This has long been a rumor but not proved.
Harper Lee was Capote’s “secretary” and traveling companion when he wrote In Cold Blood.
Letter Puts End to Persistent ‘Mockingbird’ Rumor
March 3, 2006 New evidence may end the decades-old speculation that Truman Capote — not Harper Lee — wrote the novel, To Kill a Mockingbird. Dr. Wayne Flynt, retired professor of history from Auburn University discusses the basis for the persistent rumor and explains why it is indeed false.
MELISSA BLOCK, host:
From NPR News, this is ALL THINGS CONSIDERED. I’m Melissa Block.
In the decades since Harper Lee published TO KILL A MOCKINGBIRD in 1960, her novel has been shadowed by a persistent rumor. The speculation has been that Lee’s long time friend Truman Capote either wrote or heavily edited the book, which would go on to be a bestseller and win the Pulitzer Prize.
Well, now a letter from Truman Capote to his aunt, dated July 9, 1959, should help put that rumor to rest. Joining us to talk about it is Wayne Flynt. He is a retired history professor at Auburn University in Auburn, Alabama. And he has researched the writings of both Harper Lee and Truman Capote. Welcome.
Dr. WAYNE FLYNT (Auburn University): Thank you.
BLOCK: Let’s talk first about this letter from Truman Capote. It’s now been made public. It was, as I understand it, given to a museum from a cousin of Mr. Capote. What does it say and how does it help quash this rumor?
Dr. FLYNT: Essentially, it says that a year before the novel was published in July of 1960, that Capote had seen the novel, had read much of the book, and liked it very much, and commented that she has great talent. And nowhere in the letter does he claim any involvement whatsoever in the book.
BLOCK: And by saying that he’s seen it would appear to put some distance at least with it?
Dr. FLYNT: That’s correct. That’s correct.
BLOCK: How did this rumor get started in the first place?
Dr. FLYNT: Well, some claim Pearl Belle, who is a literary critic and editor in Cambridge, Massachusetts, has actually claimed that Capote implied to her that he had written the book or had a good deal to do with the writing of the book. I think probably the rumor results from the fact that TO KILL A MOCKINGBIRD is the only published book that Harper Lee ever did.
BLOCK: Yeah, that that would fuel it. In other words, she was one and done, and if she were such a great writer, why wouldn’t she keep writing great books?
Dr. FLYNT: Exactly. Which basically judges her by the standards of our own culture, which is once you’ve got a taste of fame and fortune, why in the world wouldn’t you continue it?
BLOCK: If you look closely at TO KILL A MOCKINGBIRD and the writing of Truman Capote, do you see anyway that Truman Capote could have written TO KILL A MOCKINGBIRD?
Dr. FLYNT: No. The voice of the characters in TO KILL A MOCKINGBIRD is a totally different literary voice. Some have claimed that he’s so brilliant that he could have simply assumed the voice of his good friend Harper Lee. I don’t believe that for a minute. Writers simply don’t assume another voice, another persona, another kind of literary style......
http://www.npr.org/templates/story/story.php?storyId=5244492
And childhood friend. The part of Dill Harris was based on Capote. The only way Capote would wait 10 years befor claiming to have written the bulk of the book would be if they were very good friends, IMO. Of course, after he bacame a dissolute old drunk, all bets were off... Oh, and as far as I know she's never been on the record denying his authorship.