'The New York Times'The news, when it came, was short and sweet. Standing on a Florida golf course last week, Gilbert King looked at his phone and saw a two-word text message from an old friend: " Dude . Pulitzer."

King, much to his surprise, had just been declared the winner in the general nonfiction category for "Devil in the Grove: Thurgood Marshall, the Groveland Boys and the Dawn of a New America." The book, about four black men falsely accused of raping Norma Lee Padgett, a 17-year-old white woman in Groveland, Fla., in 1949, unearthed a largely forgotten chapter in the long history of racial injustice in the United States, and explored, in painstaking detail , the tactics used by Thurgood Marshall, the future Supreme Court justice, to chip away at the foundations of Jim Crow law .

Though King did not know it, his publisher, Harper Collins, had nominated the book, which beat Katherine Boo's lavishly praised "Behind the Beautiful Forevers: Life, Death and Hope in a Mumbai Undercity," winner of the National Book Award in the same category in November.

"I'm sure people who write the big, critically acclaimed books know if they're in the running ," Gilbert said during an interview in his small apartment on the Upper East Side, a few blocks from Gracie Mansion. "But I'd just gotten a notice from my publisher that the book had been remaindered8."

King, an amateur historian, stumbled on the Groveland case while writing his first book, "The Execution of Willie Francis," another tale of racial injustice. Groveland "wasn't really covered in a lot of the Marshall biographies, which tend to treat his criminal cases as footnotes," he said. "His clerks knew all about it, though, because he always talked about it when he recalled the old days."

There was a lot to recall, most of it horrific. One of the accused men never made it to a courtroom. He was hunted down and shot to death by a hastily organized posse10. Two others were shot by the local sheriff, Willis McCall, while being transported from state prison to the local jail for a hearing after their convictions were overturned11 by the Supreme Court. One died on the side of the road. The other survived.

King was able to reconstruct events, virtually day by day, after getting his hands on two treasure troves of data. He gained access to the unedited files of the FBI, which sent investigators to Groveland to conduct interviews with local officials and police.

He also persuaded the NAACP to let him see the tightly controlled files of its Legal Defense and Educational Fund. The fund's directors, citing concerns about lawyer-client confidentiality, has been loath to grant access to the material even to eminent civil rights historians like Taylor Branch.

"I don't think anyone had seen those files for 20 years," King said. ''But I just kept at it. I said, 'My focus is very narrow. I just want to look at this one case.'''

King was fortunate in his protagonists. Marshall, already assuming larger-than-life dimensions, was determined to see justice done but focused on cases that let him set legal precedents to dismantle segregation and Jim Crow. The public-relations value of the Groveland case was not lost on him, either.

Every good drama needs a villain. The Groveland case had a memorable one in McCall, a ruthless , brutal man who conducted a one-man reign of terror in Lake County.

"He made Bull Connor look like Barney Fife," King said, referring to the notorious commissioner of public safety in Birmingham, Ala., during the civil rights era. "Connor used dogs and fire hoses. McCall actually killed people."

King traveled a winding professional road on the way to his Pulitzer. A native of Schenectady, N.Y., he attended the University of South Florida with the thought that he might make a baseball career playing second base. That dream died when he got a look at some of the Dominican players the school had recruited.

After coming up two math credits short of a degree in English, he moved to New York and patched together a living doing freelance editing and ghostwriting . One project was a coffee-table book dedicated to antique bicycles.

While working for a publisher of medical magazines, he was asked to fill in and supervise a photo shoot in Puerto Rico. The work appealed to him. He learned to handle a camera, got into fashion photography, and picked up lots of jobs from foreign magazines that needed a man on the spot in New York.

His two books enjoyed only modest sales, and he is undecided what the next project might be. When the Pulitzer news came, "I was sort of lying low," he said. Three times a month he writes offbeat historical stories for Past Imperfect, a blog on Smithsonian magazine's website. His topics have included the great Australian prison break of 1876 and, to coincide with the Masters tournament, the story of Craig Wood, the unluckiest golfer of all time.

It was while editing a crime encyclopedia that he found the subject of his first book. Willie Francis, a teenager convicted of murdering a white pharmacist in St. Martinville, La., in 1944 and sentenced to die in the electric chair. Because of a malfunction, Francis survived electrocution; a local lawyer, arguing that a second electrocution would be cruel and unusual punishment, took his case all the way to the Supreme Court.

King, a fan of Walter Mosley's historical crime novels, took full advantage of the setting , in the heart of Acadiana, to spin an atmospheric yarn around the facts. "It became a strange Cajun murder mystery," he said.

It ended badly. In 1947, weary of the legal battles being fought on his behalf, Willie Francis took his seat once again in the chair nicknamed Gruesome Gertie. There were no glitches the second time around.

In the case of the Groveland Four, King was able to track down some participants; the case still burns in local memory. When he returned to Groveland for a reading, the local librarian informed him that two threats had been phoned in. "Don't worry," she said, "we called the sheriff's office." King savored the moment.

One interview subject he saved for last: Norma Lee Padgett herself, who lived in a trailer at the end of a dirt road in rural Georgia. A relative answered the door of a second trailer on the property and acted as a go-between . The message he brought back to King was, "Let sleeping dogs lie."