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Breaking through to the truth is deadly.

After months of nerve-wracking undercover work, Detective Erin O’Reilly is finally getting ready to bring down the Irish Mob. She has everything she needs: recordings, witnesses, and even the secret O’Malley ledger. She just needs to wait a few more weeks while the NYPD makes the final preparations to drop the hammer. If everything stays calm on the street, there’s nothing to fear.

But a routine construction job in Brooklyn shatters Erin’s hopes for peace. When a work crew unearths a trio of decade-old bodies, a cold homicide case heats up fast. One of the dead men is a missing O’Malley associate linked to a long-ago turf war with crooked Teamsters.

Erin and the Major Crimes squad start digging to find the truth, but unhinged gangster Kyle Finnegan wants answers too. Finnegan may be crazy, but he’s also smart. He’s more than willing to break anything and anyone to reach his goal. Erin and Rolf will have to smash through enemies and so-called allies alike to unearth a secret worth killing for.

344 pages, Kindle Edition

Published December 11, 2023

92 people are currently reading
20 people want to read

About the author

Steven Henry

37 books81 followers
Steven Henry is the USA Today bestselling author of the Erin O’Reilly mysteries and the Clarion Chronicles.

Steven learned how to read almost before he learned how to walk. Ever since he began reading stories, he wanted to put his own on the page. He lives a very quiet and ordinary life in Minnesota with his wife and dog.

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5 stars
160 (75%)
4 stars
41 (19%)
3 stars
10 (4%)
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Displaying 1 - 10 of 10 reviews
290 reviews3 followers
December 13, 2023
W O W!! Great read!!

Jackhammer has got to be one of the most complex of the Erin O’Reilly stories!! There were numerous peaks - one after another! Kyle Finnegan was a heckuva character!!! But all the way thru, that was unexpected, then that was unexpected, and so on. I could not have guessed WHO dunit at any point!!!

Then the Vic & Zofia story was great too!!

Love the series, but this was definitely a fave.
15 reviews1 follower
December 20, 2023
Learned a new word for being thrown out a window.

Finally getting a better understanding of Finnegan.
961 reviews4 followers
January 4, 2024
One of My Favorite Series!

Before you read this book, read "Angel Face" (Book 18), then Tequila Sunrise: The James Corcoran Story, and then Books 19-21. This is not a standalone book. If you haven't read ANY of this series, read them all in chronological order from Book 1 to book 21, including ALL of the individual stories in between of Ian Thompson and Lt. Webb. You can get complimentary copes of the side stories when they are offered in the numbered books.

"Jackhammer" is Book 22 of The Erin O'Reilly K-9 Mystery series, written by Steven Henry. This episode is about the continued undercover operation going on between Erin O'Reilly, Philip Stachowski, and a few other players, to bring down the O'Malley Crime Family in New York City. New York City has five burroughs, but this episode is mainly Brooklyn and Manhattan, where Erin and other key members of New York's Finest, plus criminals, and reformed criminals, all go back and forth, in order to either protect a bad guy or bring down that bad guy. The bad guy in question is one of O'Malley's men, Kyle Finnegan, a really crazy and insane guy who was hit in the head with a tire iron 10 years earlier, and goes around quoting Shakespeare plays, as well as other works of literature. He seems to be after the people who murdered a friend of his, and then that person, along with two other men, were buried alive in cement 10 years earlier. There are many bad guys: the O'Malleys, the Teamsters from three different trucking companies, and even some dirty cops. Many people get hurt by Finnegan, one of them being a little boy who is only about 3 or 4 years old, and a family dog is killed. Erin has to find this guy, as well as the other bad guys who murdered three men and buried three men alive all those years ago, while still protecting her undercover identity. As with all of this series, my favorite character is Rolf, the German Shepherd K-9 on the front of Book 1 of the series. Steven Henry has given Rolf a personality of his own that readers can't help but love. I gave this book 5 stars, and when book 23 is available, it will be added to my Kindle Library.
9 reviews2 followers
January 28, 2024
Another great book in this series

Love this series. It gets better and better. The police work is well described, the NY info is woven in well, and I even love the sections written from Rolf's point of view. Excited for the next book.
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916 reviews6 followers
February 20, 2024
Vic bonus story

It was an absolute delight and a nice topping to the original Erin story which, by the way, is certainly heating up. I do hope Lt. Phil is going to be okay at the end of Book 23!
16 reviews
December 23, 2023
fun read

Love Vic and Zofia. Great couple. Nice to let them have their own adventure! Hope for more to read in the future.
5 reviews
March 4, 2024
I Couldn’t Put it Down

I could not put Jackhammer down any more than I could any of the other
21 books of Steven Henry. Bring more on!
Profile Image for Megan.
18 reviews
April 11, 2025
love the extra

Great story in Jackhammer. Cringed with some of the descriptions. Fun extra short story about Vic and Zofia. Nice bonus
7 reviews
January 8, 2024
Good read!

It followed in the same context as the Erin O’Reilly Mysteries. Good side story only without Erin being directly involved.
Profile Image for Jo Anne.
955 reviews10 followers
January 5, 2025
I'm really enjoying reading about the secondary characters featured in the books. The last book gave readers more time with Judge Ferris and now in Jackhammer, it's all about the dangerous and crazy Kyle Finnegan. Long time readers know Finnegan's head was caved in by a tire iron wielded by a Teamster. Badly wounded, he still managed to kill the three men who attacked him.
Strange before his head was bashed in, Finnegan is now crazy like a fox or totally insane. Remember having to read Hamlet in school and then writing the "is Hamlet crazy or faking" paper? Even after finishing Jackhammer, I still couldn't say if Finnegan was crazy or faking. He quotes Shakespear and twists his words into pretty sentences. Erin is afraid of, and annoyed with, him and she herself can't figure him out.
Three men have been found buried in a pit in a parking lot; the pit was filled with cement
Displaying 1 - 10 of 10 reviews

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