I saw that there is a documentary inspired by this book and wanted to read it first before watching. The combination of the horrific details of a string of rapes and murders interspersed with her personal anecdotes about how she came be obsessed with true crime in general and this criminal in particular make for an emotional rollercoaster where you learn as much about the author and other true crime fans (devotees? obsessives?) as you do about the monstrous man she hunted. I'm excited to see the doc now and learn even more, including the effects this book had on the investigation! Spoilers: 

they caught him after this book came out, and I'm interested to see how much impact this book had on that

!