Cleveland Mayor Frank Jackson said the decision will put a layer of separation between the police and the investigation.
"That's part of our attempt to demonstrate transparency and having an outcome that will not be tainted by people believing that the police department is investigating itself," Jackson told reporters Sunday afternoon.
Taking over the investigation will be Sheriff's Department Chief Clifford Pinkney.
Jackson said he didn't ask the state to take over because he disagreed with findings from an earlier state investigation into the Nov. 2012 fatal chase and shooting by police.
"I don't think the state attorney general handled the East Cleveland shooting properly," he said. "It wasn't done in a way that I think was -- that gave me confidence that this would have been done properly."
