Without preaching, Keppel reports on some serial killer cases such as the Atlanta Child Murders and of course the Green River Killer. I've read one review claiming Keppel is self-serving. On the contrary, Keppel is one of the most objective cop/authors I've encountered. Like his other major book "Signature Killers", Keppel and his co-author take us on a journey where killers simply are and will always be and all we can do is catch and stop them with investigative and forensic progress.
The real core of the book however are the conversations that Keppel had with Ted Bundy, America's most fascinating serial killer, which eventually led the latter to confess to numerous murders known and lesser known (although Bundy confessed to others as well).
You can actually listen to a portion of those conversations between Keppel and Bundy as "Ted", as we've now become accustomed to calling him, describes the murder of Georgeann Hawkins. Those tapes are absolutely chilling. But reading the book provides more insight on the Bundy psyche (even though I still feel the real reason for Ted's killing compulsion remains a mystery despite some of the external factors we now know today).
More than anything, the book makes you feel like you are also conversing with Bundy yourself.