Grits for Breakfast 10/25/2019
For some time, Grits has been skeptical whether DNA-mixture software would hold up to "Daubert" scrutiny if judges were to directly evaluate it. In 2015, this blog reluctantly broke the story in Texas about errors and uncertainties regarding how to evaluate DNA mixture evidence. (They were being openly discussed by the Forensic Science Commission and the Court of Criminal Appeals' Criminal Justice Integrity Unit when I worked for the Innocence Project of Texas, but reporters weren't covering the complicated, math-heavy story.) After that, I've followed the issue from afar even after I stopped tracking forensics in any professional capacity.
STR-Mix is one of a handful of companies selling their product as a solution to the conundrum of how to evaluate DNA mixture evidence. Now, a federal district judge in Michigan, Janet Neff, after an exhaustive review of the science, has ruled directly on the Daubert-based admissibility questions surrounding this product that Texas courts punted on. In particular, Judge Neff ruled in favor of defendant David Gissantaner, concluding that
The DNA evidence sought to be admitted in this case—in essence, that it is 49 million times more likely if Daniel Gissantaner is a contributor to the DNA on the gun than if he is not— is not really evidence at all. It is a combination of forensic DNA techniques, mathematical theory, statistical methods (including Monte Carlo-Markov Chain modeling, as in the Monte Carlo gambling venue), decisional theory, computer algorithms, interpretation, and subjective opinions that cannot in the circumstances of this case be said to be a reliable sum of its parts. Our system of justice requires more.
More:
https://gritsforbreakfast.blogspot.com/2019/10/dna-mixture-software-widely-used-in.html
