trial: Forensic expert tells jury no traces of blood stains found on jacket

Dr Fiona Thornton told court she carried out a visual examination on black velvet jacket for blood stains but didn’t find any

Mark Nash who is accused of murdering Sylvia Shields (60) and Mary Callanan (61) between March 6th and March 7th, 1997.
Mark Nash who is accused of murdering Sylvia Shields (60) and Mary Callanan (61) between March 6th and March 7th, 1997.

A forensic scientist told a murder trial jury she found no traces of blood stains on a jacket worn by a man accused of murdering two women 18 years ago when examined in August 1997.

Mark Nash (42) who has last addresses at Prussia Street and Clonliffe Road in Dublin, has pleaded not guilty at the Central Criminal Court to the murder of Sylvia Shields (60) and Mary Callanan (61) between March 6th and March 7, 1997.

Dr Fiona Thornton who was attached to the Forensic Science Lab in 1997, now Forensic Science Ireland, went to Orchard View in Grangegorman on March 7th, 1997 with Dr Louise McKenna and later attended a postmortem carried out by now retired State pathologist John Harbison, where swabs of the bodies of Sylvia Shields and Mary Callanan were taken.

Dr Thornton told the court she examined the swabs with a high-powered microscope, looking for the presence of semen but did not find any.

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Dr Thornton told counsel for the State, Ms Una Ni Raifeartaigh SC, that on August 18th, 1997 she then received four more items belonging to the accused Mark Nash which included a pair of boots, a second pair of black leather caterpillar boots, a black pin-striped velvet jacket which was received in a sealed, stapled brown paper bag and a black pin-striped suit.

Dr Thornton told the court she carried out a visual examination on the black velvet jacket for blood stains but didn’t find any.

“It would have required a decent-sized stain, the size of a 50 cent piece. I didn’t carry out an examination under a microscope or any other high powered aids,” said Dr Thornton.

Dr Thornton also told the court she did not find any blood on the two pairs of boots either.

Dr Thornton told the court she would wear protective clothing when examining items, the bench would be wiped down with a bleached type liquid and only one item would be examined at any one time and once examination of the item was completed it would be put back into the bag.

Dr Thornton said she put the black velvet jacket back into the bag after its examination and rolled the bag down.

Cross examined by Mr Hugh Hartnett SC for the accused, Mr Hartnett said how “things have come on in leaps and bounds since 1997 and it is now possible to get DNA from things that are invisible to the human eye and a microscope”.

“If sufficient DNA has landed you would be able to generate a DNA and can generate a DNA profile for a very small amount,” replied Dr Thornton.

Mr Hartnett asked Dr Thornton, “Do labs now take take greater precautions of eliminating the possibility of contamination?”

“We do things differently,” replied Dr Thornton.

Mr Hartnett said to Dr Thornton that she didn’t reseal the the bag of the black velvet jacket at the time?

Dr Thornton told the court she turned down the bag as it was going to her colleague Mr Michael Norton on August 27th, 1997.

“At that time I had carried out my examination, I put it in the bag, folded down the top of it and handed it to my colleague and he handed it back to me on the same day,” said Dr Thornton. “There was probably no need for me to reseal the bag, to give it to him, ” added Dr Thornton.

The trial continues.