Concern grows over DNA evidence errors in Texas

Photo does not have a caption

HOUSTON – Forensic labs are already backed up with tons of work and now prosecutors say they will have to go back and retest a lot of old cases.

This afternoon the Texas Forensic Science Commission held a tense meeting discussing misinterpretations with DNA analysis.

They said since the late 1999 scientists used a common formula to determine the likelihood that someone on trial would have the same genetic makeup as someone else and the FBI has flagged what it calls minor discrepancies.

"We hear the scientists testify, 'the chances of somebody else having this exact same type of DNA other than identical twins, is one in 10 quintillion.' Well, those are good numbers and they are very powerful on juries, juries get that stuff and will convict based on it. Well, what they're doing now is because of this population study, those numbers were wrong and they under-calculated the population," William Diepraam, Waller County assistant district attorney said.

Nearby counties said they will retest critical cases.

Diepraam said that will be cases that heavily relied on DNA, and for example, did not have a confession, multiple witnesses, or fingerprint evidence to back up the DNA claims.

"So DPS and frankly any agency, the Harris County Sheriff's Office, the Institute of Forensic Science that use DNA and use these numbers, they're going to have to recalculate all of their cases," he said. "So there are potentially thousands of cases out there that could be impacted. What are the chances that there is somebody innocent sitting in jail on this? It's not probable but it's possible."