CINCINNATI (AP) — A presidential task force charged with examining ways to improve police-community relations heard testimony on Friday from researchers, law enforcement representatives and others with suggestions for strengthening policies and oversight of police use of force. The issue led off two days of sessions by the Task Force on 21st Century Policing formed in December amid a continuing outcry over police use of force in minority communities after the killings in Ferguson, Missouri, and other cities, including Cleveland and the Dayton suburb of Beavercreek in Ohio. Charles Ramsey, Philadelphia's police commissioner who also served with the Washington D.C.