CU on White House - to discuss White House police force, part of treasury agency - secret service. Footage of gate guards screening visitors. CU of two secret service agents scanning mail for threats against president, or cabinet members - CU of mail for President Harry Truman being compared to previous letters for identification of source. Image of Secret Service checking letters for prints. Overhead footage of parade with president Truman - traveling under protection of Secret Service. Several different vantage shots of Truman and his car surrounded by Secret Service. CU of exterior of Bank in city. CU of Secret Service instructing how to catch counterfeit bills. Footage of immigrant men converting foreign money into U.S. money.