Mark Nash pleads not guilty to murder as trial hears evidence

This report is a localnews.ie summary based on public court reporting and records; sources are listed below.

Mark Nash has pleaded not guilty to the murder of Sylvia Shields and Mary Callanan at the Central Criminal Court, with evidence heard on 18 March 2015. The women were living in sheltered accommodation attached to St Brendan’s Hospital in Grangegorman. Forensic scientist Dr Maureen Smith told the trial there were no written laboratory cleaning procedures in 1997, although laboratories were cleaned. She also agreed that DNA extraction had become more sensitive by 2009. The trial heard that clothing belonging to Nash and blood-stained clothing and bedding from the scene were examined in the same room six weeks apart. The trial was continuing.