Cliff Knowles Mysteries


Fatal Dose by Russell Atkinson

Book #3 in the Cliff Knowles series

X-rays can kill cancer cells and save lives when administered properly. They can also kill people when things go wrong – a fact learned the hard way by retired FBI agent Cliff Knowles. Hired to unravel the cause of some mysterious overdoses, he gets too close to the truth and finds his own life on the line.

Inspired by actual cases he worked as an FBI agent in Silicon Valley, the author weaves an absorbing tale of greed, technology, and terrorism in this high-tech legal thriller. After reading Fatal Dose you’ll never look at an X-ray machine the same way.

Fatal Dose follows geocaching FBI agent Cliff Knowles in the third riveting installment of the popular Cliff Knowles Mysteries series.

Kindle ebook from $4.95

Trade paperback (sold in U.S. only) $13.00 (Calif. residents add 8.75% sales tax)
FREE SHIPPING! May be available from Amazon elsewhere.


Cached Out by Russell Atkinson

Book #2 in the Cliff Knowles series

Newly retired from the FBI and alone after the tragic death of his wife, Cliff Knowles takes up geocaching. While looking for a cache in the mountains he comes across a human skeleton and reports it to the sheriff's office. Then a second body is found - a fresh corpse this time - right after Cliff found another geocache nearby. When it turns out the first remains are those of a fugitive he was supposed to arrest years earlier, he becomes a suspect in a multiple homicide investigation. He has no choice but to use his sleuthing skills to identify the mysterious cache owner, known only as Enigmal, and free himself from suspicion.

Kindle ebook from $4.95

Trade paperback (Sold in U.S. only) $13.00 (Calif. residents add 8.75% sales tax)
May be available in foreign countries from Amazon.



Held for Ransom by Russell Atkinson

Book #1 in the Cliff Knowles series

The President of Claritiva Software is kidnapped at gunpoint. FBI Special Agent Cliff Knowles is the first to respond when the crime is reported. But the report is suspicious in many ways and the front office is skeptical the kidnapping is real. Knowles must fight his own bureaucracy while trying to rescue the victim and catch the kidnappers. This gripping novel will have you on the edge of your chair from the first chapter.

The author, a retired 25-year FBI veteran Special Agent, draws heavily on his experiences working high-technology and violent crimes cases in Silicon Valley to provide an unprecedentedly candid look at what it is like to work a high-profile kidnap case and what a kidnapping victim experiences. If you have considered becoming an FBI agent, or you have wondered what you would face as a kidnap victim and the decisions you would have to make, this book is a must-read. This is the real story, not the TV version you've seen a thousand times. It isn't always pretty, but it is what happens when lives are at stake.

Kindle ebook $3.95

Soft cover on sale at Amazon

About the Author

Russell Atkinson served as an FBI Special Agent for 25 years, where he specialized in high-technology crimes in Silicon Valley. He was the case agent on the first federal prosecution in California under the Economic Espionage Act. He was the first to investigate Raj Rajaratnam, the high-tech hedge fund manager who was convicted of massive insider trading in 2011. He worked on the Polly Klaas kidnapping case and has arrested murderers and drug dealers. After retiring from the FBI he became a full-time litigating attorney. With degrees in mathematics and law he worked for many high-tech firms in the computer industry including IBM, Fairchild Semiconductor, and Netscape. He served as President of the American Cryptogram Association and has written extensively on cryptographic topics. He was Head Cryptographer for the movie The Red Machine, which was given a thumbs up by Roger Ebert. Now retired, he lives with his wife in Silicon Valley and spends time with his interests: running, geocaching, guitar, cryptography, and, of course, writing.

He can be contacted at

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