Frank C. Conahan, 72, who testified more than 150 times before congressional committees, identifying waste, fraud and ill-conceived federal initiatives, died of liver failure Sept. 28 at his home in Bowie.

Mr. Conahan, as assistant comptroller general at the General Accounting Office during the 1980s and 1990s, was a familiar face on Capitol Hill, spotting the costly future of the Strategic Defense Initiative, also known as Star Wars. He also reported on failed government attempts to stop the cocaine trade and uncovered federally funded radiological, chemical and biological experiments on humans.

He had no fear of standing up to generals, senators or Cabinet secretaries, his family and colleagues said, but managed to retain their respect even while publicly demonstrating their conclusions as faulty.

Responding to a general who called the B-1 bomber the best warplane in the world, Mr. Conahan said, "It might be the best plane ever made -- except it can't do its mission."

"There is today a lack of candor on the part of the Air Force with respect to these [financial] problems," he said in 1987 before a subcommittee of the House Armed Services Committee. "The solutions can be forthcoming only when the Air Force becomes more forthcoming."

He was just as hard on the other branches of service, reporting in 1984 that nearly one-fourth of the Navy's heat-seeking Sidewinders and one-third of its radar-guided Sparrows were "unserviceable" and not available for combat. Eighty percent of the Marine Corps' radio-steered TOW antitank missiles had "safety problems," including rocket motors that tended to misfire, and so could be used only in "emergency situations," he added.

In 1992, the Council for Excellence in Government said Mr. Conahan held one of the 60 toughest science and technology jobs in Washington. Work performed under his oversight, roughly 4,000 audits or reports, resulted in more than $100 billion in savings for the federal government.

The National Academy of Public Administration's public service award in 1991 called him "the person most responsible for establishing GAO as a recognized and influential authority on defense and international affairs issues," a notion that his successor, Butch Hinton, seconded.

"He invested himself in the issues. He learned and became an expert on the subjects," Hinton said.

Mr. Conahan spent his entire federal career at the GAO, working his way up to near the top of the agency.

He was born in Wilkes-Barre, Pa., and graduated from King's College in his home town. He later did postgraduate work at the University of Michigan and Harvard University.

He joined the GAO in 1955, then served two years of active duty in the Navy before returning to the GAO. He was a regular lecturer at the Brookings Institution, the Defense Systems Management College, the National Security Agency and American University, as well as other universities.

After retiring in 1995, he was senior fellow at the Logistics Management Institute in Fairfax and an adjunct faculty member at Prince George's College. He was a member of Sacred Heart Catholic Church in Bowie.

Mr. Conahan also was a familiar face at the District's annual St. Patrick's Day parade since its beginning in 1971 and often was seated on a green chair beneath a banner bearing his family's name and crest.

"We brought our kids, and now we're bringing the grandchildren," Mr. Conahan said in 1998. "We like the atmosphere -- and the fact that we always go to a pub afterward is part of it, too."

His wife, Anne M. Corrigan Conahan, died in 2002.

Survivors include four children, Frank Conahan of Waldorf, Tom Conahan of Sykesville, Nancy Coon of Columbia and Marguerite West of Manchester, Md.; and 10 grandchildren.

Frank C. Conahan often testified on weapon systems' shortcomings.