Thursday, November 19, 2020
Alexander Jurenka (University of Davis School of Law) has posted A Forensic Breakthrough: Proteomic Analysis of Human Hair for Individuation Evidence (57 Crim. L. Bull. (2021, Forthcoming)) on SSRN. Here is the abstract:
Following a number of reports casting serious doubt on the validity of commonly used methods, the forensic sciences are in a state of crisis. Optical hair analysis for individuation has been shown to be particularly susceptible to erroneous findings. This error comes both in the form of incorrect identifications as well as examiners overstating the weight of optical hair analysis evidence. Absent DNA, there is currently no method available to forensic scientists to provide individuation evidence using a hair sample. Hair protein individuation (“HPI”) aims to fill in this crucial gap in the forensic sciences. HPI utilizes well-established scientific techniques including tandem mass spectrometry, which is already used heavily by forensic scientists for drug identification, to offer an objective, instrument-based analysis of the human hair proteome for individuation evidence. To date there is no legal scholarship concerning HPI, this article provides the first legal analysis of the admissibility of HPI. First, the article details the process of HPI, including literature review, and analyzes the technique for admissibility as evidence of individuation under the Federal Rules of Evidence and the Daubert standard. The article finds that HPI is built on a strong foundation of well-established scientific principles and therefor likely passes the requirement of foundational validity. Next, an examination of validity as applied finds that HPI is likely admissible under certain circumstances relating to the extent of the research conducted to date. Specifically, HPI in its current state may be admissible evidence if the examiner has cranial hair of European origin in sufficient quantity to perform the technique in duplicate. The article concludes with recommendations for future research and collaborations to expand the admissibility of HPI. HPI is a rapidly growing field of study and its admissibility is likely to expand with further research. Forensic hair analysis is undergoing a paradigm shift and HPI stands ready to replace outdated methods, judges and forensic scientists alike should stay informed of its progression.