Last week, word got out that Harper Lee had once written a magazine article about the investigation into the brutal murders of the Clutter family in Kansas in 1959. In researching an updated version of his masterful 2006 Lee biography, author Charles Shields had learned of Lee's unbylined piece which appeared in the March 1960 issue of the Grapevine. That was nearly six years before her friend, Truman Capote, published "In Cold Blood," his masterpiece book about the killings.

This was big news, given that Lee had died in February after publishing only two books herself and refusing all interviews requests over nearly half a century. Typical of the "To Kill a Mockingbird's" pattern, though, it appeared the general public might have to wait to read the article. The Grapevine is a magazine for members of the Society of Former Special Agents of the FBI and its contents usually are restricted to those members.

Well the wait is over. Over the weekend, Grapevine editor Sharon Clasen said they'd decided to let the venerable Smithsonian magazine publish Lee's article on its web site. In a new introduction to the article, Clasen describes how a call from Shields helped them do the detective work to finally track it down in their archives:

“There had been rumors for years that Lee had published a piece in the Grapevine,” Clasen writes, “but her omitted byline kept the story hidden until Shield’s tip revealed the month and year of its publication.”

The article, which contains fascinating details about the Clutter case, is largely a profile of Kansas Bureau of Investigation agent Alvin Dewey, who led the Clutter investigation . And who, not coincidentally, became a star character in “In Cold Blood.”

"It's a little unctuous that piece," Shields told the AJC last week about the Grapevine article which at one point quotes Dewey as vowing to "make a career out of" hunting down the Clutters's killers if that's how long it takes. "It was meant to curry favor with the folks on the ground there, particularly with Alvin Dewey."

Its publication was also meant to fire a warning shot at anyone else even thinking about writing a book about the case.

“They were putting stakes in the ground, making it clear ‘This is our turf,’” Shields told the AJC.

You can read the entire article at Smithsonian.com.

Related: Harper Lee covers "In Cold Blood" case in newly found magazine article