Edward Pierpont Morgan, 72, a Washington attorney and former FBI official who had extensive experience on Capitol Hill, including work with a committee that investigated charges of communist influence in the State Department, died of cardiac arrest March 3 at Georgetown University Hospital. He lived in Bethesda.

Like many Washington attorneys, Mr. Morgan began his career here with the government and even after he entered private practice he occasionally returned to federal service.

He joined the Federal Bureau of Investigation in 1940. His first large assignment on Capitol Hill was as a staff member of the Joint Committee of Congress that investigated the Japanese attack on Pearl Harbor on Dec. 7, 1941, that brought the United States into World War II.

Mr. Morgan rose to be a chief inspector of the FBI and held that rank when he left the agency in 1947 to join what became the law firm of Welch & Morgan. He specialized in corporate, tax and international law, and continued his practice until his death.

In the early 1950s he was chief counsel to the Senate Foreign Relations subcommittee that investigated charges of communist influence in the State Department. The accusations were leveled by Sen. Joseph R. McCarthy, the Wisconsin Republican whose recklessness in this regard made "McCarthyism" a household word.

The chairman of the committee was Sen. Millard E. Tydings (D-Md.), for whom Mr. Morgan worked and with whom he was allied in these proceedings. The Democratic majority concluded that the charges were "a fraud and a hoax." For his role in this, Tydings was defeated for reelection by Republican John Marshall Butler in what has come to be regarded as one of the dirtiest elections in Maryland history.

In 1951, in the midst of the Korean War, Mr. Morgan was appointed chief of the enforcement division of the Office of Price Stabilization.

In 1980 and again in 1985, he was a member of the Presidential Commission on Executive, Legislative and Judicial Salaries. Last year, he was named to the President's Commission on the Bicentennial of the United States Constitution.

Mr. Morgan was born in St. Louis. He graduated from Northwest Missouri University and earned a master's degree in English from the University of Missouri. He earned two law degrees from Georgetown University.

He was a member of the Society of Former Special Agents of the FBI.

Survivors include his wife, Joan, of Bethesda; a daughter, Linda Karam, also of Bethesda; his mother, Pearl Morgan, and a brother, J.P. Morgan, both of Jefferson City, Mo., and one grandchild.