Sara Fritz, a Washington-based journalist who worked on early computer-assisted investigations, won awards for her coverage of the White House and Congress, and wrote searchingly about the suicide of her 12-year-old son, died Oct. 16 at George Washington University Hospital. She was 68.

The cause was complications from a lung infection after hip surgery last month, said her husband, James A. Kidney. She was a District resident.

American Journalism Review described Ms. Fritz as one of the “unsung heroes” of political reporting — rarely a schmoozer or schmoozee, never landing on trendy lists of star journalists, and seldom on the receiving end of calculated leaks by powerful people.

But if she was largely unfeted by the Georgetown salon crowd and general public, Ms. Fritz earned a reputation for dogged investigative work that brought her some of the profession’s highest honors. The journalism review likened her to Lt. Columbo, the rumpled but wily homicide detective played on television by Peter Falk.

Her career began inauspiciously in 1966, as a $115-a week copy editor at the Pittsburgh Press. It was a newsroom larded with spittoons, and the few women on staff had to smoke in the bathroom.

Sara Fritz and Ronald Reagan at the White House Correspondents' Association dinner on April 13, 1984. (Harry Naltchayan/The Washington Post)

Her career trajectory and smoking liberties improved after she moved to Washington in the early 1970s to cover the labor beat for the United Press International wire service. She later worked for U.S. News & World Report as White House correspondent during the early years of the first Reagan administration.

As a reporter for the Los Angeles Times for much of the 1980s and 1990s, she covered the Reagan-era arms-for-hostages scandal known as Iran-contra and the Whitewater real estate investigation involving Bill Clinton and Hillary Rodham Clinton.

Richard T. Cooper, a former Los Angeles Times deputy Washington bureau chief, said the Times was one of the first newspapers to invest in a substantial computer-assisted research operation. He called Ms. Fritz a “formidable” spearhead of that effort as it related to her speciality in House and Senate campaign finance.

Reporters could go to the Federal Elections Commission and plumb records about what the oil industry or trade unions, for example, spent on candidates. The Times database, overseen by editor Dwight Morris, was one of the first comprehensive attempts to explore how candidates spent the money they received from political action committees and special-interest groups.

The Fritz-Morris reporting — published in book form as the “Handbook of Campaign Spending” and “Gold-Plated Politics”— looked at hundreds of thousands of separate expenditures for nearly 1,000 House and Senate candidates. They concluded that more than half of the $446 million that candidates spent in the 1990 election cycle was “virtually unrelated to contacting voters,” pointing to elaborate expenses on meals, resort stays, art purchases, unorthodox real estate deals and jobs involving nepotism.

They concluded that the costs of campaigning were far less to blame for systematic abuses that the rivers of easy money that candidates wade in. Their stories raised questions about the value of public financing of congressional races.

“If candidates are squandering campaign funds on personal luxuries or investing the money in political empire building, why should American taxpayers be subsidizing such antidemocratic extravagance?” the authors asked.

In 1989, Ms. Fritz won the Everett McKinley Dirksen Award for the best reporting on Congress for a four-part series — “What’s Wrong With Congress?” — which examined the low regard Americans and many serving on Capitol Hill had for the institution.

Ms. Fritz was part of the team of Times reporters to share the prestigious Polk Award and Goldsmith Prize for investigative reporting in 1997 for their coverage of suspect contributions to the Democratic Party by Asian donors during the 1996 election cycle.

The Times series, “Money from Asia,” also won an award from the Investigative Reporters and Editors organization, provoked congressional hearings into campaign finance reform, and forced the Democratic Party to return nearly $1.2 million in donations, the Times reported.

In a statement Thursday, former Sen. Richard Lugar (R-Ind.) called Ms. Fritz a “probing journalist who exhibited intelligence, integrity and stamina.”

The daughter of an advertising executive, Sara Jane Fritz was born Dec. 16, 1944, in Pittsburgh and raised in Gibsonia, Pa. She was a 1966 graduate of Denison University in Granville, Ohio.

“Those were the days when most women got married right after college,” she told the Denison alumni magazine, “and there were no role models — none — for other careers. . . . I knew I wanted my independence, but I didn’t know what I would do for a career or how I would do it.”

She said she got the job at the Pittsburgh Press because several of the men at the paper were drafted for Vietnam War duty.

Ms. Fritz, a past president of the White House Correspondents’ Association and the Fund for Investigative Journalism, left daily journalism in the mid-2000s after working as Washington bureau chief at the St. Petersburg Times. She held executive jobs with nonprofit organizations, including the Faith & Politics Institute in Washington, and was briefly publisher of the monthly newspaper Youth Today. She had recently completed a book about the legacy of school segregation in Prince Edward County, Va.

Besides her husband of 38 years, of Washington, survivors include a daughter, Mary Kidney of Chicago; and two sisters.

Three years after her son, Daniel, hanged himself in 2000, Ms. Fritz wrote in the St. Petersburg Times about how his depression was “misdiagnosed by his psychologist and a neurologist, who were treating him for attention deficit hyperactivity disorder.”

She wrote of the trauma of his short life and that his suicide would reverberate in the family for generations; she said she contemplated killing herself “several times” after losing him. She found little consolation and catharsis in writing about Daniel.

“Our story proves a truism about parenthood that most of us try to deny,” she wrote. “From the moment our children were born, we did everything we could to keep them physically safe. We bought the best car seats and bicycle helmets.

“We took them to the best physicians. We studied the advice of Dr. Spock and T. Berry Brazelton. We kept close tabs on their whereabouts.

“Now, when we lock the doors of our house at night, we realize how powerless we were to keep them safe,” she added.

“Daniel was not killed by a drunken driver, a faulty product or any other physical hazard that we feared, but by demons inside that we failed to recognize.”