DUI Test Defense Attorneys in Snohomish County

How DUI Testing Works

When someone is arrested for DUI in Snohomish County, law enforcement often relies on specific tests to build their case. These tests—whether on the roadside or at the station—are presented by prosecutors as “scientific proof” of intoxication. But just because a test result says something doesn’t mean it’s accurate, reliable, or even legally admissible.

At DUIHeroes, we’ve spent over two decades challenging DUI testing in Washington courts. Our exclusive focus on DUI defense means we know how these tests are supposed to work, where they often go wrong, and how to expose flaws that can make the difference between a conviction and a dismissal.

To learn more, reach out to a Snohomish County DUI lawyer today: (425) 296-9358.

The Three Main Types of DUI Tests

1. Field Sobriety Tests

Usually the first step in DUI testing, these roadside tests include the walk-and-turn, one-leg stand, and horizontal gaze nystagmus. Officers use them to measure impairment, but the reality is that they are subjective and vulnerable to officer error, environmental conditions, and even factors like nervousness.

Learn more about Field Sobriety Tests.

2. Breath Tests

In Washington, drivers are often asked to blow into a breathalyzer device either at the roadside (preliminary breath test, or PBT) or at the station. Results from the station machine may be used in court as proof of an illegal alcohol concentration, but these devices require strict maintenance, calibration, and proper administration—any failure can make the results unreliable.

3. Blood Tests

If an officer suspects drug use or if a driver refuses a breath test, police may request a warrant for a blood draw. Blood testing is sometimes presented as the “gold standard” in DUI cases, but it’s far from perfect. Lab errors, contamination, and chain-of-custody issues can completely change the outcome of a case.

Learn more about Breath & Blood Tests.

Why DUI Testing Isn’t Always Reliable

Prosecutors in Snohomish County courts may try to treat DUI test results as irrefutable, but we know better. Our founding attorney, Jonathan Dichter, is not only a Faculty Member and State Delegate for the National College for DUI Defense, but he has also completed—and is a qualified instructor of—the NHTSA and IACP DWI Detection and Standardized Field Sobriety Testing Student Course. This is the same course law enforcement officers must complete to administer Standardized Field Sobriety Tests. 

This training enables our team to identify common problems like:

• Improper Training: Officers may not be trained or qualified to conduct field tests correctly.
• Machine Errors: Breath testing devices require routine calibration and strict protocols.
• Medical Conditions: Acid reflux, diabetes, fatigue, or injuries can all impact DUI testing outcomes.
• Environmental Factors: Poor lighting, uneven ground, or weather can affect field sobriety results.
• Laboratory Mistakes: Contamination or mislabeling can taint blood samples.

Each of these issues can be grounds to challenge the prosecution’s case.

How DUIHeroes Challenges DUI Tests

We don’t just take DUI test results at face value—we tear them apart. 

Our defense strategies may include:

• Reviewing maintenance and calibration logs for breath testing machines.
• Examining officer training records and test administration procedures.
• Consulting toxicologists and other experts to challenge blood test reliability.
• Cross-examining officers to expose bias, errors, or shortcuts.
• Highlighting how test results don’t always match real-world behavior or impairment.

With an average of 95% of first-offense DUI charges reduced or dismissed since 2009*, we know how to use weaknesses in DUI testing to our clients’ advantage.

The Bottom Line on DUI Testing in Snohomish County

DUI tests are not perfect. They’re tools used by law enforcement, and like any tool, they can be misused or malfunction. A single mistake in administration, equipment, or analysis can mean the difference between a guilty verdict and an acquittal—or even a dismissal of all charges.

If you have been charged with DUI after a breath, blood, or field sobriety test in Snohomish County, don’t assume the test is unchallengeable. The sooner you involve a defense team that knows DUI testing inside and out, the better your chances of protecting your future.

“Failed” DUI Test? Call for a Free Consultation!

At DUIHeroes, we focus exclusively on DUI defense. We know how DUI tests work—and how they fail. Call (425) 296-9358 for a free, confidential consultation with our Snohomish County DUI attorneys. We’re available 24/7 to answer your questions, review your case, and start building a defense that challenges the evidence against you.

Contact our team now to discuss your case, your rights, and your options.