The Iowa State Patrol says Shipley was arrested around 8 p.m. Wednesday in Sigourney. Patrol Capt. Mike Winter told KCRG-TV in Cedar Rapids that a trooper pulled over a vehicle on a minor violation.
Winter says the trooper found Shipley behind the wheel, and he appeared to be driving under the influence of alcohol.
Shipley was arrested for OWI and taken to the Keokuk County jail, where he was later released on his own recognizance.
Winter says Washington County will be prosecuting the case to avoid any potential conflict of interest.
Shipley on Thursday released a statement saying he's "fully confident" that he'll be vindicated.