When it comes to any criminal law matter, the defendant will remain innocent until — and only if — the prosecution proves that the defendant is guilty beyond a reasonable doubt. The burden of proof, therefore, lies in the hands of the prosecution. During the criminal law process, the defendant will have every opportunity to cast doubt on the prosecution’s interpretation of the facts.

In a DUI trial, one of the best ways for a defendant to “cast doubt” on the prosecution’s case is to attack the allegedly “hard” evidence that the prosecution plans to use for the purpose of conviction.

Strategies for challenging different types of evidence in a DUI case

Here are a few types of evidence and strategies for challenging them:

The police officer’s account of what happened: The police officer who arrested the defendant will usually have a story about how the defendant was driving before pulling the defendant over, how the defendant looked, appeared, talked and walked. Courts are prone to believe the police officer’s account of the facts, but a skilled defense attorney may be able to cross-examine the officer to reveal inconsistencies in the story. Video evidence might also contradict the officer’s version of the facts.

Blood alcohol test results: No matter what kind of testing method is used to determine a defendant’s blood-alcohol level, it has the potential for producing flawed and inaccurate results. A Breathalyzer test device could be improperly calibrated, poorly maintained or broken. Blood and urine samples might be taken in the wrong way or poorly handled during the testing process in the lab. Also, the timing of these tests could render completely flawed results.

Field sobriety test results: Field sobriety test results are also prone to being inaccurate. An officer might administer this test in a way that doesn’t follow protocol, or maybe the defendant was dealing with a health condition — having nothing to do with being intoxicated — that caused the defendant to fail the test.

Explore your DUI defense options

By learning about various DUI defense strategies and the law in the context of the unique facts of your DUI case, you can explore all the options available for your defense to select the most appropriate one for your needs.