Forensic scientist tells court Caterpillar boot likely made mark on lino in murder house

Mark Nash
Mark Nash

A forensic scientist told a murder trial jury today that a mark on lino in a house where two women were killed eighteen years ago was likely to have been made by a brand of "Caterpillar" boot.

However, the court heard it was a newer boot than the boot attributed to the accused Mark Nash.

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 6 and March 7, 1997.

The two women were living in sheltered accommodation attached to St Brendan's Hospital in Grangegorman.

Today forensic scientist Mr John McCullough from the chemistry section of Forensic Science Ireland told counsel for the State, Mr Brendan Grehan SC, he carried out a comparison on the black caterpillar work boots belonging to Mark Nash on October 7 2014.

The court heard that the boots had been cut apart previously, having been recovered from the home of the accused on Clonliffe Road in Dublin on August 17 1997, five months after the killings in Grangegorman.

On October 13 2014, Mr McCullough told Mr Grehan that he received a piece of light coloured vinyl floor covering from the house at Orchard View in Grangegorman.

The members of the jury today saw the lino, which was a small area of about 2 cm square, with a partial footwear impression on it, which appeared to be in blood.

Mr McCullough told Mr Grehan that the piece of lino had been submitted to the lab in 1997 and the footwear impression had been examined by one of his colleagues but at the time, there wasn't a boot to compare it with

Mr McCullough told the court his colleague said at the time that it came from a particular type of caterpillar boot.

Holding up the soles of the caterpillar type 9 boots to the court, Mr McCullough told Mr Grehan the purpose of his examination on the boots was to determine whether the pair of caterpillar boots belonging to the accused, could have been imprinted on the lino.

A test impression, which is effectively a finger print of the boot sole, was shown to the court by Mr McCullough.

Describing the sole pattern to Mr Grehan, Mr McCullough said there was a "series of W shaped blocks on the heel of the sole."

The court heard there was an "absence of fine wavy lines" on the boot belonging to the accused, which would disappear with wear.

However Mr McCullough told the court, the patterns of the soles corresponded

“It corresponds in terms of line.  The heel corresponds to features present but not in terms of the wear" said McCullough.

“The soles are very worn and there is mechanical damage to part of the blocks, chunks missing, not just wear, physical damage. The boots are very worn, as evident on the soles" added Mr McCullough.

Cross examined by Mr Hugh Hartnett SC for the accused, Mr McCullough said the mark on the piece of lino was "likely to be made by a caterpillar boot but a relatively new one."

“In terms of wear it did match the impression on the lino but it is munlikely that much wear and tear would be on that boot” added Mr McCullough.

Another forensic scientist Dr Fiona Thornton also told the jury today that she found no traces of blood stains on a jacket worn by the accused Mark Nash, when examined in August 1997.

Dr Thornton told counsel for the State, Ms Una Ni Raifeartaigh SC that on August 18 1997 she received four items belonging to the accused Mark Nash which included a pair of boots, a second pair of black leather caterpillar boots, a black pin stripped velvet jacket which was received in a sealed, stapled brown paper bag and a black pin stripped 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 Ms Ni Raifeartaigh that she did not find any blood on the two pairs of boots either.

The next witness of the day was Mr Michael Norton who retired eight years ago from his position in the Forensic Science Lab and was involved in the chemistry area of the lab which included glass examination.

Mr Norton told Ms Ni Raifeartaigh that he examined a duvet cover and a blood stained sheet in July 1997 to look for fragments of glass that be could be compared with a sample of glass from the broken window of the kitchen at Orchard View.

Mr Norton then told Ms Ni Raifeartaigh, he found six small fragments of glass from the duvet cover and they matched the control samples from the kitchen window.

The jury also heard the sheet taken from the bedroom of Sylvia Shields had two small fragments of glass that matched the glass from the kitchen window at Orchard View.

Mr Norton told Ms Ni Raifeartaigh that the items were suspended on a stand alone, funnel type apparatus,a metre in depth, to be examined.

"The items would have been brushed down into a Petri dish, as fragments of the glass were very small and not visible to the human eye. The Petri dish is then examined for foreign material" said Mr Norton.

On August 27 1997, Mr Norton said he received the black pin stripped velvet jacket from Dr Thornton and carried out an examination for glass fragments.

The court heard that there were no glass fragments recovered from the pockets of the jacket but two glass fragments were recovered from the surface of the jacket.

When compared to the window at Orchard View, Mr Norton told Ms Ni Raifeartaigh they were different to the the control glass in the kitchen.

Mr Justice Carroll Moran told the jury of six men and five women that Mr Hartnett had indicated that matters had arisen and both him and Mr Grehan agree it would be wisest for them to come back at 2pm tomorrow.