He added, “I’d give anything not to have written it.”

Mr. Lardner expanded the story into a book, “The Stalking of Kristin: A Father Investigates the Murder of His Daughter” (1995). Reviewing it in The New York Times, Richard Bernstein wrote:

“A father who has lost his daughter is, it could be argued, not the sort of dispassionate observer to write about that very crime. On the other hand, those who have suffered the kind of terrible loss that Mr. Lardner did are more likely to have the passion and commitment to investigate the issue thoroughly, to track down the operations of the system in every detail.”

George Edmund Lardner Jr. was born on Aug. 10, 1934, in Brooklyn and was raised there and in Jackson Heights, Queens. His mother, Rosetta (Russo) Lardner, was an elementary-school teacher. His father was a syndicated golf writer and part of the celebrated Lardner family of writers; Ring Lardner, the sports columnist and short-story writer, was George Jr.’s great-uncle.

After earning bachelor’s and master’s degrees in journalism from Marquette University in Milwaukee, George began his reporting career at The Worcester Telegram in Massachusetts, then moved on to The Miami Herald. He was hired by The Post in 1962 and developed a reputation there for dogged investigative reporting and elegant writing.

“I was impressed by his complete open-mindedness, skepticism and reluctance to draw conclusions that weren’t warranted,” Mr. Downie , now a professor at the Cronkite School of Journalism at Arizona State University, said. “He had this remarkable curiosity.”

Mr. Lardner investigated the life of Sirhan B. Sirhan after his assassination of Senator Robert F. Kennedy in 1968. He also revealed that Senator Gary Hart of Colorado, then a candidate for the 1984 Democratic nomination for president, had been born a year earlier than he had long claimed, and delved into why he had shortened his surname from Hartpence.

“His biographies give the date as Nov. 28, 1937, but official records in Kansas and a family birth book kept by Uncle George Hartpence reportedly say 1936,” Mr. Lardner wrote.

For many years he followed the threads emanating from President John F. Kennedy’s assassination, from conspiracy theories to investigations. His expertise was clear in a 1991 article critical of the director Oliver Stone for “chasing fiction,” as Mr. Lardner put it, in his film “JFK.”