New Release

Dangerous Assumptions

Detective Mike O’Shea is spiralling—consumed by painkiller addiction, alcohol, and the crushing weight of unresolved grief. As his personal demons threaten to take control, he’s pulled into a chilling case: a woman is found dead, her son rotting beside her, discovered only when neighbors are alerted by the unbearable stench of decay.


Meanwhile, O’Shea’s obsession with the killer of his former partner, Sal, continues to haunt him. The elusive murderer has evaded justice for years, but O’Shea has always suspected something more—an untold truth buried beneath the surface. As he digs further, he uncovers a terrifying reality: the killer’s freedom isn’t just a coincidence—it’s the result of high-level corruption that runs far deeper than he ever imagined.
 
As the conspiracy begins to unravel, the threat intensifies, drawing in those closest to O’Shea. Detective Sergeant Amanda Black, one of the few who knows the whole story, becomes the target of an assassination attempt. With her pending promotion and O’Shea’s growing addiction-fuelled paranoia, he starts to wonder if he can still trust her—especially if she’s crossing over.
 
Haunted by years of policing that have left him physically and emotionally scarred, O’Shea is worn down by the weight of it all. Torn between his duty and an overwhelming sense of exhaustion, he struggles to hold on as the stakes rise and the lines between right and wrong blur. He must decide whether to keep fighting—or walk away, knowing the cop killer who took Sal’s life still roams free.

A Word From The Author

“If a real detective wrote crime fiction, what would he write?”

Desmond P. Ryan
Author, Writer, Speaker and Retired Real Detective.

Complete Series

The Mike O'Shea Series

If you love authentic crime fiction, you’ll love The Mike O’Shea Crime Series. In this six-book series, you’ll be absorbed into the world of an inner-city cop trying to do the right thing. Written by a retired Toronto Police Detective, you will find yourself wondering what’s fact and what’s fiction. Be prepared for the emotional rollercoaster that follows as you settle in to read 10-33 Assist PC and Death Before Coffee.

And, when you’re finished, look up Man At The Door, the next book in the series.

A Pint of Trouble Mystery Series - Book Two

Mary-Margaret and The Case of Thieving Barmaid

Bones are found in the lane behind her son’s house. Her best friend and one of the owners of her local become persons of interest for a murder she knows they couldn’t possibly have committed. And the most incompetent homicide investigator on the planet, or so she believes, is the lead investigator. Of course, Mary-Margaret O’Shea, a woman of a certain age with mildly Machiavellian tendencies, has no choice but to get involved.
 
In Mary-Margaret and The Case of The Thieving Barmaid, the second book in A Pint of Trouble Mystery series, unusual alliances, strange coincidences, and more than a few costume-changes lead Mary-Margaret into a world she would have just as soon left unseen.

A Pint of Trouble Mystery Series - Book One

Mary Margaret

When Mary-Margaret O’Shea, a woman of a certain age with mildly Machiavellian tendencies, discovers a homicide scene and meets an unimpressive lead investigator, she realizes that she has no choice but to solve the crime herself. With little help from Michael, her police-detective son, she enlists Arthur, her eccentric housekeeper, to help her find the killer.
 
In Mary-Margaret and The Case of The Lapsed Parishioner, a series of assumptions and misguided steps may lead her to the killer, or they may make her the next victim.
MARY-MARGARET - 2

What Readers Are Saying

“If you love a crime novel that is dark, raw and gritty, then look no further than 10-33 Assist PC.”

5/5
By The Letter Book Reviews

“10-33 Assist PC is gritty, convincing and full of cop humour. “

5/5
Emma-Louise Hamilton

“Ryan delivers what he promises – an authenticity derived from experience.”

5/5
MM Cheryl Book Reviews