Courts / Dublin / Report

Mark Nash trial jury hear of procedures at forensic lab

Date
2015-03-20
Stage
Trial
Primary locality
Dublin
County
Dublin

Summary

In a 2015 murder trial, forensic scientist Dr. Linda Williams testified that a 2013 contamination incident at Forensic Science Ireland prompted a change in procedure: the outside of exhibit bags began to be wiped down. Williams explained that DNA profiles matching Sylvia Shields and Mary Callanan were derived from threads on the accused Mark Nash's jacket and a small particle in a seam of a black velvet jacket, respectively. She could not specify the exact source of the DNA or the particle. The court heard that in 2013, two unrelated cases were processed on the same surface, leading to contamination. Dr. Geraldine O'Donnell, former quality manager and now Director of DNA, described the lab's quality system, the introduction of bench logs in 2011, and the formal logging of contamination events, noting 14 in 2011, 22 in 2012, and 31 in 2013. The prosecution's case was concluded, and the judge postponed the jury's return to Tuesday. Mark Nash pleaded not guilty.

Who, what, where, when and why

What: Report matter: Mark Nash trial jury hear of procedures at forensic lab. Charges or matters: the murder of Sylvia Shields (60) and Mary Callanan (61) between March 6 and March 7, 1997. Procedural stage: trial

When:

Why: "Just because you don't have bench logs, doesn't mean you can't track a case," said Dr O'Donnell. CNI source report

Case subjects

Mark Nash

Defendant

Charges: the murder of Sylvia Shields (60) and Mary Callanan (61) between March 6 and March 7, 1997 (Alleged Or Contested)

Plea: Not guilty

Places mentioned

Incident
  • Prussia Street
  • Clonliffe Road
Secondary Mention
Court Venue
  • Central Criminal Court
Facility
  • St Brendan's Hospital

Topics

Stage Trial Violent Crime

Related court reports

Read the original CNI report

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