An Analysis of OWI Arrests and Convictions in Iowa, 2011

The primary goal of the project was to document the demographic profile of OWI offenders in Iowa. The study is based on both aggregate and case-level data. The case level data produced a final sample of 118,675 OWI convictions. That occurred from 2000 through 2009. The great majority of convicted offenders were White males. From 2000 through 2009 the percentage of convictions received by women increased by 34%. Defendants’ average age of was 30 years old, and the age cohorts of 15 to 24, 25 to 34, and 34 to 45 were overrepresented among convicted offenders. Whites were underrepresented among OWI defendants. African Americans, Hispanics and Native Americans were overrepresented. From 2000 through 2009, the percentage of aggravated misdemeanor felony OWI convictions received by Hispanics and African Americans increased significantly. The percentage of OWI convictions received by women and African Americans increased significantly after implementation of the .08 BAC law. We did not find convincing evidence of a direct relationship between enforcement trends and the alcohol related traffic fatalities (ARTFs). However, the ten year Iowa conviction trends did provide evidence of a conviction lag effect on Iowa’s ARTFs. The research findings established the basis for a phase two project that would assess the efficacy of OWI sentencing practices in Iowa.