— J. David Goldin, an eccentric 69-year-old with a handlebar mustache and an obsession with radio, was trolling eBay one evening in September 2010, looking for old radios and recordings, when he spotted an item that piqued his interest: the master copy of a broadcast radio interview with baseball legend Babe Ruth as he hunted for quail and pheasants on a crisp morning in 1937.

For a moment, Goldin contemplated bidding. It was the kind of historic recording that would fit perfectly in his collection of more than 100,000 radio broadcasts, all meticulously enhanced and preserved on tapes stored in thin white boxes on a maze of shelves in his humidity- and temperature-controlled basement “vault.” Then he leaned closer to his computer, adjusted his thick glasses and studied the record’s photograph and description.

What happened next would set in motion a federal investigation with a twist worthy of a classic radio drama.

Goldin exposed what authorities have called “one of the most egregious instances of theft” from the National Archives, where the government preserves billions of historic documents, photographs and recordings. On Thursday, that investigation is scheduled to culminate in the sentencing in Greenbelt’s federal court of a longtime Archives official who has admitted to stealing nearly 1,000 recordings, many of them rare.

In the courtroom will be Goldin, a respected “radio historian” — don’t dare call him a “collector” — who may have been the only person capable of spotting the theft. He lives in a two-story Connecticut house that feels like a shrine to radio: His office is a studio that allows him to preserve and enhance classic records, and the walls are lined with framed albums of vintage radio broadcasts and other bits of nostalgia, including NBC’s chimes and an “On Air” sign. A colorful radio is displayed on nearly every horizontal surface. Among them are a set that doubles as a humidor and another, called a “Mae West,” that has a design feature “you could put a brassiere on,” Goldin said with a laugh.

J. David Goldin’s sharp eye on an eBay listing led to the unraveling of thefts from the National Archives. (Jennifer S. Altman/FOR THE WASHINGTON POST)

“There are some people who give us tips who are just passive. He wasn’t like that,” said the Archives’ inspector general, Paul Brachfeld, whose office investigated the theft and plans to honor Goldin for his help after the sentencing. “He was a sentinel.”

The obsession

The trip to the courtroom for Goldin, who speaks in clipped New York City sentences that often end with a punch line, began the moment he became fixated on collecting old radio shows. The date was Oct. 20, 1955, his 13th birthday, and his mother had just given him a set that included a tape recorder. Soon he was recording classical music and radio dramas in his parents’ Bronx apartment.

By the time he graduated from Stuyvesant High School and New York University, he knew he was destined for a career in his favorite medium. Soon, he was working as a disc jockey and radio engineer at small stations, including one in Sitka, Alaska, where he introduced programs in Tlingit, the language of the area’s native population. As a radio engineer, he edited recordings, spliced tape and calibrated audio machines. “I’m not bragging when I say that I was the best tape editor in the business,” Goldin said.

He eventually joined large networks, including CBS, and became increasingly intrigued by old radio shows, particularly when he stumbled across their announcers or cast members. An announcer of “The Lone Ranger,” for example, turned over a trove of such recordings, which he had stashed in a closet. It was one of Goldin’s most thrilling discoveries, because he was such a fan of the show; with little prompting he enthusiastically recites some of the program’s most famous lines: “From out of the past, come the thundering hoof-beats of the great horse, Silver. The Lone Ranger rides again!”

In his search for radio broadcasts, Goldin was seeking master copies, most of which were made on 16-inch glass or aluminum discs covered in acetate. He enhanced the recordings and transferred them to reel-to-reel tapes, which he used to create vinyl records and audiotapes to sell. By the late 1960s, he was operating a mail-order business called Radio Yesteryear that grew into a large firm, and he even won a Grammy Award in 1981 for producing a record of an old Orson Welles broadcast, “Donovan’s Brain.”

The donation

In the 1970s, as Goldin amassed his massive collection, he decided to donate the master copies to the National Archives. In 1974, he drove to Washington in a rented van and handed several thousand recordings over to an affable and knowledgeable archivist named Leslie Waffen.

The experience was so pleasant that Goldin repeated the trip in 1976. In all, he says he gave the Archives about 10,000 recordings. He and Waffen eventually dropped out of touch.

After selling his business in 1998, Goldin couldn’t stop searching for old recordings and radios, and each evening he scours online auction sites.

On Sept. 27, 2010, he nearly added the Babe Ruth recording to his collection. But after just a few moments, he realized he knew the record well and even remembered parts of the broadcast: “We heard you banging away over in the woods,” an interviewer asks Ruth. “How did you find hunting today?”

“I’ll tell you, just like this, the early bird gets the worm, and I love worms,” Ruth replied.

The recording eventually sold for $34.74, a disappointing sum. “It was Ruth and he certainly should have gotten a lot more than 34 bucks for it — even if Ruth is blowing his nose, people will buy it,” Goldin said.

But what really irked Goldin wasn’t the low price — he didn’t even need to check his computer database to know that he had donated this very recording to the Archives in 1976.

The investigation

At first, Goldin thought the Archives had decided to unload his recordings and that they had found their way to a dealer. He dashed off an irritated letter demanding that the government return anything it planned to sell; it was that missive that launched the criminal probe by the inspector general.

From the seller’s eBay profile, Goldin thought the dealer was a woman (the screen name was “hi-fi_gal”). Hoping to be helpful, Goldin purchased a recording from “hi-fi_gal,” though not one of his donations. When it arrived in the mail, Goldin ran the return address — Saddle Ridge Lane in Rockville — through a reverse directory. It came back to Leslie Waffen, who had retired the previous June as chief of the Archives’ audiovisual holdings.

Goldin was hurt. “To have the chief of the hen house stealing chickens, it is just disappointing,” Goldin said.

Over the next 18 months, Goldin helped authorities build their case, reviewing documents, submitting his original receipts from Waffen and offering up experts to help sort and appraise the cache of 6,153 recordings seized from the retired archivist’s home.

When Waffen, 67, pleaded guilty in October to theft of U.S. government property, he admitted that he stole 955 items from the Archives – among them were original recordings of the 1948 World Series, which Goldin had donated, and a rare recording of the 1937 Hindenburg disaster.

In court filings, prosecutors allege that Waffen stole 2,117 other recordings discovered in his house and that the archivist sold more than 1,000. Waffen faces between 18 and 24 months in prison under federal sentencing guidelines. His attorney declined to comment but in court papers described a dedicated volunteer still struggling with the death of his wife in 1988.

Goldin said he isn’t too upset about what happened — “I don’t get angry,” he repeatedly said in an interview — but he plans on attending Waffen’s sentencing because, like any fan of a classic radio mystery show, he wants to know “how this story ends.”