AS Shirley McKie's father I was interested in Susan Swarbrick's interview with Tom Nelson, director of Forensics Services at the Scottish Police Authority ("Forensics for Dummies - I admit it was a great read", The Herald, October 14).

In 2011 Mr Nelson generously took the lead in apologising publicly to Shirley for the failures of his fingerprint experts and when further apologies quickly followed from the Secretary for Justice, Lord Advocate and, the then Strathclyde Chief Constable, Steven House, our family was able to finally let go and Shirley could start rebuilding her life.

Welcome as these apologies were, however, and much as I respect Mr Nelson, it would be wrong of your readers to believe that all is well in the field of expert evidence. Lessons have still not been learned.

In the current BBC Scotland TV series, Crime Scenes Scotland: Forensics Squad, which legitimately highlights some of the successful work of Mr Nelson's experts, renowned criminal defence lawyer Donald Findlay QC, who successfully defended my daughter in her 1999 trial, warns "DNA and its significance has grossly (been) overstated by the prosecuting authorities and certainly over-valued by the public at large". He observes that unlike in the fictional world of television's CSI, forensic experts are not able to neatly wrap up the case, "within 47 minutes and 8 seconds. Unfortunately life doesn't work that way."

Those of your readers who doubt Donald Findlay's warnings about forensic evidence only have to Google the name of Willie Gage, who I and many others believe was wrongly convicted of murder in 2002, to find out that here in Scotland many of the prosecutorial authorities, lawyers and judges continue to act as if expert evidence was indeed infallible and the fiction of TV was mirrored in real life. There is a consistent failure to test this evidence effectively and take account of the thousands of cases across the world where erroneous expert evidence has condemned people to prison or even death.

This is the reality that bears tragic testimony to the fact that real life does not mirror the fictional infallibility of CSI or the airbrushed "reality" of the BBC's Crime Scenes Scotland: Forensics Squad.

Iain A J McKie,

27 Donnini Court.

South Beach Road.