DUI Breath Tests

One of the main pieces of evidence that is used in DUI cases is blood alcohol content (BAC). Although these tests are frequently administered, there is controversy surrounding them. For example, they are only supposed to be administered when an officer has probable cause. In most cases, a driver is asked to take this test when they are showing signs of impaired driving, such as swerving.

Our Chicago DUI lawyer at O’Meara Law has over 20 years of experience in the criminal justice system. With spent as both a prosecutor and a criminal defense attorney, attorney Michael O’Meara can anticipate the prosecution’s strategy to develop a strong defense for you. Call 312-909-0706 now to find out more.

Types of Breathalyzers

When a person is suspected of driving under the influence, they may be subjected to two rounds of testing. The first is referred to as a preliminary breath test, otherwise known as a field sobriety test. If the driver registers a BAC of above .08 percent, they will very likely be arrested. In fact, any BAC of above .05 percent has a high likelihood of resulting in a DUI. After the arrest is made, the second round of breath tests takes place. Once a person is in custody, they may be required to take an evidentiary breathalyzer test. Typically, these tests are far more accurate than handheld machines that are usually used on the side of the road.

While handheld devices are notorious for false readings, there are some that produce accurate results. For example, the Alcosensor III and IV are both handheld breathalyzers that utilize fuel-cell technology for alcohol detection. As a person blows into the device, the platinum contained within the cell oxidizes any alcohol that passes through. Through chemical processes, an electrical current is produced that is translated into BAC by a microprocessor. While reliable, these devices need consistent calibration that is often not maintained.

The machines that are commonly found in police stations use infrared light to detect alcohol. These breathalyzers operate based on the principle of spectroscopy, or the idea that molecules absorb infrared light in different ways. For example, ethanol (alcohol) absorbs this type of light at different wavelengths when compared to water. By analyzing the extent to which infrared light is absorbed, alcohol can be easily identified among the thousands of chemical compounds in a person’s breath.

Obtaining Valid Results

When an accurate breathalyzer, such as one that relies on infrared spectroscopy, registers a BAC of above .08 percent, the results can be used by the prosecution in court. This is powerful evidence, but there are ways to counter it. If you have been arrested and you are being asked to submit to a breathalyzer test, you should request to speak with an attorney. Having legal assistance can ensure that the proper chemical testing procedures are being followed. If the rules of administering a chemical test are not being adhered to, it may be possible suppress the results in court.

Regulations that must be honored by police during a chemical test include, but are not limited to:

  • Chemical testing must be performed soon after being arrested
  • The machine must be frequently checked and adjusted
  • Breath or blood samples must be analyzed based standard procedures
  • The person administering the test must be qualified to operate the machine and analyze the results

Defenses to Test Results

In the court system, prosecutors and judges operate on the assumption that breathalyzers are accurate and reliable. Any experienced DUI lawyer knows, however, that slight malfunctions and operator errors can cause these examinations to produce faulty results. As such, it may be possible to challenge the result and get your breath test results dismissed in court with one of the following defenses:

  • Unqualified Operator – According to state law, only those who have been properly trained are allowed to administer a breathalyzer test. Having an operator that does not follow procedure when gathering test results can lead to your charges being eliminated.
  • Radio Interference – Many devices, such as police radios, phones, and other electronics can cause interference during chemical test. To avoid this, officers are required to perform regular tests to ensure the accuracy of breathalyzer results.
  • Irregular or Poor Calibration – According to many breathalyzer operation manuals, these machines need to be calibrated frequently. When they are not properly maintained, they can produce faulty results that are not usable in court.
  • Medical Conditions – Several conditions, such as acid reflux, can cause your BAC to skyrocket. There is even a rare disorder, known as auto-brewery syndrome, that results in a person’s blood alcohol content being raised without the consumption of alcohol.

How O’Meara Law can Protect Your Freedom

Being accused of driving under the influence can be a terrifying experience, especially when you could face time spent behind bars. Being convicted of a crime can be especially difficult if you are the sole provider for your family. If you are sent to jail, you may not know how your loved ones will survive. There may also be collateral consequences for a conviction, such as not being able to find employment. Going back to school might also be impossible, as most schools thoroughly screen applicants for criminal histories.

Call O’Meara Law at 312-909-0706 now to see how you can keep your record clean and maintain your freedom.