Take some time (or more than one visit to get through the information) and follow this link (Forensic Testimony) to a greater understanding on why credibility for some forensic experts is waning or finally being extinguished. The chart posted above will gain added meaning.
The first link goes to the U of Virginia Law website authored by law prof Brandon Garrett. This website is an expanded attribution to his 2011 Harvard Press book “Convicting the Innocent: Where Criminal Prosecutions Go Wrong.” The site has a wealth of cases in the library collection and contains scanned transcripts from the trials of people exonerated by post-conviction DNA testing who had testimony by forensic analysts at their original criminal convictions (look here)
A short comment
The subject of error rates and validity testing for “police sciences” of serology, hair, bite mark, fingerprints, voice id, and shoe print experts testifying for the prosecution has been around for years. The combination of these types of forensic testimony when coupled with DNA profiling has been alarming for the public and the news media. The mistakes in forensic testimony are being slowly (if at all) addressed by the forensic organizations whose members came up short in court after DNA exonerated the defendants. The recent FBI/NACDL/Innocent Project task force on misguided hair comparison analysis may be a precursor or a litmus test for other “police examiners” lacking the moral fiber to follow their own Codes of Ethics.