How a DUI Lawyer Can Challenge Breathalyzer Results
- Meason & Morris Law
- Sep 8, 2025
- 5 min read
Being charged with driving under the influence (DUI) is a serious matter that can affect your future, finances, and freedom. For many people, one of the most stressful parts of a DUI arrest is the breathalyzer test. Police often present these test results as undeniable proof of intoxication, but the truth is that breathalyzers are not infallible.
With the right legal strategy, a skilled DUI lawyer can challenge the accuracy and reliability of breathalyzer results. Understanding how this works could make the difference between a conviction and a dismissed or reduced charge.
In this blog, we’ll explain why breathalyzer results may not always be reliable, how a DUI lawyer can challenge them, and why legal representation is essential if you’ve been charged with DUI in Oklahoma.
The Role of Breathalyzers in DUI Cases
A breathalyzer is a device used by law enforcement to estimate a person’s blood alcohol concentration (BAC) through a breath sample. In Oklahoma, a BAC of 0.08% or higher is generally considered legally intoxicated for adults.
While police and prosecutors rely heavily on breathalyzer results in DUI cases, these devices have limitations. A DUI lawyer knows how to analyze whether the test was administered properly and whether the results can be trusted in court.
Why Breathalyzer Results May Be Inaccurate
There are many factors that can cause breathalyzer results to be misleading. Some of the most common include:
1. Improper Calibration
Breathalyzers must be calibrated regularly to ensure accuracy. If law enforcement fails to properly maintain the device, results may be skewed.
2. Human Error
The officer administering the test must follow strict procedures. Errors such as failing to observe the subject before the test or not instructing them properly can make results unreliable.
3. Medical Conditions
Certain medical conditions, such as diabetes or acid reflux, can affect breathalyzer readings. For example, high levels of acetone in a diabetic’s breath may register as alcohol.
4. Mouth Alcohol
Residual alcohol in the mouth from recent drinking, mouthwash, or even certain foods can artificially inflate BAC readings.
5. Environmental Factors
Substances in the environment—such as paint fumes, chemicals, or even certain medications—can interfere with the device’s sensors.
A DUI lawyer investigates all of these possibilities to see if breathalyzer evidence can be challenged.
Legal Grounds for Challenging Breathalyzer Results
When defending a client, a DUI lawyer will explore every possible legal angle to question the validity of breathalyzer evidence. Some common defenses include:
1. Questioning the Device’s Accuracy
If the breathalyzer was not calibrated, maintained, or tested properly, its results may not be admissible in court.
2. Challenging Officer Procedures
Police must follow specific rules when administering a breath test. Failure to observe a waiting period, improper handling, or skipping steps in the protocol can make results invalid.
3. Medical and Biological Factors
Your lawyer may present medical evidence showing that a health condition influenced the test results.
4. Chain of Custody Issues
Any evidence collected in a DUI case must be handled properly. If there are gaps in the chain of custody for breathalyzer data, the evidence may be thrown out.
5. Constitutional Rights Violations
If you were stopped or arrested without proper legal justification, your lawyer can argue that all evidence—including breathalyzer results—should be excluded.
Real-World Example: Breathalyzer Defense in Action
Consider this example: A driver is pulled over late at night and blows a 0.09% on a breathalyzer. However, their DUI lawyer discovers that the device had not been properly calibrated for months. The lawyer files a motion to suppress the evidence, and the judge agrees, ruling the test results inadmissible. With the main evidence gone, the case is dismissed.
This scenario demonstrates how powerful a breathalyzer defense can be when handled by an experienced attorney.
Other Evidence a DUI Lawyer May Review
Breathalyzer results are only one piece of a DUI case. A strong defense will also consider:
Field Sobriety Tests: These can be highly subjective and influenced by fatigue, medical conditions, or uneven road surfaces.
Dash Cam or Body Cam Footage: Video evidence may reveal errors in how the stop or arrest was conducted.
Witness Testimony: Passengers or bystanders may provide accounts that contradict the officer’s claims.
Blood Tests: These are sometimes more reliable than breath tests, but they must be handled correctly.
By examining all available evidence, a DUI lawyer can build a comprehensive defense strategy.
Consequences of a DUI Conviction
In Oklahoma, DUI penalties can be severe, even for first-time offenders. Consequences may include:
Fines and Court Costs
Driver’s License Suspension
Mandatory Alcohol Education Programs
Probation
Jail Time (for repeat or aggravated offenses)
Increased Insurance Rates
Because of these harsh penalties, it is critical to have an experienced DUI lawyer review every aspect of your case before accepting the results of a breathalyzer as final.
Why You Should Never Assume Breathalyzer Results Are Final
Many people charged with DUI believe they have no choice but to plead guilty if they failed a breathalyzer test. This is not true. Breathalyzer evidence is not always reliable, and there are many ways to challenge it.
The outcome of your case could be drastically different with the help of a knowledgeable DUI lawyer who knows how to fight these results.
How a DUI Lawyer Helps You
Here’s what you can expect from working with a DUI lawyer at Meason & Morris Law:
Thorough Case Review: Examining every detail of your arrest, including the breathalyzer process.
Evidence Analysis: Checking calibration records, officer training, and procedural compliance.
Defense Strategy: Identifying the best arguments for suppressing or challenging evidence.
Court Representation: Advocating for your rights in front of judges and prosecutors.
Negotiation: Working to reduce charges or penalties if a dismissal is not possible.
With skilled legal guidance, you stand a much better chance of protecting your record, license, and freedom.
Frequently Asked Questions About DUI Breathalyzer Tests
1. Can I refuse a breathalyzer test in Oklahoma?
Yes, but refusal can lead to automatic license suspension under implied consent laws.
2. Are portable breath tests the same as official breathalyzers?
No. Portable roadside tests are less accurate and often not admissible in court.
3. Can breathalyzer results be used as the only evidence in a DUI case?
Typically, prosecutors rely on multiple forms of evidence, but breathalyzer results are often the centerpiece.
4. How long does alcohol stay detectable on a breath test?
It depends on factors like body weight, metabolism, and how much was consumed, but usually a few hours.
Final Thoughts
A DUI charge is frightening, but a failed breathalyzer test does not automatically mean you’ll be convicted. Breathalyzer devices are not perfect, and their results can be successfully challenged in court with the help of an experienced attorney.
At Meason & Morris Law, our skilled DUI lawyers have the experience and knowledge to identify flaws in breathalyzer evidence, protect your rights, and fight for the best possible outcome.
If you or someone you love is facing DUI charges, don’t wait. Contact us today to schedule a confidential consultation and take the first step toward protecting your future.
Meason & Morris Law is a legal firm led by seasoned attorneys Marty Meason and Chris Morris. We provide a professional experience for all our clients, helping them navigate their legal rights. We focus on Criminal Justice Law (felonies and misdemeanors), Divorce and Family Law, Expungement and Felony Law, Probate Law and also have Trial experience. Serving Washington County, Nowata County, Osage County, Rogers County, Payne County, Pawnee County, and Kay County in Oklahoma.
Meason & Morris Law
515 Delaware Ave
Bartlesville, OK 74003
918-336-6300
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