American Ripper is the true story of Gerard John Schaefer, a Florida law enforcement officer who was a prolific serial killer in the late 1960s early 1970s. The decade that was thought to be filled with love, peace, and happiness became a new dark age, breeding more serial killers than any other time in US history including Charles Manson, the Zodiac Killer, the Son of Sam, John Wayne Gacy, and Ted Bundy, who was held in the same prison as Schaefer and whom he both idolized and resented for the recognition his crimes brought him, a recognition Schaefer never received.

This book chronicles Schaefer's life, education, his career as a cop, and his path to become a sadistic murderer. Based on extensive empirical research that includes reviews of the case's investigation and subsequent trial, interviews with families of victims, numerous police and attorneys involved with the case, forensic doctors, and the killer himself, the author attempts to discern how Schaefer became the antithesis of what a lawman should be. Schaefer's metamorphosis can never be rationally explained, but reviews of the case's transcripts, the killer's psychiatric evaluations, and the author's own experience with Schaefer help paint a picture of an unfettered mind that fed on its own darkness.