In another admission of error in its handling of forensic evidence, the United States Federal Bureau of Investigation (FBI) has notified forensic labs that its analysts made mistakes in calculating the chances that DNA found on crime scene evidence matched particular people in thousands of cases.
A story published this past Saturday in the
reported that in May the bureau released a bulletin to crime labs across the country, stating that the errors—dating back as far as 1999—were due to clerical mistakes “in transcriptions of the genotypes and to limitations of the old technology software.” According to the
, the mistakes were discovered when the FBI decided to use new DNA testing kits that reportedly provide greater accuracy and retested DNA samples ran in previous investigations.
According to a public statement on Friday, the FBI said in that it found errors in three percent of the profiles it retested—around 33 profiles, specifically—which the bureau said falls within an internationally accepted range. The bureau stated that it doubts that the discrepancies will dramatically affect any cases, but attorneys and crime labs are demanding more information.
Stephen Mercer, chief of the forensic division of Maryland’s Office of the Public Defender, told the
, “The prediction that the errors are likely to have a nominal impact has to be assessed by the defense in the individual circumstances of each particular case.”
The FBI has submitted its findings for publication in the July issue of the
Journal of Forensic Sciences