Joseph L. Nellis, 87, a lawyer who served as general counsel to a congressional committee that investigated organized crime and another that investigated drug abuse and control, died July 10 of congestive heart failure at his home in the District.

Mr. Nellis spent most of his career on Capitol Hill, both in and out of government, and was a longtime Democratic Party adviser.

His father ran Chicago's Ambassador Hotel and was well-connected politically. One of his father's friends, Sen. Estes Kefauver (D-Tenn.), called Mr. Nellis in late 1949 with a proposition for the young lawyer, then in private practice in Washington.

"Joe, I'm about to get the Senate to pass a resolution authorizing an investigation of organized crime," Mr. Nellis had recalled the senator saying. "It's never been done before. Why don't you come up to the Hill and help me chase some gamblers?"

Mr. Nellis signed on as associate counsel and became one of the youngest members of a Senate investigation into the activities of organized crime in interstate commerce.

During the committee's televised hearings in New York in 1950 and 1951, Mr. Nellis questioned organized crime figures such as Frank Costello and Virginia Hill. The hearings helped raise Kefauver's profile in his quest for the Democratic presidential nomination in 1952 and 1956. In 1956, he was the party's vice presidential nominee.

A few years ago, Mr. Nellis recalled deposing entertainer Frank Sinatra regarding his connection to then-exiled crime boss Lucky Luciano. Mr. Nellis, who agreed to conduct the deposition at 2 a.m. to avoid the media, determined that calling Sinatra as a public witness would be of no benefit to the committee and might damage Sinatra. He had surveillance photos of Sinatra with his arm around Luciano on the balcony of the Hotel Nacional in Havana.

"He put it off by saying these were his friends, these were people he'd met, that his mother knew and made no apologies. But I could see the fright in his eyes," Mr. Nellis told an interviewer in 2000.

"He had one explanation for it all: When I was first starting out, these people gave me a break," Mr. Nellis said. "He said if he could not get a job he could always turn to one of his friends. He knew they were mobbed up, but they paid him a salary."

Mr. Nellis later served as chief counsel of the House Select Committee on Narcotics Abuse and Control. In 1977, he was dispatched to Southeast Asia's "Golden Triangle" -- Burma, Laos and Thailand -- a haven for the producers of heroin poppies.

He ventured into the northern Burma fortress of Khun Sa, often called the opium and heroin warlord of Southeast Asia. Mr. Nellis secured Sa's agreement for what Mr. Nellis described as "a preemptive purchase of his entire opium crop for $36 million through the United Nations drug agency."

The agreement also called for a thorough inspection to prevent cheating and a crop-substitution program for the peasants who grew poppies.

"The Carter administration gave various excuses for refusing to consider or finance the deal, but if the United States had had the guts to try such an innovative approach, we would have removed from the U.S. market up to 100 tons of heroin," Mr. Nellis wrote in a 1989 Washington Post letter to the editor.

Mr. Nellis was born in Minsk, in what is now Belarus, and grew up in Chicago. He graduated from the University of Wisconsin and Northwestern University Law School. Before World War II, he worked at the Office of Price Administration, where he dealt with black market activities.

During World War II, he did cryptology work while serving in the Army Air Forces. In the late 1940s, he worked for the U.N. Relief and Rehabilitation Administration, helping post-war relief efforts in Greece and Italy.

After returning to Washington, he argued several major civil and corporate cases, including the U.S. Supreme Court's first decision on the constitutionality of antiabortion laws (United States v. Vuitch, 1971). He also played a role in the successful argument of Roe v. Wade by assisting the lawyers as they prepared for their appearance before the high court.

Mr. Nellis wrote articles in professional and general-interest publications and was the co-author of "The Private Lives of Public Enemies" (1973).

He also was an adviser to presidential candidates, including Kefauver and former Illinois governor Adlai Stevenson, and in 1968, he served as deputy director of Citizens for Humphrey-Muskie. A friend and adviser to former first lady Eleanor Roosevelt, he served as general counsel for the Eleanor Roosevelt Foundation.

As a businessman, Mr. Nellis developed downtown properties and was a founder of the GEM (Government Employees Mart) Department Stores.

Mr. Nellis's marriage to Vivian Wiener Nellis ended in divorce.

Survivors include his wife of 40 years, Muriel Nellis of Washington; two children from his first marriage, David Nellis of Kensington and Barbara Nellis of Chicago; two stepchildren, Adam Pressman of Washington and Amy Pressman of Pasadena, Calif.; and nine grandchildren.

Joseph Nellis helped investigate organized crime and drug abuse.