FILE - In this Feb. 19, 2014, file photo, Franklin County Prosecutor Ron O'Brien discusses central Ohio homicide cases during a Columbus, Ohio, news conference. Because two dozen death row inmates in Ohio now have scheduled execution dates, but the state has been unable so far to obtain lethal drugs used in past executions, O'Brien says he'd like state officials to consider nitrogen gas, approved by Oklahoma in April. (AP Photo/Andrew Welsh-Huggins, File)