Perilous Obsession

Brad Parker and Karen Richmond Book 5

Finalist for Maine Literary Award in Crime Fiction

A tragic overdose, an institutional coverup, and human trafficking. When Dr. Brad Parker helps investigate the death of a patient at a Portland, Maine cancer center, he senses a coverup to protect the responsible physician. His suspicions are quickly confirmed when both doctors involved in the case are found dead. As Brad and his partner—FBI agent Karen Richmond—investigate, they uncover a hospital-based sex trafficking operation. Leaving them struggling to identify the man at the top before the victim count rises.

Where to Buy Perilous Obsession


Maine Authors Publishing

Audio book now available on Amazon or Audible

Praise for Perilous Obsession

Perilous Obsession is Ogunquit author Geoffrey Cooper’s fifth mystery in his thriller series featuring Brad Parker and FBI Special Agent Karen Richmond. And this is probably the best one of all. Parker knows the medical game and Richmond knows how to squeeze witnesses and suspects to get information. She is much more devious and lethal–they are a perfect team.” Bill Bushnell, Central Maine Sentinel

“In this fifth installment of an ongoing series, Cooper deftly uncoils a complex scheme that not only involves murder, but also human trafficking. Despite its complications, the plot advances at a brisk pace, and the book is brimming with cinematic action and intrigue. An often exciting tale of medical malfeasance and wide-ranging criminality.” Kirkus Reviews

Perilous Obsession: A Medical Thriller is especially recommended for readers of Robin Cook and his ilk, who will find Geoffrey M. Cooper’s story a riveting tale. He is particularly skilled at creating the kinds of twists and turns that lead readers up one area of possibility before taking a quick turn in the opposite direction. Cemented by Brad and Karen’s relationship and investigative skills and their connections to the medical world, Perilous Obsession is a thoroughly absorbing drama highly recommended for any fan of medical thrillers.” D. Donovan, Midwest Book Review

“Dr. Brad Parker and FBI agent Karen Richmond are at it again in another fast-paced medical thriller. With a double homicide to solve, Parker and Richmond find their own lives in danger as they work to unfold who is behind a possible sex trafficking group. Perilous Obsession will have its readers finishing it in one sitting. Action-packed with surprises at every turn.” Manhattan Book Review

“The fifth book in the Professor Brad Parker and Karen Richmond series, Perilous Obsession is a gripping medical mystery. With his scientific background, Geoffrey M. Cooper writes with authority and authenticity blending thrilling action with medical intrigue. Though the novel works as a stand-alone entry point to the series, those who have followed Parker and Richmond from the very beginning may get the most from the book and will particularly enjoy the way their relationship has evolved by the close.” IndieReader

“The characters are witty and the storyline is packed with twists and turns. This is a page-turner that will have you sitting on the edge of your seat right to the end.” San Francisco Book Review