Courts / Dublin / Report

Exhibits at lab found to contain DNA profiles of staff who never had any contact with them, trial hears

Date
2015-03-18

Stage
Trial

Primary locality
Dublin

County
Dublin

Summary

In a 2015 murder trial, the jury heard that forensic exhibits examined at Forensic Science Ireland contained DNA profiles of laboratory staff who had never handled the items. Mark Nash, 42, pleaded not guilty to the murders of Sylvia Shields, 60, and Mary Callanan, 61, committed in March 1997. Dr Maureen Smith, a retired forensic scientist with 35 years of experience, explained that contamination events have been recorded since 2011, when the lab began keeping logs. She noted that DNA from staff could appear on exhibits through skin cells, hair, or other transfer, even when protective clothing was worn. The court discussed cleaning protocols, the use of sealed bags, glove changes, and the recommendation to avoid using the same room for victim and suspect items. The trial continues.

Who, what, where, when and why

What: Report matter: Exhibits at lab found to contain DNA profiles of staff who never had any contact with them, trial hears. Charges or matters: the murder of Sylvia Shields (60) and Mary Callanan (61) between March 6 and March 7, 1997. Procedural stage: trial

When:

March 6 Hearing Or Sentence
March 7, 1997 Hearing Or Sentence
April 2012 Other
2015-03-18 Publication

Why: "Before you handle the item inside because of risk of anything, so you don't transfer anything from outside, again I would see it as a remote possibility but this covers all eventualities," replied Dr Smith. CNI source report