[3] Donahue first became interested in the story of the assassination of John F. Kennedy after participating in a re-creation of the shooting as one of eleven invited marksmen and sharpshooters.

However, the experience highlighted to Donahue other concerns regarding the Warren report — in particular, the fact that the testimony of ballistics experts seemed to have been completely omitted from the Commission's evidence gathering.

[4] Conducting his own investigation, Donahue eventually decided that the bullet that struck Kennedy in the head had in fact been fired by United States Secret Service Special Agent George Warren Hickey Jr. (March 24, 1923 – February 25, 2005) from an AR-15 rifle carried in the car immediately following the President's vehicle.

The proposed series of events is as follows: After the first shot (which hit the street) was fired, Hickey turns completely around and looks toward Oswald, who is on the sixth floor of the school book depository building.

Hickey, who is unstable because he is standing on the cushion of the seat, rather than the floor of the car, begins to fall back due to the acceleration of the vehicle, pulling the trigger of the AR-15.

The Acknowledgements section (dated January 21, 1992) begins "Special thanks to Nick Beltrante for a great news tip, the late Ralph Reppert for showing the way, Howard and Katie Donahue for casting their lot with me ...".

Chapter 1, A Chance Telephone Call, describes the events that led to Donahue's interest in the assassination, and a brief biography up until that point.

(p. 56)Chapter 6, A Fortuitous Encounter, describes Donahue's first correspondence with the Secret Service, and reviews the conclusions that led to his approaching them.

In just eight months, working on weekends and evenings in his cluttered basement den, he had been able to construct a rebuttal to the critics of the Commission's single bullet theory that effectively destroyed their principal arguments.

Chapter 8, Murphy's Law, resumes the story of Donahue's career as his expertise and reputation as an expert witness grow.

(p. 108)Chapter 10, Breaking News, describes the first publication of Donahue's conclusions in articles by Ralph Reppert, and attempts to contact Hickey.

Rose, ... an investigator for the committee, ... informed Donahue that he'd traveled extensively around the country to question a number of Secret Service agents and police officers about what happened in Dallas.

Our own rifles ... (p. 196)Chapter 15, The Final Breakthrough, presents more ballistics, especially estimating the size of the head shot entry wound and its relevance.

(p. 199)Chapter 16, Hope Dies Hard, gives a brief history of the Secret Service, their nightmare assignment guarding Kennedy, and their reaction to the shooting.

Chapter 17, Today, is a recap as of spring 1991, describing reactions from Secret Service agents and others to the theory, and more attempts to contact Hickey.

[15] Balducki praised the book, saying, "Menninger interprets the story with a sharpness and fluidity that never unravels amid the surge of detail.

[19][20] In 2013, Australian journalist and former police detective Colin McLaren published a book and documentary both titled JFK: The Smoking Gun, examining and supporting Donahue's theory.

"He had discovered a TV tape in a German archive that showed the assassination from a different angle as well as a Secret Service agent standing up in a car."

[22][23] The suit was eventually dismissed in 1997 on the grounds that Hickey had waited too long after the book's initial publication to file against the publisher.