TV-shows like CSI and Bones, have seared in the public
consciousness the image of the faultless crime fighting forensic
scientist and infallibility of DNA evidence.
But the reality is that DNA evidence is not what many believe it
to be – it is, in fact, susceptible to human errors including
botched testing and to
bias or even
misconduct by testers and those issuing 'expert
certificates' – who are often current or former police
officers – and there have been
numerous cases of ostensibly indisputable DNA evidence
falsely connecting innocent persons to crimes.
as well as misinterpretation by juries, judges and lawyers
alike.
A common problem is the "prosecutor's fallacy",
which is an error of interpretation that routinely occurs DNA
evidence is presented in court. It is a situation which presents a
danger of unfair prejudice against defendants, who may be convicted
on a misconception that the evidence is more powerful and probative
than it really is.
