The latest unrest comes after an off-duty police officer killed 18-year-old Vonderrit D. Myers, who authorities say fired three times in the encounter.
Thomas Jackson said he was sorry to the victim's family and to anyone who felt their right to "peacefully protest" had not been protected by authorities.
The Department of Justice says it will begin a review of police department procedures in Beavercreek, Ohio, where officers fatally shot a 22-year-old black man at a Wal-Mart store.