Article source: Liberty Law Center, CO
A DUI charge can lead to severe penalties, but a conviction isn’t inevitable. The outcome may depend on challenging the prosecution’s evidence at every stage, from the legality of the initial traffic stop to the scientific accuracy of chemical tests. A strategic, methodical defense is crucial for identifying procedural errors and weaknesses to achieve a dismissal, reduction of charges, or acquittal.
This practical guide outlines the essential steps and common legal strategies for challenging DUI charges, emphasizing the critical importance of a meticulous, detail-oriented approach.
Understanding the Legal Foundation of a DUI Case
Before building a defense, it’s crucial to understand what the prosecution must prove. For instance, in Colorado, a driver can be charged with DUI in several ways: for driving while “under the influence” of alcohol or drugs, or for driving with a blood alcohol concentration (BAC) of 0.08% or greater (known as DUI per se). For a conviction, the state must establish these elements beyond a reasonable doubt, and each presents a unique avenue for defense.
Hence, navigating this complex legal terrain typically requires the skill of a specialized DUI defense lawyer in Colorado Springs or similar locations, who can identify procedural errors and scientific inaccuracies that form the backbone of a successful defense.
The Cornerstone of DUI Defenses: Challenging the Traffic Stop
Every DUI investigation begins with a traffic stop, and its legality is the first and often most powerful line of defense. Laws like the Fourth Amendment in the United States protect individuals from unreasonable searches and seizures, meaning an officer must have reasonable suspicion of a traffic violation or criminal activity to stop and search a vehicle lawfully. Here’s how to challenge the traffic stop:
Questioning Reasonable Suspicion
A defense attorney will meticulously review the officer’s stated reason for the stop. Erratic driving, such as weaving or speeding, can have innocent explanations like potential distractions, fatigue, or avoiding road hazards. If the officer can’t articulate a valid reason, any evidence gathered after the stop, including field sobriety tests and BAC results, may be suppressed and deemed inadmissible in court.
Checkpoint Compliance
Sobriety checkpoints are legal but must adhere to strict guidelines, including advance public notice and a neutral, predetermined formula for stopping vehicles. A DUI checkpoint that violates these standards can render any arrests made there invalid.
Scrutinizing Field Evidence: Sobriety Tests and Initial Observations
After a stop, officers rely on the following to establish probable cause for an arrest:
Unreliable Field Sobriety Tests
It’s believed that standardized field sobriety tests (SFSTs) aren’t 100% accurate even under ideal conditions. Criminal defense attorneys can argue that a client’s performance was affected by factors unrelated to impairment, such as nervousness, medical conditions, poor lighting, uneven pavement, or inappropriate footwear.
Innocent Explanations for Physical Signs
Officers often cite bloodshot eyes, slurred speech, or the smell of alcohol as signs of impairment. A strong defense can offer alternative explanations, such as allergies, fatigue, a cold, ongoing medical treatments, or having consumed a single drink within a legal blood alcohol level. A thorough review of dash cam footage may also capture these conditions or expose irregularities in police procedures that formed the officer’s conclusions.
Attacking the Scientific Evidence: Chemical Test Inaccuracies
Chemical testing of breath, blood sample, or urine are considered objective evidence, but they’re not infallible. Challenging their accuracy is a central pillar of DUI defense. Here’s how:
Breathalyzer Test Errors
Breath test devices estimate BAC indirectly and are prone to error. Common challenges include:
Mouth Alcohol
Residual alcohol from recent drinking, burping, mouthwash, or medical conditions like GERD or acid reflux can inflate readings.
Calibration and Maintenance
Machines require regular, certified calibration. Failure to produce maintenance records can cast doubt on results.
Radio Frequency Interference (RFI)
Emissions from police radios, cell phones, or other electronic equipment can cause false high readings.
Physiological Conditions
Individuals on high-protein, low-carbohydrate diets (e.g., keto) or with diabetes may enter ketosis, where the body produces isopropyl alcohol, which breathalyzers cannot distinguish from ethanol.
Blood Test Vulnerabilities
While deemed more reliable, blood tests involve a chain of custody from draw to analysis at a crime lab. Any break in this chain or failure to follow strict protocols can compromise the sample. Criminal defense tactics include filing a “blood split motion” to test the sample for fermentation or contamination independently.
The Rising BAC Defense
Alcohol absorbs into the bloodstream over time. It’s scientifically possible for a driver’s blood-alcohol concentration (BAC) to have been below the legal limit while driving but to have risen above it by the time testing occurs at the station.
Leveraging Procedural Errors and Violations of Rights
Law enforcement must follow specific procedures during a DUI investigation. Deviations can provide substantial grounds for defense. These include:
Miranda Rights Missteps
While not required during the initial investigation, police must read Miranda warnings to a suspect once they are in custody and subject to interrogation. Failure to do so can result in any subsequent incriminating statements being suppressed.
Lack of Probable Cause for Arrest
An officer must have probable cause or a reasonable belief that a crime was committed to make an arrest. If the basis for arrest was solely poor performance on improperly administered field tests or innocent physical signs, the arrest itself may be unlawful.
Conclusion
A DUI charge carries severe penalties, including jail time, hefty fines, driver’s license suspension, and a permanent criminal record. However, the evidence is rarely as incontrovertible as it may initially seem. From an illegal traffic stop and unreliable field tests to faulty chemical analysis and procedural violations, multiple points of attack exist.
Successfully navigating these complexities demands an understanding of nuanced legal standards, forensic science, and local court procedures. By keeping the information mentioned above in mind, one can mitigate consequences, protect their driving privileges, and secure future stability.
