Mark Nash trial: No written lab-cleaning guide in 1997, jury told

A murder trial jury on Wednesday heard there were no written cleaning procedures for laboratories in 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 7th, 1997.

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

Forensic scientist Dr Maureen Smith was cross-examined by Mr Hugh Hartnett SC for the accused on Wednesday.

Last Thursday, the jury heard Dr Smith, who retired 10 months ago, worked as a forensic scientist for the last 35 years and was working in the biology and DNA section of Forensic Science Ireland (FSI), then the Forensic Science Lab, in 1997.

On Wednesday, Mr Hartnett put it to Dr Smith that in 1997/98, scientists would have needed something about the size of a 50 cent coin to extract DNA, which Dr Smith agreed with.

DNA advance

Mr Hartnett told the court that in 2009, “things become much more sensitive in relation to extracting” DNA and one could extract a profile from “material that is invisible to the naked eye” which was a “huge change”.

Dr Smith agreed with this.

Mr Hartnett asked Dr Smith about the cleaning procedures used for a lab in 1997.

“I don’t believe we had written procedures in 1997 but that didn’t mean we didn’t clean the labs,” replied Dr Smith.

“Why was there nothing in writing so that the people using the labs would know what to do?” Mr Hartnett asked Dr Smith.

“With the evolution of any lab, much more is written down now, then was then, there are more written records - in the past people were relying more on their training and word of mouth,” replied Dr Smith.

Prevention of contamination

Reading from a document entitled Guidelines on Prevention of Contamination from FSI, Mr Hartnett told the court there were six versions of this document since 2003.

“The possibility of exhibit contamination has to be considered at all stages, from receipt to analysis,” read Mr Hartnett.

“How does one guard against possible contamination as an exhibit is moved from A to B?” Mr Hartnett put it to Dr Smith.

“The items are packed,” replied Dr Smith.

"And sealed?" asked Dr Hartnett.

“They are now sealed when moving,” replied Dr Smith.

“That was not so in 1997?” asked Mr Hartnett. “That’s correct,” replied Dr Smith.

Mr Hartnett asked Dr Smith what her view was on the same room being used for the clothing of victims and suspects.

‘Benches cleaned’

“It is recommended they are not searched in the same room, but if it has to happen, benches are cleaned and time would lapse between one side of the case and the other,” replied Dr Smith.

Last Thursday, the jury of six men and five women heard a jacket belonging to the accused and heavily blood stained clothing and bedding found at the scene were examined in the same room at a laboratory, six weeks apart.

The trial continues.