Long before literary provocateur John D’Agata was rankling the journalistic establishment with his unorthodox reporting “techniques” — changing dates, merging quotations, altering statistics, constructing composite characters — to “seek a truth … but not necessarily accuracy,” writer Truman Capote was doing the same in his most famous work, 1966′s In Cold Blood.

Capote always insisted his “non-fiction novel,” his new literary form, was “immaculately factual.” But almost immediately after the book was published by Random House after being serialized in the New Yorker, he was accused of getting the story wrong by Esquire magazine writer Philip K. Tompkins in a June 1966 piece titled “In Cold Fact.”

Over the years, the accusations have continued from many corners, including friendly ones. In his sympathetic 1988 book, Capote: A Biography, Gerald Clarke acknowledges that the final scene in the book, which takes place at a graveyard, is fiction. That scene, which is filled with dialogue, has the investigator in the murder case meeting with a friend of one of the slain girls in the cemetery where the murdered Clutter family is buried. Clarke writes that Capote constructed it: “Since events had not provided him with a happy scene, he was forced to make one up.”

A new book by Ralph L. Voss, Truman Capote and the Legacy of In Cold Blood, draws on previous literary forensics and his own scholarship to demonstrate Capote’s shocking faithlessness to the truth. Capote disputed his critics’ claims that he had dropped fiction into his non-fiction, telling one interviewer in 1972 that Esquire was wrong, reiterating: “What I wrote in the book was true.” Even though Voss spends only a couple of chapters debunking In Cold Blood (most of it is a celebration of the book and its influence), he makes it impossible for readers to deny that Capote cut corners, sweetened his material, wrote passages that argue with the facts in his notes and invented scenes.

What separates D’Agata, author of About a Mountain and a new controversial book, The Lifespan of a Fact, from Capote, of course, is his candor in interviews about his manipulations. In D’Agata’s mind, the sort of fact-bending he indulges in is no different from the mixing of hues committed by a painter at his canvas. D’Agata calls himself an “essayist,” not a journalist or a non-fiction writer, which he says gives him greater liberty at the keyboard. Capote, on the other hand, always insisted that his non-fiction was near to photorealistic, relying on no darkroom tricks to find artistic truth.