"People always say, 'Where do you get (your characters') words?' And I say, 'Can't you remember people talking or think up people talking in your head?' That's all it is. I don't know why that seems such a wonder to people," he told The Associated Press last year.
Leonard spent much of his childhood in Detroit and set many of his novels in the city. Others were set in Miami near his North Palm Beach, Fla., vacation home.
He died at his home in the Detroit suburb of Bloomfield Township, where he did much of his writing, from complications of a stroke he suffered a few weeks ago, according to his researcher, Gregg Sutter. The writer was surrounded by family.
One remarkable thing about Leonard's talent is how long it took the world to notice. He didn't have a best-seller until he was 60, and few critics took him seriously before the 1990s.
Now, the Library of America, which publishes hardcover editions of classic American writing, is planning a three-volume set of his work.
He had some minor successes in the 1950s and '60s in writing Western stories and novels, a couple of which were made into movies. But when interest in the Western dried up, he turned to writing scripts for educational and industrial films while trying his hand at another genre: crime novels.
The first, "The Big Bounce," was rejected 84 times before it was published as a paperback in 1969. Hollywood came calling again, paying $50,000 for the rights and turning it into a movie starring Ryan O'Neal, that even Leonard called "terrible."
He followed up with several more well-written, fast-paced crime novels, including "Swag" (1976). Leonard was already following the advice he would later give to young writers: "Try to leave out the parts that people skip."