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How Can a DWI Test Be Challenged?

Posted on February 24, 2023 in Drunk Driving Charges,DUI,Field Sobriety Tests

If you get arrested for driving while intoxicated (DWI) in Arizona, you could face severe penalties. A DWI conviction could result in fines, jail time, and the loss or suspension of your driving privileges. A DWI and DUI defense attorney in Tempe will look for ways to poke holes in the prosecutor’s case against you, including challenging a DWI test.

What Is the Difference Between DWI and DUI in Arizona?

Although DUI and DWI are similar, they have differences on a statutory level. DUI refers to driving under the influence, while DWI is driving while intoxicated. A DUI can refer to the influence of both drugs and/or alcohol, but DWI only refers to alcohol. 

Finding a defendant guilty of DUI does not necessarily require proof that the driver’s blood alcohol concentration (BAC) level was at or above the legal limit of 0.08 percent. A DUI charge could be brought against a driver even with a lesser BAC if it appears that his or her faculties are impaired. A DWI conviction, on the other hand, requires proof of a BAC of 0.08 percent or greater. This means the prosecution will need to submit evidence in the form of a DWI test.

Challenging Chemical Drug and Alcohol Test Results 

By law, all drivers in Arizona give their implied consent to chemical drug and alcohol testing when they obtain their licenses. Refusing to cooperate with these tests will result in automatic driver’s license suspension for one year – even if you were not under the influence of drugs or alcohol. 

Chemical tests can take the form of breath, blood or urine tests that check for drugs and/or alcohol. A Breathalyzer test is most common at traffic stops. It analyzes the amount of alcohol or ethanol content in a driver’s blood. If a Breathalyzer reading shows any amount of alcohol present, the driver could be arrested for an alleged DUI. 

Many things could go wrong during a chemical drug or alcohol test that make the results inaccurate. The test may be administered incorrectly, for example, or the machine may have been poorly maintained. Something else may have led to a BAC readout besides alcohol. Any of these issues could be brought forth in a case to cast doubt on the prosecutor’s DWI test evidence.

Field Sobriety Tests Are Notoriously Inaccurate

A field sobriety test is conducted by a law enforcement officer during a traffic stop. It is a series of physical tests intended to identify an impaired driver, such as asking a driver to stand on one leg, walk in a straight line, or follow light or an object visually. The police officer will judge the driver’s performance on these tests, as well as the driver’s cooperation and ability to follow directions. 

Based on the officer’s personal opinion of how the driver did on the field sobriety test, the officer could decide to make an arrest. Field sobriety tests are known for being biased and inaccurate. In addition to being contingent upon an officer’s personal opinions, there are many reasons besides intoxication that a driver could fail a field sobriety test. A foreign driver may not understand the language in which the test was given, for example, or a pre-existing injury could make standing on one leg impossible. 

If a DWI or DUI case involves evidence against you in the form of a chemical or field sobriety test that you allegedly failed, a criminal defense attorney can work to prove that these test results are inaccurate and therefore should be deemed inadmissible in court. This could lead to the case against you being thrown out or a case acquittal at trial. If your case involves evidence in the form of either type of DWI test, contact an attorney to help you fight these charges.

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