Books like The informant by Gary May

In 1996, the Aryan Nations was the most dangerous white supremacist group in the United States. This brutally violent neo-Nazi organization dreamed of carving a homeland out of the American Northwest--a dream financed by robbery, intimidation, and murder. The FBI had sought to infiltrate them for years. Enter Dave Hall, a tattooed, 350-pound, six-foot-four former biker. A thoughtful, articulate man with a photographic memory and an unshakeable core of decency, Hall was looking for a new direction in life when FBI agent Tym Burkey found him. But a short-term assignment grew to something much bigger as Hall became the Ohio Aryan Nations leader's right-hand man, and suspected that a significant terrorist action was being planned--but with the ever-present threat of discovery and death hanging over his head, he began to break down psychologically. But it was too late to back out: together, Hall and Burkey would have to finish their dance with the devil.--From publisher description.

FBI agent Jeff Rinek recounts his career tackling high‑profile cases—from the Unabomber to the Jaycee Dugard kidnapping and the Yosemite Park murders—highlighting the pressure of protecting children and stopping serial killers.