Forensic science, reliability and scientific validity: Advice from America

In this article we review an important report produced by the US President’s Council of Advisors on Science and Technology, Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods (the PCAST report).2 The PCAST report builds on an earlier report prepared by the National Research Council, Strengthening Forensic Science in the United States: A Path Forward published in 2009 (the NRC report).3 These reports are focused on the organisation, funding and practice of the forensic sciences in the US. In their deliberate and unflinching concern with probative value, particularly the validity and reliability of procedures used by forensic scientists and the way opinions are expressed in expert reports and testimony, both have application to England and Wales. Both reports speak directly to forensic scientists, law enforcement, lawyers and courts. Forensic scientists, advocates, judges and legislators must respond to these criticisms and recommendations if we hope to place the forensic sciences on firm scientific foundations.4