Newspaper article Pittsburgh Post-Gazette (Pittsburgh, PA)

Defense Tries New Tack to Fight DNA Evidence in Homicide Case

Newspaper article Pittsburgh Post-Gazette (Pittsburgh, PA)

Defense Tries New Tack to Fight DNA Evidence in Homicide Case

Article excerpt

Defense attorneys for Michael Robinson have tried everything to challenge DNA evidence against their client for a 2013 double homicide in Duquesne.

First they asked Allegheny County Common Pleas Court to order Cybergentics' founder Mark Perlin to turn over the source code for his computer program, TrueAllele, which links Mr. Robinson to a black bandanna found near the crime scene.

They argued that Mr. Robinson has a right to confront his accuser at trial, and without knowing what the computer program does, they can't properly challenge the evidence.

But they were rejected by Judge Jill E. Rangos and took the issue to the state Superior Court. When that failed, they asked the state Supreme Court for relief.

They were rejected there, too, and have now filed a new motion alleging that TrueAllele is "novel" and does not have "general acceptance in the scientific community."

Judge Rangos will listen to the argument today to decide whether Mr. Robinson is entitled to have a hearing on that issue.

Defense attorneys Ken Haber and Noah Geary based their most recent motion on a September report from the President's Council of Advisors on Science and Technology, a commission of scientists and engineers appointed by President Barack Obama to explore the validity of forensic evidence in the aftermath of a 2009 report that was highly critical of a number of fields of forensic science.

The new report, "Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods," examines a number of forensic sciences, including bitemark, fingerprint, hair and firearms analysis.

It also evaluated DNA analysis in samples involving a single-source and mixtures.

The report spends about seven of its 160 pages addressing complex DNA mixtures - like those that exist in the Robinson case - and notes that probabilistic genotyping software programs like TrueAllele "clearly represent a major improvement over purely subjective interpretation."

But it continues, "they still require careful scrutiny to determine (1) whether the methods are scientifically valid, including defining the limitations on their reliability (that is, the circumstances in which they may yield unreliable results) and (2) whether the software correctly implements the methods. This is particularly important because the programs employ different mathematical algorithms and can yield different results for the same mixture profile."

The report recommends that the programs be studied by multiple groups not associated with the software developers.

In its conclusion, the commission wrote that two most widely used programs, STRMix and TrueAllele, "appear to be reliable within a certain range, based on the available evidence and the inherent difficulty of the problem," and that they have "foundational validity" in mixtures of three people, provided the minor contributor makes up at least 20 percent of the DNA in the sample. …

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