The Permanent Subcommittee on Investigations (PSI), stood up in March 1941 as the "Truman Committee," is the oldest subcommittee of the United States Senate Committee on Homeland Security and Governmental Affairs (formerly the Committee on Government Operations). History The Truman Committee (itself successor to the Nye Committee 1934–1936) stood up from March 1941 to 1948, the Investigations Subcommittee of the Committee on Expenditures in Executive Departments took over two key aspects of the Truman Committee. First, Investigations Subcommittee took the Truman Committee's investigation of war contracts and procurement of the Hughes XF-11 reconnaissance aircraft and the Hughes H-4 Hercules flying boat (Spruce Goose). Second, the subcommittee also assumed responsibility for the records of the Truman Committee. Under the chairmanship of Homer S. Ferguson of Michigan (1948) and Clyde R. Hoey of North Carolina (1949-1952), the Investigations Subcommittee of the Committee on Expenditures in Executive Departments held hearings on such matters as export control violations, for which Soviet spy William Remington was called in to testify; the trial of Nazi war criminal Ilse Koch; and the Mississippi Democratic Party's sale of postal jobs, which Mississippians from rural areas attested to purchasing. A much larger scandal erupted with the "5 percenters", so-called because these men, including Presidential aide Harry H. Vaughan, were accused of charging a 5% commission for their influence in securing government contracts. A legislative reform as a result of the hearings was a restriction of one year after leaving government employment before an attorney could practice law again before the government. Korean War Atrocities As news of war crimes during the Korean War unfolded, the Subcommittee on Korean War Atrocities was headed by Charles E. Potter, and began an investigation of the abuse and murder of prisoners of war such as forced marches, maltreatments, and the shooting and murdering of prisoners shortly after capture. Joseph McCarthy In the 83rd United States Congress, the subcommittee (now known as the Permanent Subcommittee on Investigations or PSI), under its new chairman, Joseph McCarthy of Wisconsin, greatly increased the number of investigations and number of witnesses called. His subcommittee held 169 hearings throughout 1953 and 1954. Of the 653 people called by the Committee during a 15-month period, 83 refused to answer questions about espionage and subversion on constitutional grounds and their names were made public. Nine additional witnesses invoked the Fifth Amendment to the United States Constitution in executive session and their