IOWA CITY — The City of Iowa City is one step closer to hiring its next police chief.The city’s civil service commission on Thursday unanimously certified the hiring of Lt. Dustin Liston of the El Paso (Texas) Police Department. City Manager Geoff Fruin named Liston as his pick to be the next police chief last week.In his letter recommending the hiring of Liston, Fruin cited Liston’s experience working with a diverse population in a college community.