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Nearly 5,000 Austin Convictions in Limbo due to DNA Lab Errors, But Relief for the Wrongfully Imprisoned Still a Long Ways Off

Chris Perri

Photograph by University of Michigan DNA Lab

Photograph by University of Michigan DNA Lab

The Austin American-Statesman has thoroughly covered the fallout from the Austin Police Department’s DNA lab closure, but if you haven’t been following the news closely, it’s difficult to find one article that provides the overall picture of what’s going on with the DNA issues in Travis County. Below, I’ve summarized the recent Austin DNA Lab scandal, along with providing a legal perspective on how these revelations might affect people who were convicted on the basis of false DNA evidence.

Recalculations vs. Retesting

In the summer of 2015, the FBI announced that errors in its database might have caused nationwide laboratory miscalculations of the probability that DNA found in evidentiary mixtures matched particular defendants’ known DNA profiles. Here is a blog post I wrote on the subject.

The important takeaway is that while the FBI’s database error affected cases nationwide, it only applied to DNA mixtures, which is a type of sample that contains two or more people’s DNA. If DNA mixture evidence contributed to a defendant’s conviction, then the defendant can request a recalculation of the probability that the mixture contained the defendant’s known DNA profile. Such recalculations do NOT involve any re-testing, as the lab simply uses the corrected database protocols to recalculate the probability of a match. The FBI database issues do not implicate the reliability of the actual testing conducted by the various forensic laboratories.

While government agencies argued that the recalculations would not materially affect any pending cases, these assurances became less credible when recalculations in a Galveston murder case drastically reduced the probability that the defendant was the perpetrator.

Meanwhile, the DNA retesting issue rocked the Austin Police Department (APD) last summer, and it could affect up to 5000 past convictions. The chaos began when the Texas Forensic Science Commission conducted an audit of APD’s DNA Laboratory last spring, and the Commission discovered a host of unreliable scientific practices pervading the lab. Among the highlights:

1.     Improper Stochastic Threshold: DNA labs must adopt guidelines to determine whether their interpretation of each DNA sample is scientifically reliable. The stochastic threshold is the point at which a scientist can reliably interpret DNA in a manner that’s not muddled by random effects, such as allele dropout. At APD’s lab, the scientists used a quantitative baseline (as opposed to a qualitative one) as its stochastic threshold, despite the fact that no peer-reviewed journal had ever accepted such a quant-based threshold. Without a valid stochastic threshold, the lab cannot be certain whether its testing results were merely a product of randomness, as opposed to sound scientific process. Because an improper protocol was used at the very beginning stages of all DNA testing, any of the final interpretative results are unreliable. Garbage in, garbage out.

2.     Suspect or Victim-Driven Testing: Sound scientific method requires that scientists select an unknown sample’s comparison loci (the particular segment of DNA material that will later be compared to the known DNA profiles) without knowledge of which comparison loci are clearest on the known DNA profiles. However, APD’s “scientists” were essentially cheating, as they used the known DNA profiles of suspects and victims in order to determine which loci to examine in the unknown samples. This practice created a bias towards finding a match.

3.     Unclear Use of Protocol Deviation: Lab technicians occasionally deviated from clear technical guidelines when it suited the particular needs of a case. Part of the problem stems from APD’s scientists not remaining independent from the investigative team, as the scientists often felt pressure from investigators to return favorable results. This collusion is one of the main reasons why I’ve advocated an independent lab, and the Travis County judges agreed in a proclamation last December.

4.     Contamination: In one egregious example of incompetence, the Forensic Science Commission observed carry-over contamination between the DNA on a victim’s vaginal swab and the DNA on a suspect’s penile swab, despite the fact that this suspect was later determined to be unrelated to the offense. It took re-testing by a different laboratory before this suspect was cleared for an offense he did not commit.

After the Commission’s report, there was also a revelation that a freezer housing hundreds of DNA samples broke down last spring for eight days, leaving officials uncertain whether evidentiary samples had been damaged.

Somehow, despite these systemic problems at APD’s DNA lab, it received annual accreditations for over a decade. A Statesman article revealed that the accrediting body "did not test if a lab’s scientific processes were appropriate for analyses." That seems like a pretty huge oversight in the accreditation process.

The Fallout

Since the revelation of these monumental problems at APD’s DNA Lab, it has closed down and the testing on all pending cases has been sent to independent labs. However, the problem remains of what to do about the convictions from 2005-2016 that were based on faulty DNA testing. Estimates on the number of cases that need to be reviewed range from 3,600 to 5,000.

The Travis County Commissioners and City Council have been considering options for implementing a materiality review to determine which cases need to have the DNA evidence retested, with cost estimates for this review ranging from $6 million to $14 million. However, as of today, the bureaucrats haven’t made a decision, and they appear to be leaning towards the least costly option. I’ve argued that at a minimum, this materiality review must be independent from the Travis County District Attorney’s Office, which has a conflict of interest by virtue of securing the convictions that are under review.

The critical point right now is that the essential independent materiality review of the thousands of cases hasn’t yet begun, and there’s no telling how long it will take to create an independent commission to conduct the review. Even then, a materiality review will only identify the cases in which DNA evidence was a material contributor to a conviction, and at that point, DNA re-testing will be ordered. Defendants will then have to wait for the DNA re-testing to be completed before they know whether they’re entitled to a new trial. And if they are entitled to a new trial, the defendants will have to wait even more time while an application for writ of habeas corpus circulates through the trial court and the Court of Criminal Appeals.

Given the lack of agreement in political circles about how best to conduct the review and the time lag to implement any proposed solutions, there’s no relief in sight for defendants waiting on Travis County to solve this mess.

How We Can Help

Chris Perri Law has over a decade of experience in reviewing post-conviction cases. If you or a loved one suffered from a conviction involving DNA evidence that was tested by the Austin Police Department, contact our firm to review the case. If your case was not in Austin but involved DNA mixtures, contact our firm about requesting a re-calculation of the probability that the DNA mixture matched the defendant. We advocate for our clients from the beginning stages of the process (DNA materiality review) through the final litigation of the writ of habeas corpus in order to ensure that wrongfully convicted people are set free.