William Bayer [pronounced “byer”] (born February 20, 1939, in Cleveland, Ohio) is an American novelist, the author of twenty-one books including The New York Times best-sellers Switch and Pattern Crimes. Bayer has written a series of novels featuring fictional New York Police Department lieutenant Frank Janek. He has also written adaptions of his novels for television, and written for other TV shows. Switch was the source for seven television movies, including two four-hour mini-series. In all of them the main character, NYPD Detective Frank Janek, was played by the actor Richard Crenna. All seven movies were broadcast nationally by CBS in prime time. Bayer's books have been translated into French, Italian, German, Dutch, Japanese, and nine other languages. He has written two novels under the pseudonym David Hunt, later republished in ebook editions under his own name. He wrote and directed the 1971 feature film Mississippi Summer which won the Best First Feature Award (the "Hugo") at the 1970 Chicago International Film Festival.