How to Defend Against a DUI Charge Based on Erratic Driving in California

In California, erratic driving is often used as a key indicator of impairment in DUI cases. If law enforcement observes a driver engaging in suspicious or unsafe driving behavior, it may lead to a DUI stop and subsequent charges. However, erratic driving alone does not necessarily mean that a driver is under the influence of alcohol or drugs. There are several strategies that can be employed to defend against a DUI charge based on erratic driving. This article explores these defense strategies, including how to challenge the evidence and the role of mitigating factors.

Erratic driving refers to behavior that deviates from normal or safe driving practices. Common examples include:

• Weaving Between Lanes: Frequent lane changes or drifting without signaling.
• Excessive Speeding or Slow Driving: Driving significantly above or below the speed limit.
• Tailgating: Following other vehicles too closely.
• Failure to Obey Traffic Signals: Running red lights or failing to stop at stop signs.

While such behavior may prompt a traffic stop and DUI investigation, it is not definitive proof of impairment. Many factors, including mechanical issues or medical conditions, can contribute to erratic driving without indicating intoxication.

The first step in defending against a DUI charge is to scrutinize the officer’s observations of erratic driving:

• Accuracy of Observations: The defense can argue that the officer’s interpretation of the driving behavior was inaccurate. For example, lane changes might have been made safely but perceived as erratic by the officer.
• Environmental Factors: Factors such as poor road conditions, weather, or other external elements may have contributed to the observed behavior. If the conditions were unfavorable, they might have impacted the driving without implying impairment.

The credibility and training of the officer who observed the erratic driving are crucial:

• Officer Training and Experience: The defense can investigate whether the officer was properly trained to recognize signs of impairment and whether their observations were consistent with their training.
• Bias and Motivation: If there is evidence of bias or motivation on the part of the officer, such as prior conflicts with the driver or an aggressive approach, it can be used to question the reliability of their observations.

If field sobriety tests were conducted following the erratic driving, their results may be used to support the DUI charge. Defending against these results involves:

• Test Conditions: Field sobriety tests must be administered under standardized conditions. Factors such as uneven ground, poor lighting, or distractions can affect performance. If the tests were not conducted under optimal conditions, their reliability can be challenged.
• Physical Limitations: Some individuals may have physical limitations or medical conditions that affect their ability to perform the tests accurately. The defense can argue that the driver’s performance was impacted by factors unrelated to impairment.

Chemical tests, such as breathalyzer or blood tests, provide objective evidence of BAC or drug presence. Defending against these results involves:

• Accuracy of Testing Devices: Breathalyzers must be calibrated and maintained regularly. If there is evidence that the device used was not properly calibrated or maintained, the test results can be challenged.
• Timing of Testing: The timing of chemical tests is critical. If there was a significant delay between the driving incident and the testing, the BAC levels may not accurately reflect the driver’s condition at the time of driving.

Alternative explanations for erratic driving can undermine the prosecution’s case:

• Medical Conditions: Certain medical conditions, such as a seizure disorder or diabetic episode, can cause symptoms that may be mistaken for impairment. Medical records or expert testimony can be used to explain the driving behavior.
• Mechanical Issues: Mechanical issues with the vehicle, such as faulty steering or brake problems, might have contributed to the erratic driving. Evidence of vehicle problems can be used to support this argument.

The legality of the traffic stop itself can be challenged:

• Reasonable Suspicion: Officers must have reasonable suspicion or probable cause to initiate a traffic stop. If the stop was made based on a mistaken belief or without valid grounds, the evidence obtained from the stop may be challenged.
• Violation of Rights: If the driver’s constitutional rights were violated during the stop, such as an unlawful search or interrogation, the evidence obtained may be inadmissible in court.

Defending against a DUI charge based on erratic driving involves a thorough examination of the evidence, including the officer’s observations, field sobriety and chemical test results, and potential alternative explanations for the driving behavior. By challenging the accuracy of the observations, questioning the credibility of the officer, and presenting alternative explanations, defendants can build a strong case to contest the DUI charges. Consulting with an experienced DUI attorney is essential for navigating these defenses and ensuring that your rights are protected throughout the legal process.