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DNA tests for criminal cases across Texas are getting second looks from labs because one of the largest DNA test manufacturers globally told customers about issues with some tests distributed from February 2024 to October 2024.
Officials at Qiagen, the multi-billion-dollar maker of DNA tests, alerted customers in Texas and Virginia that they received complaints that their EZ1&2 Investigator Kits were extracting less DNA than expected.
Complaints reported that some tests incorrectly represented that not enough DNA existed to test, and others represented samples that had multiple people’s DNA present as fewer or just one person’s genetic material.
Assessing the scope of the impact of affected tests was difficult to determine because Qiagen has not disclosed the total number of tests or where affected tests may have been sent.
“We have received fewer than 10 complaints nationwide on this matter, and the number of kits involved has been well below 1% of annual manufacturing,” said John Gilardi, vice president and head of corporate communications, in a statement.
But Gilardi declined to say how many kits the company produces in a year. The company is one of the biggest providers in the world.
“It’s a big deal,” said Peter Stout, president of the Houston Forensic Science Center (HFSC). “This is a product that almost everybody uses … all across the U.S., all across the world.”
Qiagen declined to give TPR an interview because it was a public holiday in Europe but responded to some questions in writing. Officials said the tests met their internal quality control measures, and while the company recovered stock from labs, it was not a recall.
The results, however, are leading forensic scientists in those labs to question if results are scientifically reliable.
The Houston Forensic Science Center disclosed the intermittent problems it and other labs were having at an April 11 meeting of the Texas Forensic Science Commission. Texas is one of few states with a public agency overseeing how forensic science is used in courts.
HFSC discovered the problems with the tests and brought it to the company’s attention last year. Stout told the commission that the HFSC had several conversations with the company and flew to the labs and factories in Germany.
In a letter to clients dated April 1, Qiagen said it made production changes at its factory to address the issue in October 2024 after alerting customers of the complaints.
“Based on the data available, there is no indication of a broader or systemic issue,” said the letter.
The tests used for dried blood, bone, semen, saliva, and trace DNA are largely for criminal prosecutions, meaning the stakes are high when errors occur.
“Texas is a death penalty state, many others are. Justice is a matter of life and death,” said Michael Kessler, principal at Kessler Forensic Solutions, a company that consults on DNA analysis in trials.
The affected tests at times fail to always produce a DNA profile when it is present.
“We run the risk of missing a profile that could be potentially exonerating. We also run the risk of missing a profile that could be of importance for an investigation. So basically, you could think of the sexual assault kit that we don't get the profile of. The potential offender … they go un-arrested,” Stout said.
The Texas Department of Public Safety confirmed that its Austin laboratory uses the tests, and it was reviewing 700 cases for next steps. The HFSC confirmed it will likely review hundreds more cases. But the impacts could be far greater nationwide, according to experts.
“I would think if they wanted to have an abundance of caution, they could go back now to case work samples, where they got ‘no’ results,” said Dan Krane, professor at Wright University and consultant for forensic testing.
That is if there is now enough material to test. “A lot of these evidence samples are going to be low quantity. Swabs of gun cartridges, for instance, and they had one crack at it, and you just can't go back,” he added.
The costs of retesting will be incurred by the labs.
The HFSC discovered the testing irregularities through its own quality assurance program. When officials reviewed the data, they saw a jump in the number of samples between June and August 2024 they sent out to contract labs coming back with so-called “unintuitive results” rising from about two samples to 45.
“That's a 14% rate,” Stout told the Texas Forensic Science Commission. “That stuck out.”
HFSC noted areas of improvement for Qiagen going forward in its presentation, including testing more of the cartridges. It found Qiagen tested only 36 cartridges per lot with an average size of 83,000. Statistically, it should have checked 235 cartridges for a 95% confidence rate, the HFSC presentation added.
What makes any analysis difficult is that Qiagen declined to disclose to TPR how big its lot sizes were.
Qiagen explained that it conducted a full investigation and that all the kits passed all the company’s quality control standards.
“I think what's more concerning is the length of time over which this problem was occurring, the fact that the quality control program for the manufacturer did not catch the issue,” said Elizabeth Daniel Vasquez, a former public defender who now consults for criminal defense teams on forensic science.
The culprit for the issues was tentatively identified as the pH balance of one of the chemicals — the MTL buffer — used in the tests. HFSC noted other issues with cartridges — the long rectangular devices designed with numerous wells to hold components of the DNA testing process like chemicals. Upon visual inspection, scientists found a magnetic bead and specific chemicals in the wrong wells.
It wasn’t clear how many labs across Texas or nationally received the affected tests, but among them was the Department of Public Safety’s offices in Austin as well as private testing labs Bode, based in Virginia, and Signature Science, based in Austin. Signature Science is a subsidiary of San Antonio’s Southwest Research Institute.
Two letters to labs reviewed by TPR showed that Signature Science and others were contacted by Qiagen in October 2024 about the issues.
In a letter dated April 23, Signature Science told its clients that Qiagen failed to identify all affected lots and that its lab’s DNA extraction work was also impacted this year.
“Signature Science believes any sample extracted between June 24, 2024, through February 28, 2025, that utilized EZ1&2 DNA Investigator reagent cartridge lots 178019172, 178026981, 178029201, or 178032040 may be impacted by this issue.,” said Samantha Wandzek, technical leader for Signature Science, in a letter to clients obtained by TPR.
Signature Science did not respond to TPR’s requests for comment.
In another letter obtained by TPR, Bode labs said it had internally tested the affected lots and “it is unlikely that samples processed at Bode have been affected by this sporadic issue.”
Qiagen said it has been responsive to labs’ concerns. “In every case we’ve worked directly with the lab to investigate the concern, perform follow-up testing and provide full support,” Gilardi wrote in an email.
But those assurances may not be enough for defense attorneys.
“We're going to see a ton of cases where the impact of this is going to be directly clear,” said Daniel Vasquez. “I think more likely what we'll see is a whole lot of lack of evidence that nobody realizes was lost in the process.”
