DUI cases involve a lot of moving parts. While most people believe that their case is open-and-shut, even in cases where they were not guilty or driving recklessly, the fact is that the entire case hinges on a few procedures or pieces of evidence. If a procedure was handled incorrectly, it puts the entire case into question—and maximizes your chance for acquittal or dismissal.
Before we get into the different ways you could fight your DUI, we need to say this: these are not buttons that you push or levers to pull. Law is a complex process that combines people and bureaucracy in complicated ways. Having an experienced attorney by your side will ensure the success of these strategies. Even highly-skilled attorneys know better than to represent themselves in court—so do yourself a favor and call a DUI attorney.
Read below for the 7 most common DUI defenses available to defendants.
Challenging the Breathalyzer Results
So your breath test was well above the legal limit. Pretty clear that you're going to lose your case, right? Wrong. Breathalyzers are well-known in law enforcement for not being infallible. Defective parts or lack of maintenance can inflate results and give inaccurately high readings. Conditions like diabetes often trigger false positives due to the presence of an alcohol-like by-product in the breath.
If you can prove that your breathalyzer was not maintained often enough to give trustworthy results or the arresting officer was not using it properly, then it would put the results of the test into question—meaning it's less effective against you in court.
Challenging the Blood Test Results
Similar kinds of challenges can be levied against blood test results. For blood tests, the integrity of results is important enough to warrant "chain-of-custody" procedures. These procedures strictly dictate how to collect, handle, and store blood samples for testing. If there's enough breakdown or ambiguity in the chain of custody, then the court may exclude the results of the blood test from your trial.
In addition, challenging the qualifications of the testing lab might yield the same result. Unqualified testers or old equipment can't be trusted to administer accurate blood alcohol content tests. If the police's testing lab has records of their equipment maintenance or staff qualifications, an attorney might be able to get your blood test results thrown out.
Question the Use of Field Sobriety Tests
Field sobriety tests have been shown to be inaccurate time and time again. Reciting the alphabet backwards or standing on one leg are not reliable ways to test for drunkenness—but it doesn't stop some police officers from employing it during DUI stops. Their vulnerability to dispute makes field sobriety test results a prime target for your attorney.
You likely failed your field sobriety test due to something other than drinking if:
- You're overweight
- You were on uneven terrain
- You have poor coordination
- The weather was bad that day
- You were physically or mentally exhausted
If any of the above matches your situation, your attorney should object to using the field sobriety test as evidence against you.
Challenge the Legality of the Stop
Police stops that aren't at a DUI checkpoint need to respect your right to privacy (while allowing law enforcement to do their job). As a result, officers operate by the principle of "reasonable suspicion," meaning they need a reason to warrant pulling you over. Once they've pulled you over, they have the right to conduct a mini-investigation with limited parameters (including asking you to perform a field sobriety test). If their observation of your behavior, speech, or smell warrants an arrest, you'll be taken in and likely charged with DUI.
As a result, you can threaten the entire case by challenging whether or not the officer was legally able to stop you. Keep in mind that this strategy is not effective most of the time—police officers have broad powers when it comes to pulling drivers over.
If you were doing the following, your officer had the right to pull you over:
- Headlight or taillight were out
- Speeding or weaving in traffic
- Excessively tailgating the next car
- Running a light
- Driving too slowly
Challenge the Legality of the DUI Checkpoint
DUI checkpoints operate by different laws than spontaneous police stops. For one, they're allowed to stop any car just for driving through that street—so reasonable suspicion isn't an issue. However, DUI checkpoints still need to follow certain rules.
To be considered legal, a checkpoint must:
- Stop cars uniformly (not at random)
- Provide adequate notice of the DUI stop beforehand
- Be respectful of privacy rights
- Be clearly official, planned, and authorized (to prevent arbitrary checkpoints)
Your attorney will be clear on your state's laws regarding DUI checkpoints. He or she will be able to challenge the legality of the stop if it might prove beneficial to your case.
Challenge the Reasonable Suspicion that You Were Drunk
Earlier we mentioned the importance of "reasonable suspicion," and it applies to both pulling you over and arresting you. If you or your attorney can prove that there was no warrant to suspect you of DUI, then the odds of dismissing your case or convincing the prosecutor to drop charges is far more likely.
The key is proving a more likely explanation for your state or behavior:
- Certain medical conditions (like vertigo or diabetes)
- Medication side effects
- Over-the-counter products (e.g. mouthwash)
- Footage that doesn't match the police report
Mouthwash and other household products that contain alcohol might create a false positive for a breathalyzer test, leading to a wrongful arrest. Keep in mind that some of these may not actually get you off the hook—it may just drop your charge to "reckless driving," which has more lenient penalties.
Cite the Failure to Mirandize You
Miranda rights are the rights that police are required to recite to you prior to questioning you for the sake of gathering testimony. Constitutionally, you are not required to say anything that would incriminate you (which is why your Miranda rights are important to hear).
Any testimony or evidence gathered from you before your Miranda rights were recited—but after your arrest—is invalid in court and cannot be used against you. Keep in mind, you do not need to hear your Miranda rights in order to be arrested. It only matters when you're being
questioned after or during your arrest. Citing the failure to Mirandize, if it's capitalized on early enough, can get your entire case dismissed.
Like we said before, find a local DUI attorney as soon as possible. The best possible chance for your acquittal or dismissal is entrusting these strategies to the hands of a seasoned legal professional.