The Missing Witness
Written By Allison Brennan
Published By Harlequin Trade Publishing
Release Date January 23, 2024


“When a key witness goes missing, Quinn & Costa must find her before a killer silences her for good”

There are many mystery writers out there but in my opinion, Brennan is one of the best authors. With an ability to keep the reader engaged and focused, she writes amazing books with characters that are developed and resourceful. This is book 5 in the Quinn and Costa thriller series yet it can be read as a stand-alone novel. This is a gripping mystery that keeps the reader on the edge of their seat wanting more and waiting for something that will possibly give away who the murderer is. Brennan leaves no bread crumbs here and without the predictability that some are accustomed to when reading a mystery/thriller, they find themselves reading well into the night or day in order to figure out whodunnit. This is yet another roller coaster of emotions that you will certainly not want to miss.

This one is full of action that will keep you breathless. No secrets here though…….. you need to run out and get your copy today.

5 huge stars


Thank you to the author, publisher, and NetGalley for giving me a copy to read in exchange for my unbiased and honest review.

I didn’t realize that this book is part of a series when I picked this book up. I enjoyed the book and now need to go start from book one. I thought the writing was smart and interesting.

Thank you to netgalley for a copy of this advanced readers copy.

Here is another wonderful Quinn & Costa adventure. I love this series. Brennan's characters are rich and her writing tight. The background of this story is a societal problem that appears to have no solution - how to help the homeless. This book was a pleasure with plenty of action and a kick-ass female lead. I like the romantic tension between Quinn & Costa. Readers who like Karen Rose or Karen White will love this thrilling novel.

I so enjoyed this series but this one I struggled to finish. I started and stopped many times. Too much on the corruption dragged the story down for me.

This is hands down my favorite ever Allison Brennan series and that's saying a lot b/c I'm already a huge fan of all her books. Just when I thought the series couldn't get any bette r- this book does it. Can't wait for book #6.

This was another great one from Allison Brennan. Well told and well written. I love how it was unpredictable and kept you guessing. Excellent book

Allison Brennan has been one of my favorite authors.. And of course this book did not disappoint!!! I loved this series and I was absolutely unable to put this book down!!!

Thank you NetGalley!!

I love @abwrites’ Quinn & Costa crime thriller book series. The fifth book in this series is The Missing Witness. In this book, Detective Kara Quinn finds herself back in LA after being called in to testify against the human trafficker that put out a hit on her. Unfortunately, once in LA there is a cascade of events that put Kara in danger and her current FBI team investigating widespread corruption. I enjoyed the themes surrounding government corruption and the pandemic of homelessness especially in California.

I love this entire series and this book which is full of action, a great plot twist, and was hard to put down once I started reading it. If you love police procedurals, then I highly recommend reading this book and series!

Thank you @_mira_books_ for allowing me to read this book in exchange for my honest review.

(This same review was shared on the Barnes & Noble website)

I love it. I really love this one. I'm a fan of this Quinn & Costa series. Love this badass couple.

What I love:
- Quinn & Costa of course. Perfect partner. Perfect for each other. I root for this couple from the beginning.
- The mystery. I love the betrayal, who's the mole, who's the bad cop/agent, what's the motive. Collecting evidence and following clues. Yup I love it.
- The Plot. Didn't see that coming but what a good surprise.
- The Red Herring. Love it, it keeps me guessing.
- The action. Always love a thriller with a great action.
- The feelings. I can feel everything what Kara's feelings, from frustrated, upset, angry to pretty sad.

What I don't like: predictable at some of the plots, but it didn't take away all the fun.

Recommended: yes, if you love S.W.A.T or The Rookie, I think you will love this series.

I love this series and I love Allison Brendan's writing. These books are so good and they keep you guessing until the end. I love them! This was a great book. 5 star read!
I just reviewed The Missing Witness by Allison Brennan. #TheMissingWitness #NetGalley
[NetGalley URL]

Thank you to Harlequin Trade Publishing and to NetGalley for this ARC for review.

I acknowledge that this is a well-written book, I do have reservations.

This installment in the series feels drawn out, much like its predecessors. Moreover, the predominant theme of police corruption leaves me questioning my continued interest in the series. While the previous book hinted at such elements, this one delves deeper into political and police corruption, which is not a genre I typically enjoy. The pervasive animosity between law enforcement agencies, the predictability of Kara being targeted, and the repetitiveness of the narrative contribute to the feeling of the story dragging on unnecessarily.

Despite these drawbacks, there are some positives to highlight. I have a fondness for Matt and his team, and although Kara's character can be erratic at times, this book does offer glimpses of her better qualities. Additionally, the author's thorough research into homelessness adds depth to the story, with characters like Will and Violet providing compelling storylines that resonate with readers.

I must admit that I set this book aside at one point to read something else before returning to it. If the next installment in the series continues to focus heavily on corruption, I may reconsider continuing. However, I recognize that many readers will find enjoyment in this book, particularly those who appreciate gritty crime dramas.

This is normally one of my favorite series, but I did not enjoy this story. I had a hard time staying engaged with the story. I just could not connect with the characters or the plot, & it moved really slow for me. It happens, you can't like them all. If you like this series, you should definitely read this one. If you are thinking about trying this series, you should start at book 1. It was really good.

While I do my best to make sure my reviews are spoiler-free, I may inadvertently reveal information that can help you connect plot points. So, here’s my TL;DR spoiler-free review: A solid 5-star police procedural/romantic thriller from a seasoned writer with lots of twists and turns. Do yourself a favor and read the first 4 books first.
If Lindsay Boxer and Kinsey Millhone had a love child, her name would be Kara Quinn. She is prickly, unlikeable, and works best alone. She’s also fiercely loyal, hardworking, smart, and feisty. She faces parental disappointment, but not for your typical reasons. Kara’s parents were con artists, so she did an about-face and became a cop. As an undercover agent, she’s developed few attachments outside her squad. Until her identity is leaked to the media and she’s forced to go on loan to the FBI’s Mobile Response Team under the command of Mathias “Matt” Costa. She and Matt develop a romantic relationship, and Kara learns that she can be part of a team… most of the time.
Now in The Missing Witness, Book 5 in the Quinn & Costa Series, Kara is home in LA to put an end to the human trafficking trial that changed the trajectory of her career. We pick up shortly after Seven Girls Gone. David Chen is out on bail and has placed a $1 million bounty on Kara’s head. Assistant Special Agent in Charge Bryce Thornton from the LAPD branch is still making problems with the backing of Assistant Special Agent in Charge Rebecca Chavez. Things escalate quickly when David Chen is murdered, and the only witness is a whistleblower on her way to expose a coverup within the LA Government. Violet is a computer geek with a personal connection to the growing drug and homeless crisis going on in LA. When she witnesses the murder, she disappears. Kara’s hunt for Violet leads to unexpected consequences, and forces her to confront what she thought she wanted versus what she knows she needs.
There are so many twists and turns in this book that I was actually surprised, which is hard sometimes since I’ve read so many thrillers/mysteries. I am also extremely hopeful that there will be more books in the series. Matt has a bad premonition about what will happen if James isn’t locked up for a long time.

The MRT also sees some new additions, such as FBI SA Sloane Wagner, a former Marine who goes undercover in Chavez’s office. I really hope we get to see more of her character since this book only touched on the surface. There’s also Nina Radinovich, the Assistant US Attorney and district attorney who hip-checks Chavez when she gets pushy about Kara’s alibi for Chen’s murder. You can just tell she’s a badass and I hope we get more of her. Brennan’s writing is so layered, and the story is so well-constructed that this was hard to put down.
While the story is billed as a romantic thriller, I would call it more of a police professional thriller with a side of romance. Matt and Kara‘s relationship is the absolute definition of a slow burn. And while I give it 1.5 spicy peppers for a heat reading, it’s pretty tame as far as a romance novel goes.
All in all, I love, love, loved this book! It’s no secret that police romance books are my absolute favorite, especially if they have multiple agencies and offices. I feel like I should know these characters (Lex?) from her other books, but honestly, it’s been so long since I read them that I can’t remember. Maybe at some point I’ll get to go back and re-read them.

Here’s hoping for more books in the Quinn & Costa series.

Allison Brennan's "The Missing Witness" seamlessly integrates into its series, making it accessible even for newcomers like myself. Once I dove in, I found it hard to put down.

The story follows Kara Quinn, who returns to LA to testify against David Chen, a human trafficker she had gone undercover to expose. However, things take a deadly turn during a raid, leaving her partner dead and Kara needing to relocate for her safety. Now, as Chen's trial approaches, Kara's time with the mobile response team, led by Matt Costa, draws to a close.

But when Chen is murdered before trial, Kara, Matt, and their team find themselves entangled in a web of deceit. What seemed straightforward becomes more complicated as they uncover corrupt officials and leaks within the FBI. The investigation twists and turns, revealing that even those they once trusted may be involved in the conspiracy.

Brennan crafts a gripping narrative filled with suspense and intrigue, keeping readers hooked until the very end. "The Missing Witness" is a must-read for fans of the series and newcomers alike.

Thank you NetGalley and Allison Brennan for the eARC of The Missing Witness. I really love this series with Quinn and Costa, this one did not disappoint. I am happy that Brennan tied up the ongoing investigation in LA, but there seemed to be an excessive amount of characters that were hard to keep track of. Looking forward to the next one in the series, with perhaps the addition of Sloane.

Could the Detective Kara Quinn series get any better? The answer is yes! In The Missing Witness by Allison Brennan, Detective Kara Quinn is summoned back to Los Angeles to testify against a notorious human trafficker. Plans change when a masked shooter takes the case into their hands. When the key witness to the shooting disappears, the reader is taken on a ride of masterful storytelling and the craftsmanship of a true detective caper. Kara is left questioning everything she thought she knew about the people around her, the details of the case, and her past.

No quotes because ARC

One Line Review: A case that changed the course of a detective’s life and career, and her efforts to move past are turned upside-down when secrets, murders in plain sight and betrayal shakes her to her core.

Synopsis: Returning to Los Angeles and hoping to close a metaphorical chapter of a book, Detective Kara Quinn is once again immersed into a world she was forced to leave to protect her own life. Having to testify against someone who is known as a human trafficker is difficult enough. When that person is gunned down in plain sight in front of the courthouse, and the witness to this subsequently goes missing, Kara is once again forced to question everything she knows, in a corrupt world, built to hide the truth.

My Thoughts: I made the mistake of reading this book first, learning a little ways in that this was book 5 in a series (entirely my fault) and there was an incredible amount of catching up to do. That being said, I still thoroughly enjoyed this book! Allison Brennan does a fantastic job highlighting and showcasing the homelessness problems our larger cities are experiencing, and the people in power who don’t necessarily put human lives in the forefront, rather exploiting them for their own gain.

Wow... what an amazing thrill to read!! I loved the writing style and I also loved that Allison Brennan kept you in suspense the whole time. Must read!

3.5 stars rounded up.

This story was a whole lot of government and law enforcement that wasn’t prepared for. It had a great storyline and I enjoyed the characters. But some of the law and political jargon was hard for me to follow at first.

Thanks to Netgalley and the publisher for this eARC.

The Missing Witness is the fifth and final installment in the Quinn and Costa series, a thrilling saga of crime, corruption, and romance. In this book, LAPD detective Kara Quinn and FBI agent Matt Costa face their most dangerous and personal case yet, as they try to find a missing witness who holds the key to a deadly conspiracy.

The book starts with a bang, as Kara returns to Los Angeles to testify against a notorious human trafficker, only to witness his assassination in broad daylight. The only clue to the killer's identity is a whistleblower who has vanished without a trace. Kara and Matt must race against time to find her, while dodging bullets, betrayal, and bureaucracy. Along the way, they discover shocking secrets that shake their trust in each other and the institutions they serve.

The Missing Witness is a fast-paced and gripping read, with twists and turns that keep you on the edge of your seat. The author does a great job of weaving together multiple plot threads and characters, creating a complex and realistic picture of the dark side of LA. The book also tackles some timely and relevant issues, such as human trafficking, homelessness, and police corruption, without being preachy or sensationalist.

The main strength of the book, however, is the relationship between Kara and Matt, who have grown and evolved throughout the series. Their chemistry and banter are undeniable, but they also face realistic challenges and conflicts that test their bond. Their romance is not a fairy tale, but a hard-earned and satisfying reward for their courage and commitment.

The Missing Witness is a fitting and satisfying conclusion to the Quinn and Costa series, and a must-read for fans of Allison Brennan and the genre. It is a book that will keep you hooked from the first page to the last, and leave you wanting more.