The implements used by police departments throughout Texas to conduct a blood draw from a suspected drunk driver are uncomplicated: a needle to draw the blood from an artery and a glass tube in which to store the blood sample until its blood alcohol content (BAC) can be measured. It’s difficult to imagine how either the needle or the tube could be defective, but the police department at Dallas-Fort Worth Airport (DFW) has been involved in a controversy about an apparent defect in 2,760 tubes that were lacking an important protective coating.
The product recall
In 2018, the manufacturer of the tubes issued a recall of 247,000 tubes because they lacked a preservative power that stabilizes the blood sample until it can be tested. The power helps ensure the accuracy of the measurement of the BAC. In July 2021, investigators for a local TV channel found documentary records that showed that in 2,760 cases, a tube lacking the white power was used take and store a blood sample. Of those arrests, 42 were arrests made by DFW Airport Police.
DFW response to recall notice
The investigation also uncovered a July 2019 e-mail from an airport police sergeant to the Tarrant County District Attorney’s office stating that he was “worried about” recent blood draws that appeared to have used one of the defective tubes. The airport police, however, made no effort to notify suspects that their blood had been drawn using one of the defective tubes.
According to forensic experts, once the tubes are filled with blood, the presence or absence of the preservative powder cannot be determined. Scientific studies have apparently demonstrated that the BAC tends to be reduced if the sampling tube did not contain the preservative powder.
What could be the implications?
The rules of evidence and of criminal procedure in Texas preclude the use of improper or defective equipment to measure BAC. Any defense attorney who believes that his client’s blood was drawn using a defective tube has an important reason to object to the introduction of the suspect’s BAC at trial.