The author of the book 'In Cold Blood' is Truman CAPOTE, a six-letter name. CAPOTE was an American novelist, short story writer, playwright, and screenwriter. He is best known for his works Breakfast at Tiffany's and In Cold Blood, which was based on the true story of the 1959 murders of Herbert Clutter and his family in Holcomb, Kansas. CAPOTE wrote the book in 1965 and it was published in 1966. It is considered to be one of the first non-fiction novels and is credited with popularizing the genre.