DUI Evidence: What Defendants Need To Know
Evidence is an important aspect of almost any criminal matter. However, it may be the most important aspect of a driving under the influence (DUI) case. Evidence can be plentiful after a traffic stop, but the value of the evidence depends on the way it was obtained and processed. With so much riding on evidence, it's important to understand some common forms of DUI evidence and how it should be challenged.
The Traffic Stop
Nearly all DUI arrests begin with a traffic stop. Evidence also begins to accumulate with the stop. Law enforcement cannot stop a vehicle because they saw the vehicle leave a well-known drinking establishment or music festival or because it's a traditional drinking holiday like New Year's Eve. They must have a legitimate reason to stop the vehicle based on illegal or suspicious activity by the driver. However, the reason for the stop doesn't necessarily need to be connected to DUI. Many stops occur because the subject failed to obey a traffic law, was not wearing a seatbelt, or had equipment issues with their vehicle.
Blood Alcohol Concentration (BAC)
The level of expelled alcohol molecules can be, theoretically, measured in the expelled breath of a suspect. However, the portable field unit results may not be accurate enough to stand up in court. In many cases, the results of the field BAC are verified with a larger measuring device at the police station. The evidence obtained from any type of BAC device is only as good as the device. Your criminal defense lawyer will challenge the validity of the BAC results by questioning the calibration schedule and the training of the administrator.
Field Sobriety Testing
In most cases, field sobriety tests are used to screen drivers for further testing. That is chiefly because the results of such tests are unreliable. Testing candidates may not "pass" a test because of several medical and neurological conditions rather than intoxication. All the field sobriety tests measure vague metrics like how well the subject can follow directions.
However, those with hearing problems, language differences, or neurological disorders may not pass a field sobriety test. Other tests call for performing physical moves like standing on one leg, walking in a line, and following a pen light. Subjects with physical afflictions may be unable to perform and pass such tests.
Your criminal defense lawyer can tell you about the evidence the state has against you and how easily that evidence can be challenged. Reach out to a DUI attorney for more information.
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