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Technology Used by DNA Expert Witnesses Faces Scrutiny from Defense Attorneys

Law-enforcement and defense attorneys in Pennsylvania have engaged in a legal battle over technology used by DNA expert witnesses to narrow down suspects and identify criminal defendants.  Use of a computer program which unravels DNA inter-mixed at crime scenes has been disputed by defense lawyers who do not have access to its programming source code.

DNA Experts in Pennsylvania use High Tech Program

Over the last few years technology has emerged which allows law-enforcement officials to parse through mixed DNA samples taken from crime scenes in order to positively identify a single suspect.  TrueAllele, developed by the Pittsburgh-based company Cybergenetics, is able to infer a genetic profile from DNA and match it with large databases in order to provide police and prosecutors with positive matches.  According to the TrueAllele website, the technology reduces the chances of misidentification, operates without bias against certain suspects, and meets all legal and scientific guidelines for reliability.

The software is billed as a DNA identification tool for use by police investigating sexual assault, homicide, property crimes, and mass disasters.  In each case the TrueAllele software is able to single out “major and minor contributors” to the incident with the goal of assisting law-enforcement in identifying, arresting, and prosecuting parties responsible for criminal activity.  TrueAllele has been widely used in at least six states across the country including New York and Pennsylvania, but recently defense attorneys have pushed back against the software because expert witnesses who use it are unable to provide details about how the program works.

TrueAllele DNA Identification Software Challenged by Defense Attorneys

Defense attorneys who have been involved in cases where TrueAllele was used to connect defendants to a crime argue that secrecy surrounding the software combined with its impact on jurors violates suspect’s constitutional right to be considered innocent until proven guilty.  Citing a phenomenon known as the “CSI effect” concerned defense attorneys point out jurors not only expect scientific evidence, but place heavy reliance on it when making final verdict decisions.  The impact of DNA expert witnesses using TrueAllele on trials is significant, and with the software’s creators refusing to provide defense attorneys with the source code some attorneys questioning the legitimacy of the program’s use in criminal cases.

According to TrueAllele creator Mark Perlin, the program’s source code is a protected trade secret, but defense attorneys should be satisfied with its validity because of the software’s repeated use in trials to both identify guilty subjects and exculpate innocent ones.  Additionally TrueAllele has survived intense peer-review scrutiny by top DNA and computer program experts who attest to the software’s ability at accurately identifying DNA matches when crime scenes contain samples which make identifying one individual difficult.

Defense attorneys are not convinced, however, and argue the risk of miscodes or inaccuracies in TrueAllele’s source code can result in false convictions of innocent defendants.  Without access to the underlying code in a program DNA expert witnesses are citing to positively make matches that jurors will heavily rely on in their verdict decision, defendants arguably are not given a fair opportunity to challenge the evidence presented against them.

DNA Expert Witness Software Faces Legal Challenge

Defense attorneys for a man accused of murder in Pennsylvania have challenged the admissibility of TrueAllele evidence presented by a DNA expert witness by arguing the validity and methodology of the measure cannot be verified without access to the underlying source code.  Suspicion surrounding TrueAllele is driven by an announcement by the FBI in May that work done by forensic expert witnesses working for the agency on thousands of cases may be inaccurate due to faulty DNA identification software.  With the integrity of thousands of convictions at risk due to errors in DNA matching, defense attorneys are understandably suspicious of a software program with source code they cannot independently verify.

Despite the arguments against the use of DNA experts using TrueAllele, the software has been accepted in a number of criminal trials as reliable and scientifically valid evidence for expert witnesses to use when explaining forensic analysis to jurors.  TrueAllele has a short history, but its gaining acceptance indicates the software has been vetted more thoroughly than the programs which created errors for FBI expert witnesses.  Whether or not defense attorneys gain access to the source code, the use of TrueAllele by DNA expert witnesses seems likely to expand as trials increasingly rely on forensic analysis for reliable evidence.