The FBI admits that up to 95 percent of their testimony regarding hair comparison overstated the likelihood of hair matches in testimony. The last thirty years of hair analysis by the FBI has been called into question, and the potentially impacted cases go back decades. The FBI laboratory’s hair comparison unit conducted 2,500 cases using a process that has been found to be more subjective than scientific. Hair and bite-mark forensics rely on a process of matching patterns, which is not a definitive technique like DNA.
In a three year investigation, it has been found that questionable methodology in the hair examination process has led FBI examiners to give unreliable testimony in 257 of the 268 trials that have so far been re-examined. The National Association of Criminal Defense Lawyers (NACDL) and the Innocence project are partnering with the government to review the cases in question
Over 1,200 cases remain outstanding that need to be reevaluated because hair evidence was used during trial. Even though the FBI has been questioning the validity of hair analysis for ever a decade, finding an 11 percent error rate when compared to DNA as far back as 2002, convictions besed on accepted scientific evidence is particularly difficult to challenge.
Members of Congress urged the FBI to identify why such egregious error occurred, and to make the changes necessary to stop false convictions in the future. The potential impact is far reaching. 46 states and the District of Columbia had cases affected by the FBI hair analysis practices. DC was the first jurisdiction to review all cases affected by the faulty hair analysis. Five of seven convicted had their convictions overturned, but only after serving between 20 and 30 years for rape or murder.
Juries can be misled by seeming expert witnesses. A seasoned criminal defense attorney can help protect you from the risk of false convictions.
WashingtonPost.com, “FBI admits flaws in hair analysis over decades,” Spencer S. Hsu, 18 April 2015