Fighting a Washington DUI: Legal Steps You Should Never Take Alone. .
A DUI Arrest Doesn’t Mean an Automatic Conviction
If you’ve been arrested for DUI in Washington, you might feel like the case is already lost. The breathalyzer, the field sobriety tests, and the officer’s report all seem damning—how do you fight back?

The truth is DUI cases are often more defensible than people realize. The right legal strategy can mean the difference between a conviction and a reduced charge—or even a dismissal.
Here’s everything you need to know about how to fight DUI charges in Washington and why working with an experienced attorney is critical to any type of success.
Understanding DUI Charges in Washington
What Prosecutors Need to Prove in a DUI Case
A DUI conviction doesn’t happen automatically. The prosecution must prove beyond a reasonable doubt that:
- You were driving or in physical control of a vehicle, and
- You were:
- Over the legal limit (0.08% BAC for adults, 0.02% for minors, 0.04% for commercial drivers) OR
- Under the influence of alcohol, drugs, or both, to the extent that your driving was impaired – in other words, if, in the opinion of the arresting officer, you were exhibiting signs of impairment that affected your driving.
Each reason for the arrest presents opportunities for challenge and defense.
How to Fight a DUI Charge in Washington
Step 1: Challenge the Traffic Stop
The officer must have had a legal reason to pull you over. If there was no valid reason, any evidence gathered afterward—including breath tests—may be thrown out.
Possible defenses
- No traffic violations or erratic driving
- An anonymous tip led to the stop (without independent officer verification)
- Racial profiling or other unconstitutional stop
An experienced DUI criminal defense attorney will examine the dashcam, bodycam, and police report to look for Fourth Amendment violations that could get your case dismissed.
Step 2: Attack the Field Sobriety Tests (FSTs)
Most people don’t realize that field sobriety tests are not reliable indicators of intoxication.
Problems with Field Sobriety Tests
- Subjective: The officer decides whether you “failed.”
- Unfair conditions: Poor lighting, bad weather, uneven pavement
- Medical issues: Vertigo, knee or back problems, even anxiety can cause failure
Defense strategies
- Cross-examine the officer on improper instructions or test conditions
- Challenge the validity of the Horizontal Gaze Nystagmus (eye test)
- Provide medical evidence that affected your performance
Step 3: Question the Breathalyzer Results
Washington uses the Draeger Alcotest 9510, a machine that isn’t perfect.
Common breath test problems
- Improper calibration (must be checked regularly)
- Mouth alcohol contamination (mouthwash, acid reflux, dental work)
- Rising BAC (your BAC could be rising at the time of the test)
- Officer error (test must be administered correctly)
Defense strategy
- Request maintenance records for the breathalyzer machine
- Challenge the observation period (the officer must watch you for 15 minutes before the test)
- Hire an expert to refute unreliable results
Step 4: Expose Blood Test Weaknesses
Blood tests seem scientific, but they can be flawed.
Common issues with DUI blood tests
- Improper storage: Blood samples must be kept at a specific temperature
- Fermentation: Can cause false high BAC readings
- Contamination: Dirty needles and alcohol swabs can taint results
Defense strategy
- Request full lab records to check for errors
- Challenge chain of custody (who handled the blood and where it was stored)
- Hire a forensic toxicologist to examine accuracy
Step 5: Fight the Officer’s Report
Police officers are not perfect. Mistakes, biases, and exaggerations happen.
Defense strategy
- Cross-examine the officer on inconsistencies
- Pull bodycam footage to challenge their claims
- Show evidence of bias (e.g., the officer was aggressive or had a prior issue with you)
Step 6: Use Legal Motions to Weaken the Case
Your attorney can file legal motions to dismiss or suppress evidence before trial.
Possible pre-trial motions
- Motion to suppress evidence from an unlawful stop
- Motion to dismiss due to lack of probable cause
- Motion to exclude breath test results due to improper calibration
If key evidence is thrown out, the prosecution’s case may collapse.
Can You Avoid a Conviction Without Going to Trial?
Negotiating for Lesser Charges
Sometimes, the best strategy is to negotiate. Your attorney may work out a plea deal for:
- Reckless driving (no DUI on your record)
- Negligent driving (less severe penalties)
- Deferred prosecution (no conviction if you complete treatment)
Every case is different, and an experienced lawyer knows how to get the best deal possible.
Why You Need a DUI Attorney – Now
Fighting a DUI charge is not a DIY project. Here’s why:
- Prosecutors want convictions—they will not go easy on you
- You may not know your strongest defenses
- A lawyer can get charges reduced or dropped
Don’t risk your future. Get a professional on your side.
Contact Knauss Law today for a free consultation.
FAQs About Fighting a DUI in Washington
Yes. Many DUI cases are dismissed or reduced when properly challenged.
No. A DUI stays on your record for life.
Even if you blew over 0.08, the test can be challenged and excluded from evidence.
It depends on your case, but the cost of not fighting a DUI is much higher (fines, jail, job loss).
The Bottom Line: DUI Charges Are Beatable
If you’ve been arrested for DUI in Washington, don’t panic. You have options.
Step 1: Get a DUI attorney immediately.
Step 2: Challenge every aspect of the case.
Step 3: Don’t settle for a conviction without a fight.