Challenging BAC test results associated with breath tests/Breathalyzers

Breathalyzer results play a critical role in most DWI cases in Missouri. A drunk driver in Missouri will have to undergo a breath test that can be used as evidence in a court of law.
You can, however, challenge these evidential tests in court. The success of challenging breathalyzer results will largely depend on particular facts and the circumstances of your case and the skill of your attorney. But generally, breathalyzer test results can be challenged in the following ways;

(i) Breathalyzer not reliable

Scientific studies have shown that some breathalyzers provide inaccurate results. A lawyer can challenge BAC test results by showing that the device used is not scientifically reliable. The prosecution fails to convince the judge that the breath test was scientifically reliable, it can be excluded.

(ii) Breathalyzer not properly calibrated

Breathalyzers, just like any other electronic measuring equipment, have to be correctly calibrated to give accurate blood alcohol concentration results. Therefore, it is possible the officer did not calibrate the breathalyzer prior to conducting the breath test, which might have contributed to false positive results.

(iii) Suspect had a medical condition

Certain medical conditions and medication can affect the results of a BAC test. An example is an acid reflux and salmeterol, which can result in false positive reading for alcohol.
A Missouri lawyer can challenge the test results based on the medical condition of a driver at the time of testing. This defense can succeed if the defendant has a known medical condition which could affect the test and give false results that show a reading above the legal limit.

(iv) 15-minutes observational period was not conducted

Under Missouri law and regulations, an officer must observe a driver for at least 15 minutes before administering a breath test. During this period, the driver should not smoke, vomit or ingest anything orally.
The reason for observing this period is to ensure the breath sample is not contaminated by any residual compounds in the mouth that might contain alcohol. If the officer did not wait for 15 minutes before conducting the test, then you can successfully challenge the breath test results.

(v) Breathalyzer not properly maintained

Certain factors, including the temperature of the testing device, can affect BAC results. As such, they must be appropriately maintained. According to the Missouri Department of Health(DOH), all breath test machines must be checked for accuracy after every 35 days.

With the help of an expert, your defense team can mount a challenge in court to prove that the measuring equipment was poorly maintained which might have contributed to false positive readings. This can get the prosecutor evidence dismissed and your DWI charges dropped.

(vi) The breath test administrator was unqualified

According to Missouri laws, the officer conducting a breath test should be qualified. Your attorney can successfully challenge the suitability of the officer undertaking the result. If the prosecutor fails to prove that the officer has the required skill and experience to conduct the test, then any implicating results obtained from the test will be inadmissible in court.

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