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4 types of evidence that contribute to an Iowa OWI case

On Behalf of | Jul 27, 2023 | Drunk Driving |

For the Iowa criminal courts to convict someone of an operating while intoxicated (OWI) offense, there needs to be compelling evidence that can convince a judge or jury beyond a reasonable doubt that someone has broken the law. Police officers will often start trying to gather that evidence as soon as they pull someone over or respond to a report of a collision.

Drivers may not realize how the little mistakes they make during an interaction with a police officer might eventually result in them facing OWI charges and needing to deal with a lifelong criminal record. It’s important for motorists, therefore, to understand that police officers may be trying to gather during an OWI stop.

Video footage of questionable driving

Police officers will often follow someone for multiple blocks to capture dashcam footage of someone swerving across the road or behaving in an erratic manner while at the wheel. That video footage can then help justify the traffic stop and the possible future decision the officer makes to arrest someone for drunk driving.


Many drivers will admit that they have possibly had too much to drink when an officer pulls them over. Some people think that being honest and friendly could be enough to help them talk their way out of an arrest. Admitting to having alcohol, especially admitting to drinking enough to cause impairment, can end up included in an officer’s testimony or even captured by body camera footage.

Field sobriety test results

There are several standardized field sobriety tests that officers can administer to drivers at the side of the road to determine if they are likely under the influence of alcohol. Depending on someone’s performance on those tests, officers may be in a position to demand additional testing that could further implicate the motorist.

Blood alcohol test result

Officers may perform breath tests at the side of the road during a traffic stop or even after a car crash. In some cases, such as when a motorist requires transportation to a medical facility, there may be a blood test performed instead. Chemical evidence of impairment may eventually result in someone’s prosecution.

There can be issues with the accuracy or validity of each of these types of evidence. Understanding how the state builds a case may help those hoping to fight back against a pending Iowa OWI charge.

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