Are BAC Blood Tests Accurate?

In many investigations for DUI cases, law enforcement officers will take a blood sample from an arrestee in order to measure their blood alcohol content (BAC). While the results of the blood test are often offered by the Denver prosecution to prove your level of intoxication, there are many reasons why these results may not be completely accurate. In such situations, a defense attorney can challenge the accuracy of the blood test in the following ways.

Improper collection of the blood sample.

The quality of the blood that is tested must remain the same from collection of the sample to testing of the sample. However, the very first opportunity for the sample to be contaminated or compromised is in the initial collection of the sample. If a lab technician is not properly trained in collection of blood sample or is inexperienced, it is very easy for the sample to be contaminated to the point where the accuracy of the test is affected.

Improper storage or handling of the blood sample.

Blood samples are rarely tested immediately and therefore must be stored for a certain period or time prior to testing. Following proper procedures for the storage of blood samples is highly important for preserving the integrity of the sample. However, there are many opportunities for mistakes to be made in the storage of blood samples prior to testing, especially since numerous parties may be handling the sample. For example, the following may cause inaccurate results:

  • Failing to add anticoagulant preservatives
  • Inadvertently adding chemicals with ethyl alcohol to a sample (which can raise the alcohol levels)
  • Not storing a sample in a place with the correct temperature or sterile environment
  • Mislabeling a sample with an incorrect name or making another error that confuses samples
  • Allowing untrained or unauthorized technicians or individuals to handle the blood sample

Improper testing of the blood sample.

Even if a blood sample is properly collected and stored, the actual testing process presents additional opportunities for errors to occur. For example, if a forensic lab waits too long to process and test the sample, any alcohol in the blood may ferment and increase the BAC results. Additionally, testing equipment that is not properly calibrated or maintained can result in widespread inaccuracies.

Reporting errors may also occur, even if the integrity of a blood sample is maintained and the tests are performed correctly. For example, if a lab technician waits too long to prepare a report regarding the results of the tests, they may make errors in the report due to mix-ups or failed memories. Additionally, if a lab does not correctly determine and report the possible error margin in their testing techniques, the result can be an invalid scientific and arbitrary result.

Contact a DUI defense attorney to represent you in your Denver DUI case

A skilled DUI defense lawyer will know how to investigate the techniques and policies of a forensic lab and examine the chain of custody of a blood sample to identify any possibility for contamination or inaccurate results. If you have been arrested for DUI, call the Tiftickjian Law Firm in Denver at (303) DUI-5280 for assistance with your case today.

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