In October 1948 Pauling stood with four other Caltech faculty members at a special school ceremony where they were awarded Presidential Medals for Merit, the highest civilian award given by the government. Pauling won the award for his wartime research into explosives, rocket propellants, and artificial blood (during the War Pauling had also invented an air-testing device for submarines and patented an armor-piercing shell). The citation on his award, signed by Harry Truman, noted Pauling’s "imaginative mind," "brilliant success," and "exceptionally meritorious conduct in the performance of outstanding service to the United States." As he received this distinction, the FBI’s investigation of his life, his associates, his family, and his work continued.