Bulletin: Texas: Travis County District Attorney Rosemary Lehmberg says hundreds of criminal cases will be reviewed after learning of scientific concerns with the way examiners analyze evidence that includes genetic material from multiple people - and that her office also discovered an issue with the database it uses to calculate DNA statistics, which are presented in court as probabilities that a given sample included the DNA of a certain person. Lehmberg says her office is unsure how many Travis County cases are affected but says it is working to identify them and notify the parties involved. " “Just to be on the safe side, they are not going to count all the data they can count,” said Rob Kepple, the executive director of the Texas District and County Attorney’s Association. The old testing could have determined that there was a probability that someone’s DNA was included in an evidence sample, but the new testing could show that scientists can’t determine whether someone’s DNA was included, Kepple said. “That’s important for a defendant to know.” Such disclosures are important as labs test smaller and smaller traces of DNA found on objects, such as firearms or countertops."

"Prosecutors in Travis and Williamson counties will review hundreds of criminal cases after learning of scientific concerns with the way examiners analyze evidence that includes genetic material from multiple people. In a statement Wednesday, Travis County District Attorney Rosemary Lehmberg said her office also discovered an issue with the database it uses to calculate DNA statistics, which are presented in court as probabilities that a given sample included the DNA of a certain person. Lehmberg says her office is unsure how many Travis County cases are affected but says it is working to identify them and notify the parties involved. “The potential impact of changes to the mixture protocols and the database is still unknown, but they may have a material impact on some criminal cases,” Lehmberg said. “This is expected to be a large undertaking, requiring the addition of attorneys and paralegals to our Conviction Integrity Unit. In the interim, this office will work to facilitate any requests for DNA reviews based on the changes.” The FBI first notified crime labs across the country this spring that it had discovered state labs were using outdated protocols to interpret results from DNA data. The problem led to prosecutors overstating the reliability of some DNA evidence in court, which is often presented as accurate to within a fraction of a fraction of a percent. The errors were said to have affected thousands of cases going back to 1999, but officials initially downplayed the impact, saying they were unlikely to result in dramatic changes.........The Department of Public Safety sent a letter Sept. 10 notifying state officials of the changes. But how widespread the problem is and how many cases will be affected across the state remains in question. The Department of Public Safety controls only eight of the DNA crime labs in Texas; counties and police departments oversee others. The advent of DNA testing revolutionized criminal investigations for its reliability in tying suspects to objects collected at the scenes of crimes. But the forensic science continues to evolve and interpretations of the results constantly change. In the latest interpretation guidelines, a given sample will have lower probabilities, translating to more conservative statistics, the DPS letter said. “Just to be on the safe side, they are not going to count all the data they can count,” said Rob Kepple, the executive director of the Texas District and County Attorney’s Association. The old testing could have determined that there was a probability that someone’s DNA was included in an evidence sample, but the new testing could show that scientists can’t determine whether someone’s DNA was included, Kepple said. “That’s important for a defendant to know.” Such disclosures are important as labs test smaller and smaller traces of DNA found on objects, such as firearms or countertops."

 http://www.mystatesman.com/news/news/crime-law/concerns-over-dna-analysis-spur-review-of-hundreds/nn7SZ/