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How to Beat a DUI

Based on Fighting 1000’s of Cases

How to Beat a DUI: #1 Guide to DUI Defense (2024)

The Definitive Guide on How to Get Out of a DUI

Written by Tsion Chudnovsky and Robert Weinberg

If you’ve been charged with DUI or DWI, you are innocent until prosecutors prove guilt beyond a reasonable doubt. That is a very high burden of proof for the DA.

You can beat a DUI charge by identifying legal flaws or doubts about any key evidence required to convict under VC 23152. Inaccurate breathalyzer BAC testspolice errorsmedical conditions and dozens of DUI defenses can be used to fight a DUI and get DUI cases dismissed or charges reduced.

This is why the best DUI lawyers get DUI charges dropped everyday.

The best part?

Here our Los Angeles DUI attorneys review how to beat a DUI case using the 20 best DUI defenses. And they’re all distilled from fighting 1000’s of DUI cases.

You can also win a DUI case in 2022-2023 using legal motions, objections and arguments that may have nothing to do with whether you were over the legal BAC limit.

While DUI laws vary by state, legal defenses can be used to fight a DUI charge in all states including California. Let’s get started…


Wondering how to get a DUI dropped? Here is a guide with the 20 best DUI defense strategies for how to fight a DUI to get DUI cases dismissed and DUI charges dropped.

1. Breathalyzer test errors or inaccuracy

DUI breath tests are the most common blood alcohol concentration (BAC) test.

But did you know:

DUI breathalyzers don’t measure BAC directly?

Instead, they measure breath alcohol then multiply that by a “partition ratio” to estimate BAC. Breathalyzers assume a ratio of alcohol in your exhaled breath to alcohol in your blood of 1:2100.

However, actual ratios of tested individuals range from 1:1300 to 1:3000 or more depending on: sex, body weight, breathing patterns, body temperature and hematocrit levels (red blood cell ratio).

Several issues can cause false positive breathalyzer results:

  1. Physical differences between drivers that affect the partition ratio
  2. The device’s margin of error
  3. Improper calibration, maintenance or use by the police officer
  4. Auto-brewery syndrome

Even when a DUI BAC test is executed flawlessly, experts agree that chemical testing has an error rate of between .005 to .02%.

This allows our Orange County DUI attorney to fight even “flawless test results” between .08 and .10% because a .02% margin of error could lower the BAC to below the legal .08 alcohol limit.

2. Ketosis from Atkins-style diets or diabetes

Conditions such as diabetes, hypoglycemia or low carbohydrate diets (i.e. Paleo or Atkins-style diets) can trigger Ketosis.

Ketosis is a normal metabolic process triggered in your body when it doesn’t have enough carbohydrates from food for your cells to burn for energy.

Without sufficient carbohydrates, your body will burn fat cells instead and produce ketones. For people with diabetes, ketosis is typically a sign of not using enough insulin.

You may be wondering:

“What do ketones have to do with DUI?”

When ketones are eliminated from our bodies through breath and urine, they convert into alcohol. This mouth alcohol can cause breath testing instruments to read inaccurately high BAC levels.

3. No probable cause for the DUI stop

Police DUI stops must be supported by reasonable suspicion or probable cause. Traffic stops are temporary detention by Police and considered a “seizure” under the 4th Amendment.

For DWI stops, the most common reasons Police provide are drivers exhibiting NHTSA driving impairment patterns, speeding or running stop lights.

This is important:

If the officer does not have a reasonable suspicion or probable cause for the stop, your Newport Beach DUI lawyer can file a motion to suppress evidence to exclude any evidence obtained by illegal search. This suppression motion or “1538.5 motion” can exclude the DUI BAC tests from admissible evidence, except for DUI sobriety checkpoints.

Suppressing key evidence can significantly increase the chances of getting a DUI dismissed since 23152 VC has requirements police must prove with valid, admissible evidence.

4. Rising blood alcohol

Rising blood alcohol defense infographic.

Rising blood alcohol” defenses apply when your BAC was below legal limits when driving, but rose above the California blood alcohol limit by the time Police tested your BAC level.

Alcohol can take 45 minutes to 3 hours after drinking to become fully absorbed. This delay causes rising BAC levels as you wait around. The peak BAC time after drinking varies widely based on your body, when and what you ate, and other factors.

You might be wondering:

How do I prove my BAC was below the legal limit?

A rising blood alcohol defense requires using a toxicology expert to examine the results of the BAC test and evidence to create a retrograde extrapolation analysis that shows the driver had rising BAC and was below the legal alcohol limit at the time of driving.

  • There was a significant delay between being pulled over and when the BAC test is administered.
  • Your tested BAC level was close to the California BAC limit, perhaps in the .08 to .11 range.
  • You didn’t exhibit other clear signs of intoxication such as traffic violations, swerving or slurred speech.
  • You were near your destination when stopped so you would not have been DWI.

5. Auto-brewery syndrome (gut fermentation)

Auto-brewery syndrome is a rare medical condition where alcohol is produced in a person’s digestive system – without drinking any alcohol. Sometimes very intoxicating amounts of alcohol.

The condition is most often linked to diets high in carbohydrates and refined foods and the overuse of antibiotic drugs. For those affected, yeast or bacteria in the intestinal tract convert sugar and carbohydrates into alcohol – similar to the fermentation process for beer.

You cannot be born with auto-brewery syndrome. But medical conditions, such as Crohn’s disease, diabetes and short bowel syndrome can trigger too much yeast in the gut and set off the condition.

If the condition can be proven via recognized testing, a Santa Monica DUI lawyer can use this diagnosis to get a DUI dismissed.

6. Inaccurate DUI blood test

Blood testing for alcohol must follow strict protocols to ensure accuracy and there are several ways blood tests can provide inaccurate results.

One example is that it is common for blood samples to sit for days before analyzing. Blood is an organic substance that decomposes due to enzymes and bacterial action. Decomposition can create alcohol in the blood.

Blood samples with no alcohol can generate BAC readings of .25 or more, depending on the amount of fermentation. Fermentation can occur if a technician doesn’t properly refrigerate the sample or add the right amount of preservative.

Blood tests by law enforcement are presumed by courts to be accurate and the burden is on defense to prove that they are not. One way to accomplish that is to file a “blood split motion” to retest the blood and learn details about how the blood was stored and the BAC blood test conducted.

The most common factors to taint DUI blood testing results are:

  1. Improper storage of blood sample
  2. Fermentation of the blood sample
  3. Contamination of blood samples

If errors are found, your Long Beach DUI attorney can fight to have the blood test results excluded from evidence. Suppressing evidence can win a DUI case since valid proof of at least a .08 BAC is required for DUI conviction under California 23152(b) VC.

Breathalyzer test and blood alcohol level errors can be a basis for getting a DUI charge dropped or your DUI dismissed.

7. Inaccurate field sobriety test

California’s Standardized Field Sobriety Tests (SFST) are not accurate indicators of impairment.

There are only three SFSTs that have actual data to verify their accuracy:

  • Horizontal Gaze Nystagmus (77% accurate)
  • One Leg Stand (65% accurate)
  • Walk and Turn (68% accurate)

And these results are for properly administered tests under ideal conditions, which often is not the case. Anyone who has taken a field sobriety test can attest they can be hard to pass sober, let alone on the side of a road in the middle of the night.

Reasons for innocent test failures can include:

  • Poor coordination or non-athleticism
  • Nerves and police officer intimidation
  • Bad lighting or uneven surface conditions
  • Vertigo or poor balance
  • Shoes or clothing that interfere with testing

8. DUI with no proof of driving

One of the key elements needed to prove you were driving under the influence is that prosecutors must prove you were driving the vehicle.

Proving DUI with no proof of driving can be a challenge for prosecutors:

  • If Police found you in a parked car
  • If your car was in an accident, but no one saw you actually driving the vehicle DWI

9. Violations of California Title 17

Title 17 of the California Code of Regulations (Title 17), sections 1215-1221 define many specific requirements for DUI blood alcohol tests.

Key Title 17 requirements include:

  1. Technicians must not use an alcohol-based cleaning agent to sterilize the draw site.
  2. Only authorized technicians may perform the blood draw.
  3. The technician must add the correct amount of preservative and anticoagulant in the vial to ensure the sample does not ferment or clot.
  4. The preservative and anticoagulant used must not be expired.
  5. The preservative and anticoagulant must be properly mixed with the blood sample.
  6. The blood sample must be properly refrigerated and stored.

If there are violations of Title 17 requirements, the BAC blood alcohol test results may be excluded or cast into doubt. Skilled Huntington Beach DUI lawyers know how to get a DUI dropped if BAC test results are excluded.

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10. DUI police report errors & misconduct

Police officer misconduct can cause DUI charges to be dismissed or evidence thrown out if Police procedures aren’t properly followed, regardless of whether you were driving under the influence or not.

Some example issues include:

  • Not following California Title 17 requirements
  • DUI Police report errors, inaccuracies or missing information
  • Fabricated, illegally obtained or manipulated evidence
  • Police officer not giving truthful testimony in court

11. Mouth alcohol

Studies of Breathalyzers have shown that most cannot accurately distinguish readings for ethanol (ethyl alcohol) from other similar methyl group chemical compounds that can be in your mouth. DUI breath testers capture a sample breath of “alveolar air” from deep in your lungs.

This is key:

Equipment can also capture “mouth alcohol” that is not due to drinking alcohol. This causes an alcohol breathalyzer test results accuracy issue because the device can show a false positive high BAC level with little or no actual ethanol in your body.

Mouth alcohol can be caused by:

  • Oral medications such as Anbesol, Vicks Formula 44, NyQuil and some cough drops
  • Asthma inhaler ingredient Albuterol
  • Breath spray and oral herbal tinctures
  • Small amounts of alcohol soaked food caught in dental work
  • Burping or regurgitating

12. GERD and medical conditions

Even the best Breathalyzer DUI breath tests are susceptible to false readings from the following medical conditions that can create mouth alcohol caused by acid traveling from the stomach to the mouth:

How to Get Out of a DUI

13. Improper DUI sobriety checkpoint

While some believe sobriety checkpoints are unconstitutional and violate probable cause protections, the California Supreme Court ruled that DUI sobriety checkpoints are legal, administrative inspections similar to airport screenings exempt from 4th Amendment rules requiring probable cause.

Even though Police don’t need probable cause to stop drivers at sobriety checkpoints, they are subject to many strict legal requirements:

  1. The criteria for stopping drivers has to be neutral.
  2. Police should publicly advertise roadblock locations ahead of time.
  3. The time and duration of the sobriety checkpoint should show “good judgement.”
  4. The checkpoint must display sufficient indicia for its official nature to be clear.
  5. Supervising Police officers must make the operational decisions.
  6. Police should detain drivers for a minimal amount of time.
  7. The checkpoint must be in a reasonable location.
  8. Police must take adequate safety precautions.

If Police fail to meet these requirements, a skilled DUI lawyer can challenge any resulting DUI arrest.

14. Innocent reasons for DUI symptoms

Police officers often testify that you exhibited physical signs and symptoms of drinking such as red eyes, slurred speech or an unsteady gait.

But look:

These same physical signs can easily have innocent explanations that do not mean you were driving under the influence such as:


  • Slurred speech → Fatigue or stress about Police
  • Red or watery eyes → Allergy symptoms
  • Alcohol odor on breath → Illness, oral medication
  • Unsteady gait → Physical injury
  • Flushed facial skin → Sunburn or Rosacea

Innocent explanations can help create a reasonable doubt about the physical signs and symptoms.

5. Disconnect between BAC & actual impairment

Sometimes defendants exhibit little to no impairment but tests show a high BAC level. When this disconnect occurs, it is a red flag there’s a potential false positive BAC test result that may be inaccurate.

DUI defense attorneys can use this disconnect to effectively challenge the evidence and introduce a reasonable doubt about a critical element required to prove guilt.

16. Radio frequency interference

Breath test devices utilize electromagnetic and electrochemical technology to detect alcohol contained in a person’s breath.

These sensitive electronic devices are susceptible to radio frequency interference (RFI) and electromagnetic interference (EMI) that can cause them to indicate erroneously high BAC levels.

Devices that may cause RFI reading errors:

  • Police radios
  • FM and AM radios
  • Microwaves
  • Police radar units
  • Cell phones
  • Security cameras

Prosecutors and DUI criminalists are usually quick to point out that a DUI breathalizer may have an RFI detector to refute the presence of radio frequency interference.

The problem is, independent expert tests of the detectors have shown they are inaccurate and there are frequency ranges the RFI detectors simply cannot see. When devices emit interfering waves in those frequency bands, the RFI detector will not detect them.

17. Lack of mental impairment

Police officers typically claim defendants exhibited physical symptoms of being intoxicated such as slurred speech, red or watery eyes or an unsteady gait.

But it is key that:

California DUI laws define both mental and physical impairment. DUI experts have found that impairment from alcohol and drug consumption will always appear first as mental impairment.

So if a Police officer testifies that you exhibited physical impairment, but not mental impairment, DUI defence lawyers can refute the accusation that you were DUI per California 23152(a) VC.

The final three affirmative defenses involve the defendant admitting to DUI, but proving other facts that excuse or justify the criminal act under California law.

Affirmative defenses are rarely used and the burden of proof is on the defendant. However when the facts support it, the following affirmative defenses can provide a powerful defense at trial:

18. Involuntary intoxication

When a defendant is drugged by someone without their knowledge or unknowingly drinks intoxicating alcohol.

For example:

If someone spikes the punchbowl at a party and a defendant gets drunk as a result drinking what they believe to be punch.

However, you can generally only claim involuntary intoxication if you did not voluntarily take any intoxicating drugs or alcohol.

19. Mistake of fact

When a person has a valid reason to honestly believe they are not intoxicated.

An example mistake of fact would be if the defendant had provable reasons they thought the impairment effect of a prescription medicine was gone.

20. Necessity

In California the legal defense of “necessity” excuses DUI when a defendant must drive when it is done only to avoid a greater harm in an emergency.

Criminal jury instructions 3403 outline how the accused can be acquitted of DUI if they:

  • Acted in an emergency to prevent significant bodily harm or evil to themselves or another.
  • There was no adequate legal alternative.
  • The DUI did not create a greater danger than the one avoided.
  • AND, the defendant did not substantially contribute to the emergency.

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That’s 20 of our best defenses!

If you are wondering how to get out of a DUI in California and want to hire a top DUI defense lawyer, we invite you to call for a Free consultation. No matter how smart you are, it is nearly impossible to fight DUI charges without a lawyer.

We serve clients throughout southern California from our offices in Los Angeles & Orange County and defend clients for all types of DUIs including first DUI charge, second DUI, DUI injury and felony DUI.

Chudnovsky Law legal services in other languages

Our lawyers provide service in Español, Français, Italian, Portuguese, Hebrew and Amharic:

Avocat Pénaliste

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How to get out of a DUI or DWI?

Skilled DUI lawyers have many ways to get out of a DUI or DWI by identifying reasonable doubts or legal flaws in evidence needed to convict under VC 23152(a). Inaccurate breathalyzer BAC testspolice report errorsvarious medical conditions and improper police procedure can all be used to get out of a DUI in court.

How to fight a DUI charge?

Vehicle code 23152(a) VC requires prosecutors prove that you were driving under the influence beyond a reasonable doubt. There are many blood test inaccuracies and police error defenses that can be used to fight a DUI charge, get evidence suppressed and the DUI dismissed.

“I was arrested for a DUI in LA and a friend told me to call Ms Chudnovsky. She gave me a free consult and took the time to carefully review what happened and explain the different ways they could fight the case. She is really good at listening and putting you at ease. As a professional with a license that could be suspended I was pretty freaked out.

Even though I blew .16 at the DUI checkpoint, she was able to get the charge reduced to dry reckless. I kept my license and she is going to get the charge expunged off my record in a year. Very smart, hard working attorney you’d be fortunate to have represent you.”


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BAC chart: Estimated blood alcohol chart

There are many factors that affect a person’s blood alcohol concentration (BAC) when drinking. The blood alcohol level charts below estimate the BAC effects of drinking based on the person’s: gender, weight and type of drink. Other factors can also affect BAC levels, such as: what food is in your stomach, your liver function and how much water you have consumed.

The California BAC limit for legal driving is:

  • .01% or higher: If you’re under 21 years old or are on DUI probation for a prior DUI conviction
  • .04% or higher if:
    • You are driving a passenger for hire vehicle with a passenger (i.e. Uber, Lyft and taxi drivers) effective 7/1/18, or
    • You hold a commercial driver’s license (CDL). This limit applies whether you are driving a personal or commercial vehicle.
  • .08% or higher: If you’re an adult, 21 years of age or older and hold a standard California driver’s license with no restrictions.

The BAC levels California defined in the charts below are for adults aged 21 years or older that are not commercial license holders:

BAC chart Men
BAC chart Women

The DUI defense strategies outlined here can be used to fight a DUI in all states including: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin and Wyoming.



This information does not constitute legal advice and is not a substitute for individual case consultation and research. No representations are made as to the accuracy of this information and appropriate legal counsel should be consulted before taking any actions.  Contact us for a Free consultation regarding your case to see if Chudnovsky Law is the best DUI defense attorney for you.


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