This was one of the rare books that I could not read close to bedtime. I'm fairly inured to horror and to the stories of other infamous murderers, but Zodiac really gives me the spooks. The story of Zodiac's attack on a young couple at Lake Berryessa is one of the most chilling things I have ever read--the stranger approaches, disappears, reappears wearing a black hood, converses with the youngsters, ties them up, then calmly and coolly says "I'm going to have to stab you people," and then goes about doing just that. I would rather meet up with Ted Bundy or Jack the Ripper than I would Zodiac. I was initially worried about the author's presentation because he included a lot of unimportant details about events occurring before the time of the murders and made comments like the air was "exhilarating" on a particular day--things he couldn't have known and which don't matter at all anyway. However, he quickly settled in to a gripping narrative of events, and his own work on the case was presented fairly well and reveals to us the shifting thoughts and theories he had about the case and the perpetrator who was never caught.
Graysmith tells a good story, but his opinions on the case can be questioned. Also, I have to mention the fact that he was the editorial cartoonist of the San Francisco chronicle at the time and not an investigative journalist. I know this fact should not lead me to discount his conclusions, but it does make me wonder how he came to get as much access to this case as he did. The enigmatic ciphers the killer sent to the newspapers represent unique additions to an already mystifying series of murders, and this book published much of this material for the first time. The longest cipher was eventually cracked by the author; although it was verified by experts as correct, I myself did not feel 100% confident about every detail of the solution. In this and some other matters, the author seemed to make jumps that I could not fully justify; with countless suggestions and theories surrounding this case, it was sometimes difficult to see why Graysmith subscribed to one but not another. When he lists details about other possible Zodiac victims, he leaves the waters pretty murky. His remarks about astrological aspects and the moon perhaps determining the dates of Zodiac's actions are interesting but too vague in description for me to fully consider valid.
I first read this book several years ago, and I have recently seen allusions to the fact that Graysmith named the killer in this book. I did not remember him doing that, so I finally decided to re-read the book now. He does identify a suspect (pseudonymously) whom he believes to most likely be the Zodiac killer, but he has nothing beyond circumstantial evidence with which to "convict" the man. In the years since this book was published, facts have arisen which essentially exonerate this individual of the crimes. Thus, you will not find out who Zodiac was in these pages, but you will find a riveting story about one of the most infamous mass murderers in history. Graysmith's efforts are sincere and to be respected, but they cannot be accepted without a critical eye toward the evidence that has accumulated in the years since this book's publication.