In a recent decision, Texas Judge David Wahlberg ruled not to admit DNA evidence in the murder trial of University of Texas freshman Haruka Weiser.


During the pre-trial hearing, Judge Wahlberg said that he was dismissing the DNA results because the forensic scientist in the case did not follow the laboratory’s standard operating procedure.   The defense attorney in the case, Darla Davis, made a point of saying that this was “…not a ruling on the use of STRmix™ from the judge.”  The validity of STRmix™ was never argued in court.  Judge Wahlberg is quoted as stating “it turns out we don’t get to those issues in this case at this time.”


In short, the issue in this case was not with STRmix™.  STRmix™ has been used successfully in numerous U.S. court cases – including two recent Florida cases and a murder case in Brooklyn – as well as in thousands of cases internationally. There have also been at least 13 successful admissibility hearings in the U.S. for STRmix™.


Thirty-two U.S. labs now routinely use STRmix™ in resolving DNA profiles. This includes everything from federal agencies such as the ATF and the FBI to state and local agencies. STRmix™ is also in various stages of installation, validation, and training in 56 other U.S. labs.  In addition STRmix™ is in casework use by laboratories in Australia, England, Scotland, the Republic of Ireland, Canada, and New Zealand.


Moreover, the FBI’s internal validation of STRmix™ found that STRmix™ offers numerous advantages over historical methods of DNA profile analysis, has greater statistical power for estimating evidentiary weight, and is sufficiently robust for implementation in forensic laboratories [i].

[i] T.R. Moretti, R.S. Just, S.C. Kehl, L.E. Willis, J.S. Buckleton, J.-A. Bright, D.A. Taylor, Internal validation of STRmix™ for the interpretation of single source and mixed DNA profiles.  Forensic Science International: Genetics, 2017.  29:126-144.


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