A series of errors by a private laboratory testing company has called hundreds of pending DWI cases into question. Blood samples sent to the lab were reportedly mislabeled, or were subject to other paperwork errors, resulting in uncertain test results. Prosecutors are trying to determine whether retesting is possible, while DWI defendants and their advocates remain skeptical that the state has revealed all of the damage done by the lab’s errors. Laws defining the offense of DWI generally do not require evidence of blood alcohol content (BAC) obtained through blood or breath testing, but chemical evidence is generally considered the simplest way for prosecutors to prove intoxication.
The district attorney’s office in San Antonio, Texas contracted with the laboratory, which is located in the Dallas/Fort Worth area, to test samples taken by police in DWI cases. The lab reportedly sent a letter to the DA’s office in May 2014 informing it that an analyst had made multiple errors in paperwork affecting hundreds of samples. The DA’s office has reportedly not made the full extent of the errors public, but one error by the analyst, who has been terminated by the lab, involved incorrect labeling of 350 samples.
The lab has reportedly sent test results to the DA’s office with notices that they cannot definitively link the results to a specific sample, although the DA’s office has denied that results have actually been mixed up between cases. The office has also denied that any samples were contaminated by the lab, although news media have reported that some documents make reference to contaminated equipment. The situation has left both prosecutors and criminal defense attorneys uncertain how to proceed with pending DWI cases. Continue reading