An arrest is a process, not a result. A DUI arrest usually includes the three steps discussed below. An arrest is a process because officers must gather enough evidence to hold up in court. Since the standard of proof is so high (beyond any reasonable doubt), police officers must gather as much evidence as possible. A shortcoming in any area could create a procedural, substantive, or affirmative defense.
A Marietta criminal defense lawyer leverages these defenses during trial, or more likely during pretrial settlement negotiations, to obtain the best possible result under the circumstances. This result could be a complete dismissal of charges, a plea to a lesser included offense, such as reckless driving, a lighter sentence, like deferred disposition instead of regular probation, or a not-guilty verdict at trial.
Stage One: The Initial Stop and DUI Investigation
A law enforcement contact is the first step in any DUI or other criminal arrest. Nine times out of ten, this law enforcement contact is a traffic stop.
Usually, the traffic stop is completely unrelated to DUI. Instead, officers rely on moving or non-moving traffic violations, such as speeding or an expired tag, to detain motorists. These infractions are often very ticky tack, but courts have consistently held that the most ticky-tack offense, or even a reasonable belief that the driver committed an offense, justifies a legal stop.
However, the driver must commit an offense. That’s the “reasonable” element of the reasonable suspicion requirement. Officers may only detain motorists based on an evidence-based hunch of criminal activity. The order is significant. If Officer Lou suspects Barney may be driving while intoxicated and follows Barney until he commits a traffic violation, Lou profiled Barney.
Lack of reasonable suspicion is a procedural defense that undermines the most well put-together criminal case. A well-constructed house built on a shaky foundation won’t stand.
Next, during DUI investigations, officers usually check for physical symptoms, such as an odor of alcohol, bloodshot eyes, and slow reflexes. They generally interrogate suspects as well. These interrogations usually focus on previous alcohol consumption.
These physical examinations and verbal interrogations often violate the Fifth Amendment. Once custodial interrogation begins, if the suspect reasonably believes his/her answer may be incriminating, the right to remain silent applies. This right includes both physical silence (refusing to submit to a medical examination) and verbal silence (refusing to answer questions).
If officers fail to respect constitutional rights during arrests, any evidence they obtain later is fruit from a poisonous tree and inadmissible in court.
Stage Two: Field Sobriety Tests and Common Defense Issues
After a brief investigation, officers usually tell DUI suspects to step out of the car. Suspects must step out of the car and obey other such basic commands. But suspects may refuse to perform the three approved field sobriety tests. FST performance is basically a nonverbal interrogation that’s protected by the Fifth Amendment, as outlined above.
- Horizontal Gaze Nystagmus: Officers almost always lead with the DUI eye test because, to many suspects, it feels like a safety test. Therefore, the compliance rate is higher. The follow-my-finger test accurately diagnoses nystagmus. But intoxication isn’t the only cause, or even the leading case, of nystagmus.
- One-Leg Stand: The compliance rate drops dramatically when physical tests begin. The accuracy rate drops off as well. Instead of concentrating on the tests, these defendant know they’re in trouble. The stress affects their concentration and physical abilities. On top of that, the OLS is almost impossible to perform if the subject has even a slight mobility impairment.
- Heel-to-Toe Walk: By this time, mental and physical fatigue is a major factor. In court, prosecutors must prove that intoxication, not intoxication combined with fatigue or anything else, caused the complete loss of mental or physical faculties. If the mixture was 99 percent intoxication and 1 percent fatigue, the defendant is not guilty as a matter of law.
These flaws often aren’t serious in chemical test cases. In these matters, the field tests must only establish probable cause of intoxication. That’s a much lower standard than beyond any reasonable doubt. An officer’s subjective opinion that the defendant “failed” the test usually holds up in court, at least for probable cause purposes.
However, in non-test cases, the FST evidence must establish guilt beyond any reasonable doubt. Because this standard is so much higher and because the FSTs have reliability issues, the non-test conviction rate is much lower than the chemical test conviction rate.
Stage Three: Chemical Testing and Affirmative DUI Defenses
Chemical tests, such as breath, blood, or urine tests, are almost absolute proof of intoxication, at least beyond a reasonable doubt. But a positive test doesn’t guarantee a conviction. A Marietta criminal defense lawyer can raise affirmative defenses that challenge the reliability, legality, or interpretation of these tests.
One common defense is improper administration of the test. Police officers aren’t scientists. Nevertheless, they must conduct chemical tests according to scientific standards.
If the officer failed to follow required protocols (such as observing the subject for a required period before a breath test or using improper testing techniques) the results may be unreliable and excludable.
Improper calibration or mechanical malfunction is another possible affirmative defense. Breathalyzer and other testing devices must be regularly maintained and calibrated. If records show that the equipment was outdated, poorly maintained, or not calibrated correctly, test results may or may not be accurate. The same defense applies if a Marietta criminal defense attorney studies a device and finds any flaw whatsoever, such as an underpowered sensor.
Chain of custody issues often affect blood or urine tests. The prosecution must demonstrate that the sample was properly collected, labeled, stored, and transported. Any gaps or errors in the chain of custody raise concerns about contamination, tampering, or identification.
A defendant may also argue that medical or physiological conditions affected the test results. Certain conditions, such as acid reflux, diabetes, or certain medications, can produce falsely elevated readings or interfere with the testing process. This possible affirmative defense applies to all chemical tests, not just blood tests.
Another defense which applies to all chemical tests is lack of probable cause or unlawful testing. If the subject refused to perform one or more field tests, prosecutors must use much weaker reasonable suspicion evidence to establish probable cause.
DUI arrest issues give rise to criminal defenses in court. For a free consultation with an experienced Marietta criminal defense attorney, contact The Phillips Law Firm, LLC. We routinely handle matters in Cobb County and nearby jurisdictions.
