Tuesday, December 3, 2024
The Latest DUI News and Information From DUI Defense Attorneys Across the Country

DWI Blood Test Errors

Generally speaking, blood is considered the “gold” standard in forensic testing.  Many DWI blood test errors occur without anyone in the prosecutor’s office understanding or caring. Please see attached the same blood tested by the State (.36) and an independent retest (.25). Under Texas law both labs have been certified by the Texas Forensic Science Commission to meet blood test admissibility standards.  Although the blood is far above the legal limit, this is not the issue. The fact both blood scores are so far apart is scientifically unacceptable.  The State always attempts to argue evaporation may account for some small difference. It certainly would not account for such a huge difference. There is a plethora of reasons for such differences. Just to name a few: improper method validation, inaccurate pipettes and diluters, incorrect values for calibrators and controls, improperly labelled samples, SOP lacking in ISO 17205 standards, the list goes on.   It is scary judges are not throwing out blood results when  machines are not properly validated and the results are unreliable.

DWI blood test errors are scary in that even when found, rarely does it make a difference to a prosecutor or judge. In Texas, you have the right to an independent blood test.  If you request one and the officer does not accommodate, this fact that may be used as evidence against the State in trial.  Of course, you can have your blood retested at your own expense. The law requires for the blood result to be admissible in court, the lab must be certified and approved by the Texas Forensic Science Commission. My office and I frequently have our clients’ blood retested. The problem is we cannot obtain a true, independent blood test.  Only labs which fall under the purview of the Texas Forensic Science Commission qualify for blood admissibility in courts.   The Texas Forensic Science Commission has failed to take meaningful steps in several complaints:  using improper testing equipment for THC (one expert pointed out using a GC for THC testing may produce false positives due to the derivatization of the sample).  Texas DPS labs reported blood results to police departments despite defective test tubes which lacked preservative. Until  there is strong accountability in forensics, judges and prosecutors will continue to use the very labs and analysts who are not held responsible for their errors. Absolute power corrupts absolutely.  Science can’t be trusted where there is no accountability for errors.

Texas DWI Blood Tests- Problematic
DWI blood tests are not the gold standard. Many north Texas labs fail to follow proper procedures.
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Mimi Coffey

Mimi Coffey is a trial attorney with 24 years experience. She is the founder of The Coffey Firm, serving Dallas, Tarrant and Collin counties. She is board-certified in DWI by the National College of DUI Defense (NCDD) and is a Regent of the NCDD. Mimi Coffey also listed on several “top” directory listings such as DWI attorneys Tarrant County, DWI Lawyer Fort Worth, DWI attorney Dallas County, DWI attorneys Collin County and DWI attorneys Parker County. I am very involved with the community DFW caring DWI lawyer, Texas Tech School of Law foundation and I enjoy using the skills I have developed to give back to the community. She has also appeared numerous times as a legal commentator for CNN, National Fox News, as well as local Dallas/Fort Worth stations on DWI-related stories. She is also a frequent speaker at both national and statewide seminars. She is a prolific trial attorney with a proven trial record. She has tried over 300 cases, with 80% of them being jury trials in her 18-year career. Her success includes everything from .21 breath tests, blood tests to 3 car accident cases just to name a few. Mimi’s cases have also made good case law for the State of Texas. For example, in Tarvin v. State, it was found that weaving within your own lane was not a traffic violation. In Lajoie v. State, the courts determined that the defendant’s request to have his attorney must be suppressed as opposed to used as evidence of guilt. She is the author of Texas DWI Defense: The Law and Practice. She is also the author of three nationally-published articles and four statewide articles. Mimi has twice attended Indiana University’s Borkenstein Course for state toxicologists both on alcohol and drugs. She has also completed the NHTSA SFST Course, SFST Instructor Course and the 12-Step DRE Mini-Course Program. She is also one of the first attorneys in the United States to attend the Axion Labs Gas Chromatography Training. Her minor in college was Geology lending her a comprehensive and disciplined scientific mind when it comes to scientific and mathematical issues such as blood and breath testing. Mimi has won the President’s Heart of a Champion Award presented by the Texas Criminal Defense Lawyers Association (TCDLA) numerous times. Mimi also led the effort to get the State Bar of Texas’ Board of Legal Specialization to recognize the NCDD’s DWI Certification. Mimi has been active in 4 legislative sessions in fighting against bad DWI laws. Her efforts prevented the breath/blood test refusal as being a separate crime. She has advocated for true deferred adjudication for DWI. Mimi also sued a Dalworthington Gardens police officer for illegally drawing blood. Since her lawsuit, the 2nd Court of Appeals ruled against police officers drawing blood. (The Court of Criminal Appeals overturned this). Mimi also sued the Texas Department of Public Safety for its double jeopardy surcharge program. Since the initiation of her suit, Texas DPS has instituted amnesty programs based on one’s earning potential.

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