The Two Hour Rule For Testing DUI/OWI

scheetzlaw - DUI lawyer Cedar Rapids - Criminal Defense - two hour ruleDrinking and driving can carry serious consequences. The interaction between officer and arrestee leading up to an operating while intoxicated (OWI) charge is complex and can be confusing. See either of my two previous posts, “Stopped by Police, Suspected Drunk Driving?” or “Drunk Driving Laws in Iowa Explained” for a breakdown of the complexities.  These articles shed light on some OWI basics, but here we specifically clarify the “Two Hour Rule” portion of the law.


In sum, the rule provides a two hour window for officers to request chemical testing of your blood, breath or urine for establishing your blood alcohol content (BAC) after suspected drunk driving. It sounds straightforward enough, but there are actually quite a few moving parts to consider.  

In the course of stopping a suspected drunk driver, the police officer can first ask for a preliminary screening test.  The results of this test are usually not admissible in court as evidence.  Instead, the officer uses the preliminary test in conjunction with the circumstances the officer observes to determine whether to arrest the driver or request chemical testing. If the officer determines to move forward, they have two hours from either the arrest or the sample request to collect the blood, breath or urine sample.

Iowa is an implied consent state, meaning the driver is required to submit to blood, breath or urine tests when requested by the officer.  Refusal of a breath or urine test within the two hour period carries a civil penalty of having your license immediately revoked for one year, two years for subsequent violations.

Any BAC results collected within the two hour window are presumed to show the alcohol concentration at the time the driver was operating the vehicle.


The officer determines which test to employ.  However, if the officer first requests a blood test and the driver denies, this does not constitute refusal and the officer must choose either a breath or urine test. 

If the officer elects for a breath test, the officer must observe the arrestee for 15-20 minutes prior to administering the test.  This requirement ensures that no food or drink has been put in his/her mouth and any residual alcohol in the mouth has dissipated so as not to inflate any results.

If the two hour window has passed, no test is required and refusal of any requested test will not result in license revocation penalties. 

It is also important to note that the constitutional protection against self-incrimination does NOT create a protection for refusal to take a BAC test. 

Why It’s Important To Hire An Attorney

Facing DUI/OWI charges or other criminal offenses can be daunting, especially because the repercussions can be severe.  You should always be as prepared as possible and consulting a seasoned criminal defense lawyer is one of the best steps you can take. The Law Office of Ray Scheetz has the knowledge, skill and experience in handling a variety of criminal charges, including OWI offenses. Please contact us if you are in need of legal assistance.


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