There are few things more convincing to a jury than scientific evidence presented by expert witnesses called by the state in a criminal case. Sometimes, however, the so-called science used by prosecutors isn't science at all.
Many Texas defendants have been convicted when fraudulent or invented forensic techniques were presented as scientific truth at trial. Others have gone to prison as a result of genuine science being twisted into false accusations of guilt. From the Houston Crime Lab disaster to the discredited testimony of experts like Ralph Erdmann and Fred Zain, Texas leads the nation in scandal over this problem. The Cameron Todd Willingham case, in which discredited arson science was used to get a conviction, is only one of many examples of the use of this kind of evidence.Just last year, the Innocence Project of Texas exposed the work of Keith Pikett, a Fort Bend County Sheriff's deputy who made use of "dog-scent lineups" to link suspects to evidence retrieved from crime scenes. The Innocence Project report [ed note: see the pdf here], entitled Dog Scent Lineups: A Junk Science Injustice, called attention to the numerous wrongful accusations and convictions that resulted from this form of junk science. Even though the self-trained deputy did not have a scientific background, he was allowed time and time again to testify in criminal trials about the alleged science behind his lineup procedures. Pikett's expert testimony was all junk and no science — and it was used repeatedly by prosecutors. In an encouraging move, the Texas Court of Criminal Appeals recently reversed a case based on Pikett's testimony. That move aside, prosecutors are still allowed to use charlatans like Pikett in Texas courtrooms.
The technique of using phony experts, unscientific evidence or just plain fraud dressed up as expert testimony is known as the use of junk science. It is being employed to get convictions in courtrooms all over the state to this day.
Fortunately, there are solutions to this problem. Innocent citizens who have been convicted in the past because of junk science need to have a fair day in court to prove that they were wrongfully convicted. Forensic labs need to be separated from law-enforcement agencies and made fully accountable to the scientific community. Trial procedures need to be improved so that innocent citizens will not be victimized by junk science in the future.