First Offense OWI in Des Moines

How Iowa OWI Cases Are Built & Where They Can Be Challenged

Most OWI arrests begin with a traffic stop. The officer uses three standardized field sobriety tests: the HGN (horizontal gaze nystagmus), walk-and-turn, and one-leg stand, along with a preliminary breath test to establish probable cause. The PBT result isn’t admissible at trial, but it drives the decision to arrest and triggers the implied consent process.

Once you’re in custody, the officer reads the implied consent advisory and requests a Datamaster breath test at the station. Both the test result and a refusal carry license consequences. What many defendants don’t know is that Iowa Code 804.20 gives you the right to contact an attorney, a family member, or a friend before submitting to chemical testing. If that right was denied or not adequately provided, it becomes a defense issue in your case.

Several legal rules create opportunities to challenge evidence:

• The 2-hour rule: A chemical test taken within two hours of driving is presumed to reflect what was in your system while operating. Tests administered outside that window don’t carry the same presumption under Iowa Code 321J.2(12).
• Field sobriety tests: These can be challenged based on improper administration, medical conditions that affect performance, or failure to follow standardized protocols.
• Implied consent timing: Under Iowa Code 321J.6, the officer must offer a chemical test within two hours of the preliminary breath test or arrest, whichever comes first. Failure to meet that requirement can void the license revocation.
• Probable cause for the stop: If the officer lacked legal justification for the initial stop or made procedural errors during the investigation, the resulting evidence may be subject to suppression. That may lead to a dismissal or charge reduction.

Iowa Deferred Judgment for First-Offense OWI

A deferred judgment allows an eligible defendant to plead guilty while the court withholds a formal conviction and places the defendant on probation instead. If probation is completed successfully, the charge is discharged and no conviction appears on the public criminal record. For first-time defendants, this is often the most consequential option available.

Eligibility is specific. You qualify only if you have no prior OWI conviction and no prior deferred judgment, your BAC was under 0.15, you didn’t refuse the chemical test, and your OWI didn’t cause bodily injury to another person. All four conditions must be met.

There are limits worth understanding. A deferred judgment still counts as a prior offense if you’re ever charged with OWI again. It doesn’t eliminate the Iowa DOT’s administrative license consequences, including revocation and any ignition interlock requirements. Conditions typically include probation, a 12-hour drinking drivers course, substance abuse evaluation and treatment, and payment of civil penalties. Violating probation can result in the withheld conviction being entered, exposing you to full criminal penalties.