One of the most important non-legislative functions of the U. S Congress is the power to investigate. This power is usually delegated to committees—either standing committees, special committees set for a specific 21 purpose, or joint committees consisted of members of both houses. 22 Investigations are held to gather information on the need for future legislation, to test the effectiveness of laws already passed, to inquire into the qualifications and performance of members and officials of the other branches, and in rare occasions, to lay the 23 groundwork for impeachment proceedings. Frequently, committees rely outside experts to assist in conducting investigative hearings 24 and to make out detailed studies of issues. 25 There are important corollaries to the investigative power. One is the power to publicize investigations and its results. Most 26 committee hearings are open to public and are reported 27 widely in the mass media. Congressional investigations nevertheless represent one important tool available to lawmakers 28 to inform the citizenry and to arouse public interests in national issues. 29 Congressional committees also have the power to compel testimony from unwilling witnesses, and to cite for contempt of Congress witnesses who refuse to testify and for perjury of these who give false testimony. 30