This book is not a book about Edmund Kemper or Herbert Mullin. Instead they are springboards. Urge to kill is a book about Santa Cruz. It's history and it's title of "murder capital of the world" in 1973. As well as it's place in California and America.
I have read Why: The serial killer in America [Book about the Kemper case] and The die song [Book about Mullin case] and neither of them are even close to Urge to kill's description of 1970's Santa Cruz.
Of all the cases the author gives the most detail in Kemper's case but since the book isnt about Kemper a lot of facts about Kemper are ignored. Such as his childhood and his confession put on audio tape. The author interviewed friends of Kemper who give some great information and comments about the case and Kemper him self.
Ward Damio did an excellent job but does get some facts wrong. Such as when he describes Kemper murdering his grandmother with a shotgun [it was a rifle] while she was typing [she was putting the finishing touches on her children's book.] but the inaccuracies are very few.
An excellent read on the scariest time in Santa Cruz, California's history, when it somehow became the murder capital of the USA. The author does an exceptional job of putting the various crimes into the context of that time and place. He asks how likely it is that the old rule of "what California is, the rest of the country soon will be" is going to apply to mass murder. He comments fearfully on the fact that Ronald Reagan -- openly blamed by a Santa Cruz jury foreman as having a role in the killings -- was, as the book went to press, planning to move on from California governor to become president of the USA. These lines of enquiry make the book, not just thought-provoking, but prophetic. Read this one if you can possibly find a copy.