DC Court Rules STRmix Source Code Inspection Is Available, But Unnecessary

WASHINGTONApril 11, 2019 /PRNewswire/ — Noting that STRmix™ – the sophisticated forensic software used to resolve mixed DNA profiles – “is not a secret product, as defendant characterizes it,” a Washington, DC Superior Court has denied a defense request to compel the prosecution in District of Columbia v. James Brandon (Case No. 2017 CF2 006160) to provide source code for STRmix™.

Associate Judge Robert A. Salerno ruled, “The source code for STRmix™ is proprietary. However, upon request, the owners of STRmix™ will make available to defense experts in criminal prosecutions where STRmix™ has been used to generate scientific evidence, the source code, a trial version of the software, developmental validation records, and the STRmix™ User’s Manual.”

Judge Salerno cited several precedents in which the courts have concluded that examination of the STRmix™ source code is not necessary to determine whether STRmix™ is reliable. This aligns with a great deal of expert opinion, including the FBI’s Scientific Working Group DNA Analysis Methods 2015 Guidelines.

Citing Virgin Islands v. Batch (No. ST-2015-CR-0000156), the court noted, “Despite not having the specifics of STRmix™ source code, the reliability of STRmix™ has been studied, validated, and declared suitable for DNA forensic testing by the FBI.”

Similarly, the trial court in U.S. v. Christensen (No. 17-cr-20037) stated, “Based on the testimony of a DNA forensic examiner explaining that there had been numerous validation studies by the FBI and developers, the growing number of laboratories using STRmix™, and the fact that STRmix™ had been repeatedly tested and widely accepted in the scientific community, the district court denied the motion to exclude the DNA evidence derived from the use of STRmix™ without the need to consider the program’s source code.”

“Defendant’s argument appears to be that examination of source code is necessary to assess the reliability … of STRmix™,” Judge Salerno concludes. “However, defendant does not explain why this is so, especially given the DFS [District of Columbia Department of Forensic Sciences’] internal validation studies, the [STRmix™] developer’s validation studies, and the other information available from the developer.”

He continues, “Apart from whether STRmix™ source code can be compelled from the government, it does not appear that review of STRmix™ source code is needed to make a Daubert challenge to DFS’s use of STRmix™ in this case.”

To date, STRmix™ has been used successfully in numerous U.S. court cases, including 28 successful admissibility hearings. Forty-four forensic labs in the U.S. are now using STRmix™, including federal agencies such as the FBI, state agencies like the recently added South Carolina Law Enforcement Division, and even private companies such as Bode Cellmark Forensics.

STRmix™ is also in various stages of installation, validation, and training in more than 60 other U.S. labs.

Internationally, STRmix™ has been used to interpret DNA evidence in more than 100,000 cases since 2012. It is currently used in all nine state and territory labs in Australia and New Zealand, as well as 11 forensic labs in EnglandScotlandIrelandFinlandDubai, and Canada.

STRmix™ was developed by John Buckleton, DSc, FRSNZ, and Jo-Anne Bright of the New Zealand Institute of Environmental Science and Research (ESR), and Duncan Taylor from Forensic Science South Australia (FSSA).

For more information about STRmix™ visit www.strmix.com.