Defense attorneys around the nation are questioning the legitimacy of the DNA interpretation software, TrueAllele, which is used by law enforcement in at least six states to assist in separating and identifying DNA evidence.
Attorneys are interested in how TrueAllele’s software works to ensure that clients aren’t wrongfully linked to crimes based on the system’s interpretation of their DNA.
According to DNA experts, DNA from multiple people can intermix on anything including gun grips, clothing and victims, The Wall Street Journal reports. These mixtures can be complex, making it difficult for labs to sort out, resulting in inconclusive evidence more than half of the time.
Only seven out of every 100 crime labs nationwide were able to correctly separate a complex DNA mixture, according to a study by the Commerce Department.
To protect their clients from incorrect DNA matches, attorneys such as Noah Geary, are challenging TrueAllele’s reliability and methodology. Geary is the lawyer for Michael Robinson, who TrueAllele linked to the fatal shooting of two men in Pennsylvania after a crime lab deemed DNA from the evidence provided was too complex to analyze.
A judge denied Geary’s request to review TrueAllele’s codes, and it is unclear whether the defense will file an appeal. Robinson could be sentenced to death as a result of these charges.
The developer of TrueAllele, Mark Perlin, continues to refuse requests to review the system’s source code, but is offering defense experts guided tests on a limited set of data.
Issues with TrueAllele aren’t the only doubts regarding the reliability of forensic methods recently. Defense attorneys and experts have also faced problems with flawed hair forensics and bite-mark evidence.