What Hollywood director wrote a book about an unsolved murder?

King Vidor (pronounced Vee /dor) born in Galveston, Texas in 1901, came to Hollywood in the silent film era. A sometime actor began directing and became one of Hollywood's busiest directors. In the 1960s he began investigating the unsolved murder of director William Desmond Taylor planning to make a documentary on the case. He did discover the murderer but felt it was not the right time to unveil the truth and the whole project was scratched. In the 1980s the book was written by another writer in a book called 'Cast of Killers'. Interesting fact:King Vidor was 2nd director for the MGM movie The Wizard of Oz, filming the famous cyclone scene that takes Dorothy and Toto to Oz.