Can Your DUI Be Dismissed? The Defenses Your Attorney Should Be Exploring

You blew over the limit. Or you think you did. Or you refused the test entirely. And now your attorney wants to talk about plea deals.

But here's what most DUI defendants don't know: DUI cases get dismissed all the time. Not because of legal technicalities that only TV lawyers know — but because of real, specific errors that police officers make during traffic stops, field sobriety tests, and chemical testing.

Your attorney should be investigating every single one of these. If they're not, you're leaving defenses on the table.

Defense 1: The Traffic Stop Was Illegal

The Fourth Amendment requires police to have reasonable suspicion to stop your vehicle. That means the officer needed a specific, articulable reason to pull you over.

Valid reasons for a stop:

• Traffic violations (speeding, running a red light, failure to signal)
• Equipment violations (broken taillight, expired registration)
• Driving behavior consistent with impairment (weaving across lanes, extreme speed variation)

Questionable reasons that get challenged:

• "Weaving within your lane" — courts are split on this, and many find it insufficient
• "Driving slowly" — going 5 mph under the speed limit is not reasonable suspicion
• Anonymous tips without corroboration
• Stopping you for a minor equipment violation as a pretext to investigate DUI

What your attorney should be doing: Reviewing the dashcam footage and the officer's report for the stated reason for the stop. If the reason was insufficient, everything that followed — field sobriety tests, breathalyzer, arrest — can be suppressed.

Questions to ask: "Was the traffic stop legal? What was the officer's stated reason? Does the dashcam support that reason?"

Defense 2: Field Sobriety Tests Were Administered Incorrectly

The Standardized Field Sobriety Tests (SFSTs) — Horizontal Gaze Nystagmus (HGN), Walk-and-Turn, and One-Leg Stand — have strict protocols from the National Highway Traffic Safety Administration (NHTSA).

Common errors officers make:

• Administering tests on uneven or sloped surfaces
• Failing to demonstrate the tests properly
• Not asking about medical conditions that affect balance (inner ear problems, leg injuries, neurological conditions)
• Administering tests in poor lighting or adverse weather
• Using non-standardized tests (finger-to-nose, alphabet recitation) that have no scientific validation
• Misscoring the tests

What your attorney should be doing: Obtaining the officer's SFST certification records, reviewing body cam footage of the test administration, and comparing against NHTSA protocols step by step.

Questions to ask: "Have you reviewed the field sobriety test administration against NHTSA standards? Were there any deviations?"

Defense 3: Breathalyzer Results Are Unreliable

Breathalyzer machines are not infallible. They require regular calibration, proper maintenance, and certified operators.

Common breathalyzer issues:

• Calibration: The machine wasn't calibrated within the required schedule
• Operator certification: The person administering the test wasn't properly trained or certified
• Observation period: Most states require a 15-20 minute observation period before testing (to ensure you didn't burp, vomit, or put anything in your mouth). If this was skipped or shortened, results are challengeable
• Radio frequency interference: Certain electronic devices can affect breathalyzer readings
• Mouth alcohol: Recent use of mouthwash, breath spray, or even acid reflux can inflate readings
• Temperature: Body temperature affects breath alcohol readings — a fever can produce falsely high results
• Margin of error: Breathalyzers have an inherent margin of error (typically ±0.005-0.02). If you blew a .08 or .09, the margin of error alone could put you under the limit

What your attorney should be doing: Subpoenaing the breathalyzer's maintenance and calibration records, the operator's certification, and the observation period log. If any of these are deficient, the BAC result can be challenged.

Questions to ask: "Have you requested the breathalyzer calibration records? When was the machine last calibrated? Is the operator certified?"

Defense 4: Blood Test Errors

If your BAC was measured via blood draw, different challenges apply:

• Chain of custody: Was the blood sample properly handled from draw to lab?
• Fermentation: Improperly stored blood samples can ferment, producing alcohol that wasn't there at the time of the draw
• Contamination: Was the draw site swabbed with a non-alcohol antiseptic? (Using alcohol swabs can contaminate the sample)
• Timing: Blood alcohol levels rise after drinking. If you were tested well after driving, your BAC at the time of testing may have been higher than your BAC while driving (this is called "rising blood alcohol defense")
• Lab accreditation: Is the lab accredited? Has the analyst had results questioned before?

What your attorney should be doing: Requesting the complete blood testing documentation, chain of custody forms, and lab records.

Questions to ask: "Have you reviewed the blood test chain of custody? Was the blood properly stored? What was the time between the stop and the blood draw?"

Defense 5: No Probable Cause for Arrest

Even if the stop was legal, the officer needs probable cause to arrest you for DUI. Probable cause requires more than just the smell of alcohol or a single failed field sobriety test.

Challenge points:

• Did the officer have sufficient evidence of impairment beyond alcohol odor?
• Were there alternative explanations for observed behavior (fatigue, medication, medical conditions)?
• Did the officer's observations match the dashcam/bodycam footage?

Defense 6: Miranda and Right to Counsel Violations

If you were questioned about drinking after being arrested without Miranda warnings, your statements may be suppressed. Additionally, in some states you have the right to consult with an attorney before deciding whether to take a chemical test.

Defense 7: Rising Blood Alcohol

Alcohol takes 30-90 minutes to fully absorb. If you had your last drink shortly before driving, your BAC may have been below .08 while you were actually driving — and only rose above .08 by the time you were tested.

This is a legitimate defense that requires expert testimony, but it's powerful when the facts support it.

What Your Attorney Should Be Doing Right Now

If you've been charged with DUI and your attorney hasn't discussed at least some of these defenses with you, ask why.

A competent DUI attorney should:

1. ✅ Review dashcam and bodycam footage
2. ✅ Analyze the stated reason for the traffic stop
3. ✅ Evaluate SFST administration against NHTSA standards
4. ✅ Subpoena breathalyzer calibration and maintenance records
5. ✅ Review blood test chain of custody (if applicable)
6. ✅ Check officer certification and training records
7. ✅ Investigate the observation period compliance
8. ✅ Consider rising blood alcohol defense
9. ✅ File suppression motions for any violations found

If your attorney's only strategy is "let's see what they offer" — they're not doing their job.

---

This is legal information, not legal advice. We are not attorneys and do not provide legal representation. DUI laws and defenses vary significantly by state — always consult a licensed DUI attorney in your jurisdiction.