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  Author of the Michael Callaway thrillers 

By Unknown Means         A Fierce Vengeance          Suicide Shot


Thank you for visiting my website. I am happy to announce that my third  book, Suicide Shot is now available on Amazon Books & Barnes and Noble. Suicide Shot is the third book in my Michael Callaway mystery action thriller series that moves our protagonist from his life-long home in Florida to the frozen wilderness of Alaska, where he will do whatever it takes to stop a killer who is out to change the world in a deadly way. 

-Doug Giacobbe 

Doug Giacobbe is a retired law enforcement officer, having served twenty-four years working the mean streets of South Florida. He retired at the rank of Major, and Commander of the Criminal Investigations Division of the Miramar Police Department in 2001. During his service, he was assigned as a patrol officer, narcotics investigator, detective, and internal affairs investigator.

Giacobbe has recently retired as a Professor Emeritus  in History from Daytona State College having taught courses in American, and American Military History. He is the author of By Unknown Means, A Fierce Vengeance, and Suicide Shot  in the Michael Callaway series of thrillers.

He enjoys going on trips with his family (wherever there is something historical to see) as well as golf and fishing. He is a member of Mystery Writers of America, Florida Writers Association and the Phi Alpha Theta National History Honors Society.

“Doug Giacobbe wrote with a fast-paced, smooth cadence that drew me into the story and kept me there. His characters were interesting and well thought out - especially the main characters, both good and bad”—Edie Dykeman, Bella OnLine

“This author is up there with the big guys.”

“The action starts right away and keeps going through a well written and thoroughly researched story.”


Trying to rebuild a shattered life is very difficult and sometimes requires tremendous change. For Michael Callaway it means taking a long boat ride from his usual comfort zone in South Florida and the Bahamas, to the wild wilderness of Alaska. His close circle of friends has withered down to one after the murders of his fiancée, his former partner in the Customs Service, and the Miami District Director of the DEA. His plans to relax and hang out with his last friend ,Navy Commander David Eldridge, go awry from the moment he reaches the Gulf of Alaska. He will get involved with a Russian cargo ship captain who becomes a sinister force in Callaway’s life. He will have to use all his cunning to figure out what the ship captain is up to. Will he have to stop him from firing a Suicide Shot that will ignite World War III?

Suicide Shot

A Fierce Vengeance is the sequel to By Unknown Means, and it will take former U.S. Customs Service Enforcement Agent Michael Callaway into the dark world of revenge. He will learn to break all the rules, and become what he wants to destroy to exact A Fierce Vengeance.

Available on Amazon and Barnes & Noble now,.

A Fierce Vengeance



The first book of the Michael Callaway series

Michael is shocked when he finds his ex-girlfriend Carrie in cahoots with one of the world’s most notorious drug smugglers. Can he take down the mobster and win her back? Or has she been working undercover all along? A pulse-pounding blast.

Praise for By Unknown Means

"A Thrilling Read!"

—Joan Johnston, New York Times bestselling author

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