An investigating committee shall have the chair and vice chair who: are appointed by the resolution that establishes the investigating committee; or if the resolution does not appoint these officers, are elected by affirmative vote of a majority of all of the members of the investigating committee. The rules of an investigating committee shall provide for the selection of a presiding officer to act if the chair and vice chair are absent or unable to act. At a hearing of an investigating committee, the presiding officer shall be: the chair of the investigating committee; if the chair is absent or otherwise unable to preside, the vice chair; or if the chair and vice chair are absent or otherwise unable to preside, the individual who is selected under the rules of the investigating committee. At a hearing, the presiding officer: shall examine the witnesses or supervise the examination by any other member of the investigating committee or by staff who are authorized to examine witnesses; and may direct a witness to answer a relevant question or to provide a relevant book, document, or paper.