• 11.02.15

The Problem With Using Secret Computer Code To Put People In Jail

As forensic science gets more and more high-tech, could bugs in the system put innocent people behind bars?

The Problem With Using Secret Computer Code To Put People In Jail
[Top Photo: Romas_Photo via Shutterstock]

When John Wakefield was convicted in a cold case murder in Schenectady County, New York earlier this year, the real winner–according to the local newspaper–wasn’t the victim’s family or the district attorney’s office. It was a DNA software company.


The software, from the Pennsylvania firm Cybergenetics, matched Wakefield’s DNA to the mix of DNA found on the victim’s body and the murder weapon. It was crucial to the jury’s verdict of life in prison.

DNA evidence has been used in criminal trials for decades. But the trial was the first in New York State to include DNA evidence from a new kind of advanced software. TrueAllele Casework, as the software is called, uses algorithms to analyze DNA in very low-level samples or in complex mixtures that contain the DNA of many people. It then teases out a percentage probability that the samples are a match. Human-centered methods that U.S. crime labs had been using for years would more often report “inconclusive” results for the same DNA samples.

The problem for Wakefield’s defense team–and for genetic privacy and transparency advocates–is that the proprietary software is a “black box.” They couldn’t question the program’s methods, like they could a human’s.

“They’re basically using secret code to come up with a DNA match statistic,” says Caitriona Fitzgerald, state policy coordinator for the Electronic Privacy Information Center, a group that recently filed a Freedom of Information Act request in six states to see the software’s code. “Secrecy of the algorithms used to determine guilt or innocence undermines faith in the criminal justice system,” their filing states.

Wakefield may have well committed the murder. But the stakes are high and that advocates fear that closed software that defense experts can’t inspect for themselves could cause errors in the future. In fact, this has already happened in Australia, where Queensland authorities said a minor “miscode” in similar software may have affected the DNA match likelihood in 60 cases involving three-person mixed DNA profiles.

In the U.S., TrueAllele has already survived at least six admissibility challenges in state courts, including in New York’s Wakefield case, and it has been validated by independent testing at forensics labs. And privacy advocates aren’t saying it shouldn’t be used at all. In fact, the software has already been used both to solve horrific crimes and exonerate innocent people. (In a case in 2014, TrueAllele was able to prove that a father had been raping his daughter for years. Because the father and daughter were related, the local crime lab couldn’t statistically distinguish between their DNA, but the higher-resolution software could.) Instead, they would like to see that the software is open for inspection by those accused.


“When that kind of evidence is presented in court, it influences the jury very strongly,” says Fitzgerald. “It’s this thing called the CSI effect. The jury sees DNA evidence introduced, and they think it must be correct.”

About the author

Jessica Leber is a staff editor and writer for Fast Company's Co.Exist. Previously, she was a business reporter for MIT’s Technology Review and an environmental reporter at ClimateWire.