The word is murder

Detective Daniel Hawthorne needs cash. Having gotten himself fired from the police, Hawthorne decides to approach Anthony Horowitz. Hes investigating a complex murder and he wants Anthony to write a book about it, a bestselling book of course, with a 50/50 split. The only catch is they need to solve the crime. A classic crime for the modern reader, this is a whodunnit to end all whodunnits.