New Analysis Shows Unreliability of Breath Testing Devices

By FindLaw Staff on November 19, 2019 | Last updated on November 20, 2019

If you do not understand exactly how a scientific device works, it can be much easier to just accept whatever result that device provides.

This is often the situation drivers face with the machines law enforcement agencies use to measure blood alcohol concentration (BAC). However, results from Breathalyzers are often much less reliable than you may have been led to believe.

Breathalyzers and similar devices require careful, precise calibration and operation. If the devices are not set up and operated properly, they can produce skewed results.

Many law enforcement agencies consider any result from a Breathalyzer to be accurate and grounds for criminal charges, but this assumption is changing quickly.

Recent Findings

Recent reports show that thousands of drivers have been convicted of driving under the influence because of highly-suspect breathalyzer data.

Different states use different devices to measure BAC, but each type of BAC-measuring machine requires a trained operator to produce an accurate result. Recently, journalists and some legal entities have discovered that law enforcement agencies around the country have failed to properly calibrate the BAC-measuring machines they use, have operated those machines without proper training, and have hidden and destroyed documentation that could prove the agencies' active negligence.

Breathalyzer Basics and Accuracy

There are several machines that are designed to measure an individual's BAC, and many of them use different methods to generate results. For example, some machines use:

  • Fuel cells that generate an electric current
  • Infrared light
  • Chemical reactions

Additionally, the chemical data obtained by the BAC-measuring machines is fed through a computer system. Researchers have discovered, on multiple occasions, that the programs in these machines have skewed results and/or have not functioned properly due to programming errors.

If you have been accused or convicted of a DUI, it is possible that the devices used to measure your BAC were not used properly and that the findings used to convict you were inaccurate. In fact, some courts have ruled that breathalyzer results will no longer be admissible until law enforcement agencies meet certain scientific standards.

Because of these new findings, some courts are allowing convicted drivers to reopen their DUI cases. For drivers living with DUIs on their records, the possibility of clearing their driving records is potentially life-changing. If you are considering reopening your DUI case, an experienced legal professional could make all the difference.


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