Powerful DNA software used in hundreds of criminal cases faces new scrutiny
The software’s lack of scrutiny
But experts and civil rights advocates have long been concerned about the lack of scrutiny of the software. Their arguments may be gaining traction, as evidenced by the two rulings last month.
“Our justice system cannot permit convictions based on secret evidence,” wrote the Electronic Frontier Foundation and the American Civil Liberties Union of Pennsylvania in anamicus briefto the federal court. “There is a long history of junk science employed under the guise of technological advancement in criminal cases—and of public access to and analysis of such evidence as the means to its eventual invalidation.”
Frombite-mark pattern evidencetoblood-spatter analysis,and evenballistics testingandfingerprint matching—many forensic methods that were once commonplace in crime labs and courts have later been questioned or even totally debunked after facing outside scrutiny.
Life-or-death software programs—like those used in medical equipment or airplanes—must undergo independent validation and verification processes, but not so DNA software. There are few federal regulations about how police or crime labs introduce new technologies and methods into crime-solving. Every state has its own rules about how a new type of forensic technology gets approved for use, and judges tend to follow prior decisions when deciding whether or not to allow new scientific techniques into evidence.
Reviewing TrueAllele will likely be complicated—itsinventor estimates doing sowould take a person, reading 10 lines of code an hour, about eight and a half years to complete (which defense attorneys dispute)—and how to go about it has been another source of friction between prosecutors and defense attorneys.
Originally, defense teams in the two cases were surprised to learn their access to the source code would be restricted to a read-only iPad and that they would be allowed to use only a pen and paper to take notes. They have since lobbied for and won access to an electronic copy they can run and test themselves.
Though TrueAllele has never faced scrutiny like this before, two of its competitors have.
The competitors
When a federal judge of the U.S. District Court for the Southern District of New York ordered source-code access to New York City’s proprietary DNA analysis software Forensic Statistical Tool (FST) in 2016, the examinationrevealed a serious flawthat “tend[ed] to overestimate the likelihood of guilt.” The judge in that case eventually lifted the protective order on the software, and ProPublicaobtained the codeandpublished it on GitHub, allowing researchers and the general public to scrutinize it themselves.
The New York City Office of Chief Medical Examiner replaced FST with STRmix, a widely used competitor to TrueAllele. It so happens that the makers of STRmix havealso acknowledged software bugsthat affected 60 cases in Australia.
“Software errors are common and forensic software has no special immunity from the bugs and mistakes that plague software in other fields,” wrote Khasha Attaran, the assistant federal public defender representing Ellis, in an emailed statement. “Constitutional principles and fairness demand access because an accused must be allowed to examine and challenge the accuracy ofsoftware-generatedevidence relied on by the federal government.”
The federal prosecutors may appeal the decision to the U.S. Court of Appeals for the Third Circuit but haven’t indicated yet whether or not they will. The New Jersey case may head to the state’s Supreme Court. The U.S. Attorney’s office prosecuting the Ellis case for the Western District of Pennsylvania and the Hudson County Prosecutor’s Office, which brought the case in New Jersey, both declined to comment on ongoing cases, as did Mark Perlin, the founder of Cybergenetics and TrueAllele’s inventor.
This article wasoriginally published on The Markupand was republished under theCreative Commons Attribution-NonCommercial-NoDerivativeslicense.
