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Tennessee DUI: Questioning the Validity of the Breath Test

This time of year is especially busy with holiday parties and other festivities taking place in Davidson County. With the increase of these events, the risk of getting pulled over for alleged drunk driving is higher. As part of the process to determine someone is over the legal limit, a law enforcement officer administers a breath test. If the breath test shows that a person's blood-alcohol content level is 0.08 or above, then that person will be arrested and charged with DUI.

Breath test machines called into question

In the last couple of years, the accuracy of breath tests has been questioned by attorneys and judges alike. Last year, several DUI cases were thrown out by Ohio judges who determined that the state's machines were faulty, according to WKYC. The state said that the machines are just fine but over 36,000 people were arrested for drunk driving in one year. The reluctance of judges to accept the breath tests led several cities to suspend the use of these machines.

Ohio isn't the only state to question breath tests. In Pennsylvania this year, a ban was placed on tabletop breath test machines after a judge also questioned their accuracy. According to The Morning Call, several people were able to get their DUI cases thrown out after a judge ruled machine results were not reliable, due to a possible calibration error.

Breath test variables

It is widely believed that a breath test is based on science but this is not the case, according to the State University of New York. A breath test determines the presence of ethyl alcohol, but it may also pick up substances that are similar molecularly, depending on the machine. This means that someone who has not had a drop of alcohol could fail a breath test.

One test conducted, involved a man who performed a couple of projects that used oil-based paint and contact cement. When he was given a breath test 20 minutes after his exposure, his BAC was 0.12, showing that chemicals can have a direct influence on the test. Other variables that can impact a breath test include:

  • Dirt.
  • Moisture.
  • Blood.
  • Cell phones and police radios.
  • Tobacco smoke.
  • Body temperature.

Even a person's health condition may produce a false BAC reading and judges are beginning to pay attention. The Arizona Supreme Court ruled this summer that people can present evidence in their DUI defense that these tests can be influenced by such factors, according to the Arizona Daily Star. The argument was brought before the court after prosecutors tried to prevent such evidence from being presented and a judge ruled against them.

When a person is facing a DUI charge, there are many consequences that they face. Therefore, it is important for them to meet with an experienced attorney to discuss their case and options.