Challenging Breathalyzer Results in Illinois DUI Cases
Breathalyzer tests are often central to DUI arrests—but they are not infallible. If you’ve been charged with DUI in Illinois, it’s critical to understand that breath test results can be questioned, and in some cases, excluded from evidence.
At AKL Legal, LLC, we represent clients in Grayslake, Lake County, and McHenry County, using proven DUI defense strategies to challenge unreliable or improperly obtained evidence.
Illinois DUI Laws and Implied Consent
Illinois operates under implied consent laws, meaning drivers agree to chemical testing (breath, blood, or urine) when operating a vehicle. Refusing a breath test can result in an automatic driver’s license suspension.
However, agreeing to a breath test does not mean the results are beyond challenge. An experienced Illinois DUI defense attorney can often identify flaws that weaken the prosecution’s case.
How Breathalyzer Results Can Be Challenged
There are multiple ways to dispute the accuracy and reliability of breathalyzer evidence in court:
Faulty or Improperly Maintained Equipment
Breath testing devices must be regularly calibrated and maintained. If records show improper maintenance or malfunction, results may be unreliable and subject to suppression.
Operator Error and Testing Violations
Officers must follow strict procedures when administering a breath test, including:
Observing the driver for a required period before testing
Administering the test correctly
Holding proper certification
Failure to follow protocol can invalidate results.
Medical Conditions and External Factors
Certain health issues and environmental factors can produce inaccurate readings, including:
Acid reflux (GERD), diabetes, or respiratory conditions
Use of medications like inhalers or cough syrup
Low-carb or keto diets producing acetone
Exposure to chemicals (paint, gasoline, cleaning agents)
These variables can falsely elevate a reported blood alcohol concentration (BAC).
Inherent Scientific Limitations
Breath tests estimate BAC rather than directly measuring it. This indirect calculation can lead to inconsistencies, especially when compared to actual blood testing.
Was There Probable Cause for the DUI Stop?
Even before a breath test is administered, law enforcement must have probable cause to initiate a traffic stop—unless it occurs at a lawful DUI checkpoint.
If the stop itself was unlawful, any evidence obtained afterward—including breathalyzer results—may be excluded from court.
Why Early Legal Representation Matters
DUI cases move quickly, and early intervention can make a significant difference. A skilled attorney can:
Review police reports and testing procedures
Challenge improper stops or arrests
File motions to suppress unreliable evidence
Negotiate reduced charges or dismissal when possible
Defend Your DUI Case with AKL Legal, LLC
A DUI charge does not automatically mean a conviction. With the right defense strategy, you may be able to challenge the evidence against you and protect your future.
At AKL Legal, LLC, we provide aggressive DUI defense throughout Lake County, McHenry County, and suburban Cook County Illinois.
Call 847-262-9888 today for a free consultation and start building your defense.
