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The Serious Problems with Texas’ Breath Test Program

In my last trial, Tarrant County Criminal Court no.2, cause no. 1528525, the State’s expert readily conceded facts about Texas’ breath test program that are unacceptable.  

(fig. 1) The Intoxilyzer 9000 is the current breathalyzer used in Texas
(fig. 1) The Intoxilyzer 9000

First, The breath test program for the entire state of Texas is run by a law enforcement agency, The Texas Department of Public Safety. The Scientific Director for Texas DPS comes up with the regulations and oversees the program.  For scientific integrity, a law enforcement agency should never be in charge of forensic, scientific evidence. There are no checks and balances in this system. Power is very dangerous when it all rests in one body. Accordingly, there is a direct conflict of interest allowing the police to be in charge of forensic testing. President Barack Obama created a National Forensic Science Commission to come up with national standards for forensic science. After President Trump took office, he destroyed this body.  It is unwise and unsafe to allow law enforcement agencies to come up with their own standards. Science needs to be left to scientists.

Second, Texas is now using the Intoxilyzer 9000. (fig. 1) This breath alcohol estimator, also known as a breathalyzer, is manufactured by CMI in Kentucky. When purchased, it comes from the factory set to factory calibration. However, Texas DPS requires that each machine be re-calibrated “in house.”  If the manufacturer is producing an accurate breathalyzer, this is not necessary. If the manufacturer is producing an inaccurate breathalyzer, it is not acceptable that Texas uses these machines. This begs the question: What about the other problems in the machine that don’t relate to calibration?

Finally, Calibration should always have traceability. For example, if I calibrate my scale at home and decide that all scales should be judged for accuracy based on my self calibration, it is incumbent that I prove my method is based on accuracy that is traceable. The United States has a department for traceability of measurements, known as the National Institute of Standards and Technology (NIST).  In Texas, individual breath test technical supervisors are allowed to create their own reference solutions and they verify it by testing it on their own labs’ equipment (other breath test estimators or in house gas chromatography machines).  This is unacceptable, particularly when there is no independent, outside scientific group responsible for the estimators’ calibration. 

These are just the basic premise problems with Texas’ programs. The Texas Breath Testing program lacks accountability. Therefore, until there is separation between law enforcement and forensic science, accuracy is not to be expected. It is a fallacy for people to overlook foundational problems of breath testing and render life threatening decisions, such as jail or prison, among other possible consequences.

-Mimi Coffey

The Coffey Firm handles DWI and Criminal Defense cases in Dallas and Tarrant Counties and surrounding counties, including Collin, Denton, Johnson, and Parker Counties. If you need a DWI lawyer, please do not hesitate to contact us.