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"The accuracy of medical details and credible bomb threats mixed with genuine characters guarantees an unputdownable read. Buckle in and get ready for a fast-paced ride!" –Ivanka Fear, author of The Dead Lie and Where is My Husband?

Las Vegas, the entertainment capital of the world, hosts an F1 race, the largest sporting event in the city's history and a prime target for terrorism. With over a half million people descending on the Strip for the event, a bomb detonated in a parking garage days before the race. In the emergency room, Doc fights to save the lives of a pregnant doctor and her premature baby injured in the blast, spurring him to risk his own life to find justice for the victims. He is joined by his girlfriend Lana, a smart, ambitious reporter, his friend and colleague, Rick, and his trained ex-police dog Banshee. Their investigation takes them from a seedy bar to iconic landmarks around Las Vegas and crescendos on the night of the race when chaos reigns in the city. As the sun rises, they reveal a deceptive scheme to close the case. An action-packed thriller, Sin City Treachery entertains with a story that leaves readers guessing until the end.

279 pages, Kindle Edition

Published June 13, 2024

2118 people are currently reading
836 people want to read

About the author

Gary Gerlacher

17 books373 followers

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5 stars
5,371 (65%)
4 stars
2,241 (27%)
3 stars
541 (6%)
2 stars
56 (<1%)
1 star
23 (<1%)
Displaying 1 - 30 of 303 reviews
Profile Image for Teju  A.
417 reviews34 followers
November 18, 2025
Aj's and Banshee are back, this time on the heels of a bomber. As the noose tightens on the culprit though, It just might be a smokescreen to a bigger plan with a heavy payday. This was a good mystery!!!!

Solid 4.5 stars!!!
Profile Image for Merry .
879 reviews294 followers
November 23, 2025
The 3rd in the series that I have read in order. I enjoy Gerlachers writing and his characters Doc and Banshee. The added character of his girlfriend, Lana, added to the flow of the plot. The red herrings were good, I did suspect the bad guy, but WOW did this have a lot of twists. Could any of this really happen I doubt it. I did find the storyline a little too far-fetched at times and that is why it gets a 4* instead of 5*. Looking forward to reading the next book.
31 reviews
June 16, 2024
I enjoyed book 1 and 2 of the series. Very well crafted, developed and resolved. The main characters: Banshee and AJ (Doc) could not be better. They showed the author took his time thinking about the plot and characters.
I was therefore looking forward to book 3, but I must say, it was a disappointment. If, for whatever reason, the author felt compelled to include a woman as the main character, he should have created a different series. It is sad and disappointing to portray a previously vigorous and proactive Doc when ever there was a crime, to a shallow side kick, more preoccupied with F1 than with crime, and yawning and sleeping when there is a murderer on the loose.
If there is a Book 4 I hope Gary Gerlacher reverses paths and goes back to AJ and Banshee as interesting, wholesome and strong willed as before.
Profile Image for Courtney.
323 reviews
September 24, 2025
Out of all his thrillers, I thought that this one was the best laid out. It seemed more realistic on Doc’s personality that he wasn’t the one solving everything all by himself. Overall, I found it to be very enjoyable.
68 reviews
March 15, 2025
Just finished this third book in the series! Although predictable in the fact that some mayhem will be found, and that Doc and Banshee will find themselves enmeshed in it. This one proves to be a fast paced read, with continued likable characters, a well thought out plot, and lots of twists and turns that make these enjoyable reads. Having worked in the ED myself, I enjoy the included ED “going ons”, and the expressed camaraderie and closeness between its staff. It really is a family second to none. Willl start the final and fourth book soon.
1,018 reviews14 followers
August 17, 2024
A.J. Docker, an emergency room doctor and his service dog are involved in a police matter. Someone placed a bomb in the hospital garage and a pregnant doctor was severely injured. Who would do this and why. Another bomb was placed elsewhere but found before too much damage was done. Follow the story as everyone in the city is in real danger as a big race day is coming up. Great and very likable characters. Can’t wait to read the next book due out December 2024.
10 reviews
April 12, 2025
I just discovered Doc and Banshee earlier this week. I just finished this, the third in the series. I've had a very enjoyable week! Early on in the first book, I grinned and said to myself, "I'm going to like him." I was right! Doc and Banshee and their various friends are the stuff good books are made of. I'm ready to start the fourth and last (at this point) in the series, and I just wish that Gary Gerlacher wrote as fast as I read!
18 reviews
November 25, 2025
My third book by Gary Gerlacher. I hope he never stops writing. His books would make great movies, but they may have a problem finding the right character for Banshee. Off to order the next book in his series now.
876 reviews3 followers
November 25, 2025
Doc and Banshee are currently working in Las Vegas. When a bomber, who leaves no clues leaves a car bomb that injures a pregnant doctor, Doc and Banshee become involved, as does his girlfriend Lana.
132 reviews
August 26, 2025
Really enjoy this series. I did prefer to the second one with the signature humor and more this time, which I welcomed laughing out loud on more than one occasion. I noticed there was less involvement with AJ and Banshee mid way through the story so a bit disappointed. Nonetheless, I will keep reading as I really love this duo.
134 reviews1 follower
June 14, 2024
Love this series! Crisp writing and great plots!

The Doc Docker and Banshee his trusty canine super hero buddy series is just so darned fun to read. Like chips, you just can't stop.

This latest adventure set in Sin City is a doozy. Billionaire gamblers, mysterious bombers, the usual chaos in Doc's ER work place and, oh yes, F1 racing in town just to keep things interesting. Robbery, bombings, assassination attempts, and babies. Just take my word that you will fall in love with this series. Just so much fun!
Profile Image for Dana Goosen.
140 reviews2 followers
July 31, 2025
2 - 1 > 1*

Sloppy plot (could see the real villain from afar). Sloppy editing (typos). Minus a whole star for a WHOLE DUPLICATED EPISODE FROM THE PREV BOOK WITH CHEERLEADING TWINS AND A BROKEN RIB/STERNUM?? How much lazier this writing and editing could go?
And of course lots of luck and lucky convenient coincidences instead of satisfying smart analysis and guesses.
Profile Image for Ivanka Fear.
Author 6 books69 followers
February 14, 2024
The third book in the A. J. Docker And Banshee thriller series is an action-packed medical thriller set in Las Vegas. With well-researched details, it delivers a realistic and entertaining story about a bomb threat in one of the biggest tourist areas in the U. S. Great descriptions of the Strip, downtown Vegas, and its casinos and hotels add to the appeal of the book.

Along with the dark topic and exacting descriptions of the fallout resulting from this criminal activity, the book offers readers a touch of humor and heart-warming interactions between characters. Alternating back and forth are hospital scenes with banter amongst the medical personnel, gruesome bomb explosions, the domestic life of Doc and his reporter girlfriend Lana, the killer’s actions, a Prince’s privileged lifestyle, and the police investigation. Suspense builds with each chapter as the connections between events and people are revealed.

Author Gerlacher keeps things interesting with various points of view and likeable characters. Partnerships in the medical field, law enforcement, and personal friendships were well developed. I appreciated the lighter tone depicted in scenes with Rick and Mac working alongside Doc, as well as the loving relationship between Doc and Lana as they work together to stop the bomber. Rick is a warm, caring counterpart to the psychopath with a selfish agenda. Lana is a strong woman, stopping at nothing to find a ruthless killer. Doc puts others ahead of himself both with his medical training and his foiling of the bomber’s plans. And of course, Banshee is the real hero of the story!

The accuracy of medical details and credible bomb threats mixed with genuine characters guarantees an unputdownable read. Buckle in and get ready for a fast-paced ride!
35 reviews
July 17, 2025
Las Vegas, the entertainment capital of the world, hosts an F1 race, the largest sporting event in the city's history and a prime target for terrorism. With over a half million people descending on the Strip for the event, a bomb detonated in a parking garage days before the race. In the emergency room, Doc fights to save the lives of a pregnant doctor and her premature baby injured in the blast, spurring him to risk his own life to find justice for the victims. He is joined by his girlfriend Lana, a smart, ambitious reporter, his friend and colleague, Rick, and his trained ex-police dog Banshee. Their investigation takes them from a seedy bar to iconic landmarks around Las Vegas and crescendos on the night of the race when chaos reigns in the city. As the sun rises, they reveal a deceptive scheme to close the case. An action-packed thriller, Sin City Treachery entertains with a story that leaves readers guessing until the end. Author Dr. Gary Gerlacher is an ER Physician. He describes some issues in medical terms. Very interesting reading with his medical descriptions adding to the book. Of course Banshee a retired K9 dog and his law enforcement training just at the exciting time is always fun to read. Story is well written and trying to guess who the actual suspect is kept me reading "just one more chapter before bedtime"
Profile Image for Daniel Burke.
Author 3 books46 followers
February 16, 2024
I had the good fortune of reading an advanced copy of this book. I hadn’t read the first or second books in the series before I read this one. It didn’t matter. No background reading required. This story stands on its own, and it is phenomenal. The lead protagonist, AJ Docker, is a terrific character. He is an adventurous, knowledgeable, and eminently likeable person who happens to be a Las Vegas emergency room physician who has a knack for private investigation and kicking ass. He’s also the owner of a super intelligent former police dog named Banshee. Along with AJ’s girlfriend, a sexy, tough-as-nails investigative reporter named Lana, AJ and Banshee must track down and stop a bomber who has chosen Formula One race week to cause multiple mass casualty events in Las Vegas. The bomber’s vile motives seem clear until they’re not.
The hero in this story, AJ Docker–Doc for short, is an MD, but this is not a medical thriller. This is a straight-up, action packed, private sleuth, police procedural, suspense thriller, expertly told by a practicing physician who apparently also possesses a deep understanding of law enforcement tactics and procedures. It all just feels very real.
Entertaining and shocking, you’ll be surprised where this one takes you.
70 reviews
July 1, 2024
Another fantastic story

Having !over in Las Vegas for several years, this kind of tugged on my homesick strings. Sunrise was just a pediatric hospital and as a retired paramedic I'm happy to hear they're a top trauma ER.

I don't know where Dr. Gerlacher gets his ideas for stories but I hope he never stops writing this series. Doc is such an enigmatic character with great skills and an even better moral compass. I love that he feels obligated to follow his feelings about helping his patients when something like this would happen. Aren't to many folks out there who'd get involved in a police matter of this extent, but as usual he's got a lady friend who,this time, is a reporter who will do anything to get to the truth and report it. And then there's the beautiful dog Banshee, a highly trained ex police K9 who was retired by the police in Houston and given to Doc by his friend, Banshee's handler.

I'm not going into detail other than dirty cops, murdered prisoner, wrongly murdered cop by dirty cop, 2 good detectives...and a very smart but not quite smart enough bad cop. You get a tour and history of Hoover Dam, a big F1 race in Las Vegas ..lots of twists and turns to keep you going until the end. I'm onto the next one...enjoy!!
Profile Image for Kay Smith-Blum.
Author 3 books68 followers
February 14, 2024
From the very first exchange about fiddle playing I was in - albeit because I grew up on the tunes of Doug Kershaw the legend - but Gerlacher engages his reader partners in the Sin City dance immediately and with a secure arm around your mind - he spins you thru a tale of deception, rich characters, dastardly deeds - my personal favs a toss up between Jen Schumer and Banshee - or maybe Lana who gets a foot massage when she needs it - but then again Rick’s new backflip is nothing to sneeze about - okay- okay - but you gotta love a guy who works Instagram posts into the plot :) Lots of great characters you won’t want to miss- especially - Banshee the world’s smartest and kindest dog - who it turns out can stand on his back legs with his front paws in the air - hands up? get it?!! So get it - especially if you want a great read and best of all - keeps you guessing to the very last - well almost last page. :) – Kay Smith-Blum, Author, Debut novel "Tangles," coming November 2024
20 reviews
March 7, 2025
I have read three of the AJ Docker books and working on number four. I think this would be a good script for a movie or TV. series. Having worked in the medical field for my career I appreciate the insight of Gerlacher's views as to the problems with the medical system as it stands now. He doesn't dwell on this but his occasional reference is noted. The U.S. spends more on medical care than any other modern civilization and have worse outcomes. We shouldn't be denied medical care nor should be go bankrupted in the process.
Anyway, about the books. Really enjoyed them. A little violence, romance and mystery. Great plots and really enjoy Banshee's role. As I read the books I wonder how he comes up with the plots/story.
I am sure some arise from his experiences as an ER doctor but obviously they go beyond what one would normally experience in the ER. Great books and I hope there are more to come.
Profile Image for Cam Torrens.
Author 5 books116 followers
February 14, 2024
An ER doc, a reporter, and a retired police dog walk into a casino…sounds like the start of a bad dad joke. Trust me—this bad-a#$ trio isn’t kidding around.

Evil lurks in Las Vegas and the police can’t figure out who is threatening the city during one of its largest events. From the heights of the Hoover Dam to the vaults of the Mandalay Bay Resort & Casino, the only ones making progress on this case are definitely no joke. AJ “Doc” Docker, his dog Banshee, and the intrepid reporter Lana team up in an attempt to save “the 24-hour city” and see justice done.

In this gripping third novel of the AJ Docker & Banshee thriller series, Gary Gerlacher once again proves he’s got the gift—an ability to create characters readers care for and plots so fast-paced you might need your heartrate checked by “Doc” in the ER.
34 reviews
May 23, 2025
fantastic storyline, great writing

This particular story of Dr AJ Docker’s sleuthing was quite interesting in offering detailed writing for each character’s role, versus more on Dr Docker’s point of view. The story and details grab the reader and take you on an incredibly detailed and well choreographed journey with nice twists, police investigation, police dog training, unusual heavy criminal technology, crypto currency and of course- medical science. The characters and events are so well written in detail for this novel and I enjoyed a repeat of previous characters seen in this book (the twins scene cracked me up).

It’s great Dr Docker has a special love interest again and it’s important that his character has grown. I do love the heavy use of humor in this book - and great work on the character banter!
51 reviews17 followers
February 14, 2024
Sin City Treachery is exactly what you want in suspense action fiction – fast pace, compelling characters, and a logical plot with enough surprises to keep you on the edge of your seat until the last page. Equal parts medical thriller and police procedural, author Gary Gerlacher deftly shifts the narrative between the main character physician AJ Docker and the events swirling around him. As a nurse, I especially appreciated the author’s ability to describe complex medical procedures clearly without oversimplifying them. Although this is the third in a series, it did not feel like I was jumping into the middle of a story. I’m planning to adding Gerlacher’s other novels to my beach reading list. Well done!
Profile Image for Janet Graham.
2,506 reviews11 followers
December 19, 2024
Awesome Vegas Thriller
This book is the third in a series that does not need to be read in order, although I am. Our main character is an Emergency Room doctor who stays in one place for a while and then moves on. His constant companion is a highly skilled, retired Belgian Malinois police dog. He is the star of the show and knows hundreds of commands which comes in very handy. This episode is set against the crazy backdrop of Las Vegas during the buildup to a weekend of Formula 1 racing. The story is a page-turner that goes very quickly. This is a clean story with no foul language, little violence, no gore, and no bedroom scenes. I have been enjoying this series and have been binge-reading it!
Profile Image for Christine.
302 reviews6 followers
June 7, 2025
This book was gobbled up in 2 days. The print is the perfect size for reading on my tablet. Sin City Treachery was an excellent fast-paced murder thriller and honestly would make a great movie. The main two characters are AJ Docker & Banchee. AJ is an ER doctor hence his nickname, "Doc" that travels on a 3-month rotation with his sidekick, Banchee who is a highly trained, retired police dog. Banchee has saved his owner's butt more than once just in this book alone. A short synopsis without major spoilers is a bomber is loose in Vegas during the weekend of the a big motor race. Police & FBI are racing against time to find the person before there are any more injuries & deaths. I give this book 5 ☆s. I look forward to more books in this series.
Profile Image for Mimi.
112 reviews
October 26, 2025
When I first started the series, I thought it was going to be fairly light-hearted. AJ is an emergency room doc who ends up with a retired police dog who was shot saving his life. That may be a little bit of a spoiler for the first one but it's the basis for the rest of the series. I've been very impressed with the writing, the detail, the research, and the excellent characters. This particular episode of the series takes place in Las Vegas and involves his relationship with a journalist, a very serious journalist, and a bomber. AJ and Lana do some things together which would not be ordinarily considered but they are both intelligent and brave. I can't really say much more without giving stuff away so I'll just say that it was really good and I can't wait for the next one!
Profile Image for Harveynics.
78 reviews
June 27, 2024
fun new series

This is the third AJ Docker book I have read and I have found each one enjoyable to read. These read like a fun action movie with a very likeable and able main character. Having an ex police dog sidekick just makes the whole thing better. This book combines some a/e drama with a serial bomber, Chinese billionaires and formula 1’s Lewis Hamilton - something for everyone. I also like that the main characters girlfriend is promoted as an extremely capable female journalist not reliant on his help but happy to let him join her investigation as he is invested when his colleague is seriously injured by the first bomb. Can’t wait for the next one!!
Profile Image for Paige Turner.
1,110 reviews22 followers
December 26, 2024
Another great read! The only thing I didn't care for is how the reporter girlfriend, Lana, was more dominant in this story with AJ and Banshee seemingly her sidekicks. Doc and Banshee should be the focus and the other characters secondary, in my opinion. I mean, AJ rubs her feet, waits on her hand and foot and even schedules her interviews? What does she do for him? Not much. And Lana is the one who saves the day? Anyway, that's just my opinion.

As a side note, in the FAULTY BLOODLINE, Docker's contract in Montana isn't up until July, yet in this one, it's October and it says he's been there 5 months. Oops!

Otherwise, I loved the book.
Profile Image for Cathrine.
1,153 reviews8 followers
March 26, 2025
AJ Docker and Banshee are in Vegas

And his new love is Lana, a reporter.

A pregnant, black doctor is severely injured when her car exploded in the hospital parking garage shortly after a bomb threat had been phoned in to 911. Another bomb threat was set to massacre the responders to the another smaller bomb that exploded when a mainly black children’s choir was singing at an outdoor venue. Someone wants the bombs to be attributed to white supremacist groups in the area.

Lana uses her resources as does her sidekick AJ to determine who is behind the bombings, seeming to stay one step ahead of the police.
Profile Image for Kay Green.
828 reviews
October 8, 2025
I just flew through this book. Set in Vegas, it is a mystery about a bomber who is determined to disrupt the city during the F1 Race - one of the biggest spectacles in Vegas. The three main characters were great: AJ Docker is an ER doctor who likes to solve mysteries, Lana is his girlfriend - a reporter who will do anything to find out what is behind a story - but the best character is Banshee - A trained police dog who is now owned by the doctor and saves the day more than once!! I loved seeing Lana get the scoop on the cops because of all her contacts! The body count was a little high for me, but still I will read more in the series. Highly entertaining!
Profile Image for BAMF_Book_Nerd.
121 reviews16 followers
February 17, 2025
Sin City Treachery is book three of the A.J. Decker Medical Thriller Series by Gary Gerlacher, MD. It's mind-blowing when you stop and think about what some individuals are willing to do and risk in order to live in infamy, which is why book three is my favorite in the series. And, of course, Banshee is still my favorite, loveable character. However, Lana's unwavering desire to discover the truth was an exceptional addition. I highly recommend this author and this series to anyone who enjoys reading thrillers.
6 reviews
February 23, 2025
Well written page turner

It usually takes me a long time to read any book as I tend to doze off after a while. However, not with this book. Organized into multiple short chapters allowed for breaks if needed. However, at each chapters end I wanted to see what happened next. There was just enough description of times and characters to understand all the twists and turns without becoming overwhelmed. Thus finished and enjoyed this book much sooner than other authors. Now onto third book of this series.
Displaying 1 - 30 of 303 reviews

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