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Quinn & Costa #5

The Missing Witness

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When a key witness goes missing, Quinn and Costa must find her before a killer silences her for good…

Detective Kara Quinn is back in Los Angeles to testify against a notorious human trafficker, finally moving past the case that upended her life. But when the accused is shot by a masked man in broad daylight, the chaotic scene of the crime turns up few reliable bystanders. And one witness—a whistleblower who might be the key to everything—has disappeared.

After the prosecuting DDA is stabbed to death, it’s clear that anyone who knows too much about the investigation is in danger, and tracking down the witness becomes a matter of life or death. With government corruption running rampant and someone on the inside trying to pin anything they can on Kara, she trusts nobody except FBI special agent Matt Costa and a handful of allies.

But when explosive secrets begin to surface within the LAPD and FBI, Kara questions everything she thought she knew about the case, her colleagues and the life she left behind months ago.

Now Quinn and Costa must race to find the missing witness and get to the bottom of the avalanche of conspiracies that has rocked LA to its core…before it's too late.

402 pages, Kindle Edition

First published January 23, 2024

654 people are currently reading
7978 people want to read

About the author

Allison Brennan

110 books5,303 followers
New York Times and USA Today bestselling author Allison Brennan believes that life is too short to be bored, so she had five children and writes three books a year.

In 2019, Allison relocated from Northern California to Arizona with her family and assorted pets. She loves baseball, hiking, family game night, and (of course) reading.

RT Book Reviews called Allison “a master of suspense” and her books “haunting,” “mesmerizing,” “pulse-pounding” and “emotionally complex.” She's been nominated for many awards, and is a three time winner of the Reviewer's Choice award winner for RT Book Reviews as well as the Daphne du Maurier award. Most recently, she was nominated for Best Paperback Original by International Thriller Writers.

With over 45 books and dozens of short stories, Allison is writing multiple series and the occasional stand alone thriller. Her most recent book out now is THE MISSING WITNESS, part of the Quinn & Costa series. In June Allison is launching a new Phoenix-set series about a family of private investigators starting with YOU'LL NEVER FIND ME.

You can reach Allison through Goodreads or her website.


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5 stars
2,227 (36%)
4 stars
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3 stars
1,090 (17%)
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69 (1%)
Displaying 1 - 30 of 513 reviews
Profile Image for Tracey .
905 reviews57 followers
January 31, 2024
This is an entertaining, well-written, fast paced, romantic suspense novel. It has a strong and capable female protagonist, murder, mystery, intrigue, suspense, corruption, secrets, twists and turns, and a satisfying conclusion. This is the fifth entry in Ms. Brennan's outstanding Quinn & Costa series, and can be read and enjoyed as a standalone. I listened to the audio version of this novel, and the narrator, Ms. Suzanne T. Fortin, does an excellent job depicting the characters and their personalities.
Profile Image for Jonetta.
2,600 reviews1,330 followers
October 29, 2024
the setup…
It’s finally time for Detective Kara Quinn to return to her home in Los Angeles, testifying against David Chen, a despicable human trafficker and the man responsible for her former partner’s death. His issued death threat for Kara forced her to leave town and work for the Mobile Response Team headed by Matt Costa. But only minutes before she was scheduled to testify, Chen is shot down by a masked man in front of bystanders. There was one witness, however, who recognized the shooter and she’s now missing. And, she just happens to be the whistleblower connecting Chen to deeper corruption within city government.

the heart of the story…
It may have started with human trafficking but the corruption was far more insidious, involving city government officials, members of law enforcement (city and federal) and funding for the homeless. Kara also has a target on her back as her nemesis, FBI Agent Bryce Thornton, is fixated on her and determined to bring her down. When the DDA she was working with was murdered right before her eyes, things got dicey as it was clear this case was far reaching. Who can you trust?

the narration…
I enjoy Suzanne T. Fortin’s storytelling skills and she’s my voice for Kara. However, she chose to use the same voice for the whistleblower and it got confusing as there were no transition indicators when there was a shift in points of view.

the bottom line…
It’s a complicated network of lies, subterfuge and corruption but I was able to keep up with the grift. What I wasn’t prepared for was the duplicity of those Kara should have been able to trust within her own department. That was a great twist I never saw coming. This was the showdown I waited for and it delivered. 4.5 stars

Posted on Blue Mood Café
Profile Image for Chris  C - A Midlife Wife.
1,833 reviews462 followers
December 27, 2023
So complex and layered but getting through the web is worth it.
~~~~~~~~~~~~~~~
Brennan developed this plot fresh from the California headlines in this much anticipated new release.

In the latest case of Quinn and Costa, we become embroiled in the corrupt city politics and the fight to bring those responsible for heinous crimes to justice.

This story becomes an addictive read with the complex layers and depth of the plot. The main characters fear trusting anyone with their complex case due to the deception and corruption, even within their departments.

Knowing who to trust in the tangled web becomes harder and harder with each turn of the page. But getting through and starting to see some clarity makes it all worth it in the end.

This book is not only a detailed suspense and thriller but it also is somewhat of a whistleblower case with the California homelessness issues open for the world to see. A shocking and saddening truth bomb that needs to be brought to light.

The Missing Witness is an amazing addition to the series. Quinn and Costa are two strong characters that I thoroughly enjoy reading and following. Brennan shows her fantastic writing skills with the intricate plot, complex characters, and highly detailed corruption that sounds more true than fiction.

Intense in spots with an ending that is everything we have been waiting for! I wanted to cheer!

I want more from this awesome team of characters!
~~~~~~~
* I voluntarily read and reviewed an advanced copy of this book. All thoughts and opinions are my own.
* full review - https://amidlifewife.com/the-missing-...
Profile Image for NILTON TEIXEIRA.
1,283 reviews644 followers
January 27, 2025
“The Missing Witnesses” (book #5 Quinn & Costa series), by Allison Brennan

3 stars ⭐️⭐️⭐️

Well, this was my 5th by this author within 30 days.
Once again this book didn’t feel that was written by the same author.
The storyline was interesting but overall the book felt too long.
It was nice to finally learn a bit more about Kara’s character and what happened to her before becoming a part of the FBI team.

I was expecting more backstory for all characters, as the previous books were too thin in that department. Catherine, the forensic psychiatrist/profiler, is practically non-existent in this book (she is present in one chapter).

The last 25% is probably the best part of the book, but unfortunately there was nothing remarkable about this work.

I’m rating it 3 stars because of the writing and storytelling (although I thought that the narrative was repetitive).

Like the other books in this series, this was borrowed from the public library.

The sixth book was recently released and I have ordered a copy. If it happens to be another 3 stars, then it will be my last book for this series. I may try the other available series, but not so soon.

e-book (Kobo): 416 pages (default), 107k words, 45 chapters

Profile Image for Anita.
2,652 reviews220 followers
January 21, 2024
I've lived in SoCal for over 70 years, and I have to say that I absolutely believe that something like the events described in this book could really happen, especially in Los Angeles. I'm a firm believer in Brennan's Homeless Industrial Complex. This book is complex, and the plot is complicated with lots of twists and turns although the baddies were known throughout the book. The suspense comes in how the good guys figure it all out. Matt and Kara grow closer together and I can't wait for the nest book.

Los Angeles Police Department Detective Kara Quinn had her life changed nine months ago when she was a part of a bust that when bad. David Chen, a human trafficker was captured but he is fighting the charges all the way. After a bounty of $1 million dollars is put on Kara's head, she is loaned to the FBI to get her out of town. She's back for a hearing in the Chen case and suddenly the case is turned upside down when Chen is murdered, and the only eyewitness, a whistleblower on her way to revel explosive information, is missing. When the DDA in charge of the case is murdered right in front of Kara, she knows that this case is about more than a human trafficker.

Matt Costa and Kara are determined to find out both the who and the why as this case reveals some deep corruption in Los Angeles government and they both know that there are some real bad actors in both the LAPD and the LA-FBI. Who do they trust, because trusting the wrong person could get them all dead.

My thanks to the Publisher and the Author for providing a complimentary digital Advanced Reader Copy (ARC) of this novel via NetGalley. This is my fair, honest and personal review. All opinions are mine alone and were not biased in any way.
Profile Image for ♥Rachel♥.
2,275 reviews924 followers
January 25, 2024
4.5 Stars

Kara Quinn has been called back to Los Angeles to testify in the case against David Chen, a human trafficker. Months ago, Kara went undercover to expose David Chen’s operation, bringing women in from China for forced labor in LA sweatshops. However, things go terribly wrong the night of the raid and Kara’s informant as well as her partner Colton are murdered. Kara was forced to relocate as David Chen put a price on her head. After assisting Matt Costa and his FBI Mobile Response Team back in the first installment, Matt arranged for Kara to come work for him on loan from the LAPD.

Now with the case against David Chen finally going to trial Kara’s days with the Mobile Response Team may be coming to an end. However, when Chen is shot the whole case starts to come undone. Kara, Matt, and Michael must piece together why Chen was killed and the plot is more complex and deeper than they imagined. Homeless assistance programs, corrupt city officials, leaks in the Los Angeles FBI office factor into their investigation. Plus, FBI Agent Bryce Thornton is still gunning for Kara's badge. They have an ugly history.

The Missing Witness was a crime procedural with many layers. Kara reunites with the LAPD, and it’s bittersweet for her. This is what Kara’s been working toward, a chance to get her life and career back in LA, but things aren’t as she imagined. Kara’s become attached to working with Matt and his team of agents, solving cases all over the US. She’s become attached to Matt as well, albeit reluctantly. Matt’s been a steady rock for Kara as she works through relationship issues. I’ve enjoyed seeing them draw closer.

Living in California, I’m disheartened to hear the story is based in part on the homeless crisis here. So many of the facts defy logic!

I love Allison Brennan’s brand of mystery/crime procedurals! She blends complex characters, their relationships, and current topics into a riveting mystery! I breezed right through, glued to the pages, eager to see how it all turned out! I’ve grown attached to all the characters on Matt’s team, each being fleshed out a little more with each installment. The series is best read in order.

A copy was kindly provided by MIRA in exchange for an honest review.
Profile Image for Robin Loves Reading.
2,899 reviews460 followers
January 25, 2024
LOS ANGELES – The 2023 Greater Los Angeles Homeless Count results were released today, showing a 9% rise in homelessness on any given night in Los Angeles County to an estimated 75,518 people and a 10% rise in the City of Los Angeles to an estimated 46,260 people.

A human trafficking case from detective Kara Quinn’s recent past reminds her how haunted she is by Sunny’s death. Sunny was instrumental when it came to Kara's trying to stop a trafficking ring. Now back in Los Angeles, Kara is set to testify against the person who was running the human trafficking in the case where Sunny was killed. Because of her impending testimony, there is a vendetta against Kara.

Then the story goes back and forth to Violet, whose mother is one of the victims of homelessness. Her mother is one, like many others, who fell victim to the drug epidemic. Addicts, as the book mentions, are on a “…slippery slope of desperation". It was impossible not to feel compassion for the people in this book, and of course, real life, which is why I included stats about Los Angeles above.

Even before the trial begins, the prosecuting DDA is stabbed, and this increases the danger that Kara is facing. It becomes patently clear that there is a high level of corruption and this places Kara's life at risk more than once.

There is a missing witness and both Kara and FBA SSA Matt Costa are determined to get to the bottom of things in this desperate case. Time. Time. Time. Will it run out?

Many thanks to Harlequin Trade Publishing and to NetGalley for this ARC for review. This is my honest opinion.
Profile Image for Becky.
523 reviews29 followers
October 8, 2023
When I say that I was excited to get an advanced reader copy of this book, that is an understatement. I started reading this series earlier this year when I received an advanced reader copy of the previous book in this series. It is now one of my favorites. Now that I have finished this book, I can honestly say that it just gets better with each new book.

This book answers all of the questions that started the series. Detective Kara Quinn helped take down a major criminal as part of the LAPD. In turn, her life was put in danger. She became a part of the FBI's new initiative, the mobile response team/unit. Kara is back in town to testify and help put the criminal she took down in jail. An event happens at the beginning of the book that turns the whole case upside down.

This book is excellent. There is a twist that I never saw coming. To be honest, this book is full of twists and turns at every corner. We get to see the Mobile Response Team, and they continue to grow and work together - so many great moments. I am not going to get into specifics about the plot - you need to go into this one blind.

My only complaint about this book is that it ended too soon - that is not a criticism. It is actually the highest compliment. I wanted more. This book could never be long enough for me! I am anxiously awaiting the next book in this series. I highly recommend that you start at the beginning of the series. You will not be disappointed!

Thank you to NetGalley and Harlequin Trade Publishing for the advanced reader copy of this book - I screamed when I received it! This book releases in January of 2024, so you have plenty of time to catch up on the rest of the books in this series. If you love great thrillers, mysteries, and procedurals, I highly, and I mean highly, recommend this book!
Profile Image for Brooke Nelson.
Author 3 books481 followers
dnf
January 2, 2024
Not rating because I don’t think I read enough for it to be a fair rating. I think I would enjoy this book more if I were a man.
Profile Image for Sabrina.
4,308 reviews2,397 followers
January 29, 2024
NOW LIVE!
Amazon US * Amazon UK

I've really enjoyed the Quinn & Costa series so far and I've loved getting to see Kara figure out her new path. But sadly I wasn't as intrigued with this book as I have been with the previous ones. I think it's completely a me problem and for some reason the storyline of what kicked Kara out of LA wasn't all that interesting to me. I did like getting some more insight into her character but she also felt unimportant to a lot of the story which was weird to me since she was the focus of the investigation for a good part of it. I'm still excited to see where she'll land next so I can't wait for more from this series
Profile Image for Jeanie.
3,088 reviews1 follower
January 4, 2024
There is entire business that will end when we solve the homeless crisis. It has become to political. Everyone arguing about the cause-drugs, mental illness, lack of housing, any number of things. Political because there is no accountability. Fraud and waste are built into the system, which is a scam it and of itself.

First of all before I get into this informative thriller, this is not a political in that it is about red vs blue, or blue vs red. It deals with the problems. Homelessness has gone up considerably over several years and California having the a third of the nations homelessness. The Missing Witness is a whistle blower of the corruption in politics, the police and FBI. How money and power reign in serious matters. Kara Quinn has come back to her own force to find the whistle blower and to determine what he/she knows. The body count is adding up.

I have read the whole series so I have come to appreciate Kara. She is vulnerable but keeps a wall around her heart for good reason. She is a walking contradiction which makes her relatable because in all honesty we all are. Kara comes to a cross roads with who and what she has been running away from in this case which it gives it another layer for me.

Regarding the whistle blower, he/she knows the pain of homelessness and the prison that it is. They attempt to reveal what the real cause of homelessness is greed. Knowing the billions of dollars thrown to solve the crisis and it keeps getting worse, you know that it is not about the people but about true oppressions.

Good job to Allison Brennan!

A special thank you to Harlequin Publishing and Netgalley for the ARC and the opportunity to post an honest review.

Profile Image for Elizabeth O'Keefe.
968 reviews23 followers
March 20, 2024
First time reading a novel by Allison Brennan, and didn't realize that this was a novel in a series (my library has it as a stand alone book). For not reading any of the other books, I was able to pick this up and know what was going on with the background of the characters.
3 reviews
October 11, 2023
The Quinn and Costa series continues. This book in the series ties up and answers a lot of the plot that has been building the entire series. This book is full of the on the edge of your seat drama that we have grown to expect from Allison Brennan. The WTF and HOLY MOLY moments in this book are everything I needed. There are also a couple of secondary characters that we get a little more back story on, which was done so seamlessly. This is now my new favorite book in the series. To the new to the series readers. This can be read as a stand alone, however I would not recommend it. The first few books go so much more in depth and the growth you see in Quinn is great. Especially in this book.
Profile Image for myreadingescapism.
1,286 reviews15 followers
August 4, 2024
I know I liked book 1 of the series but the other 4 books were so forgettable.


Honestly, I am still thinking about Monarch
Profile Image for Kat (Katlovesbooks) Dietrich.
1,532 reviews199 followers
January 21, 2024

3.5 stars

The Missing Witness by Allison Brennan is the fifth in the Detective Quinn and  FBI Agent Costa Series.

First, let me thank NetGalley, the publisher Harlequin - MIRA and of course the author, for providing me with a copy of this book in exchange for an honest review. All opinions are my own.


Series Background:    (Warning – May contain spoilers from previous books)
Under Assistant Director Tony Greer,  Special Agent Mathias Costa runs the new Mobile Response Team at the FBI. The goal is to travel to locations which have minimal law enforcement and offer their assistance. The team consists of Matt, analyst Ryder Kim, former Navy SEAL Michael Harris, forensic specialist Jim Esteban, Zack Heller, a white-collar crimes expert, and Forensic Psychiatrist Catherine Howard.  LA Police Detective Kara Quinn has been an undercover cop for 12 years, and since she is cannot return to LA at the moment, she is on loan to the FBI, and assigned to Matt's team.  Kara and Matt are romantically involved. 


My Synopsis:   (No major reveals, but if concerned, skip to My Opinions)
Kara is back in Los Angeles to testify against a human trafficker,  the case that turned her life upside down, and where she lost her partner and sometimes lover, Colton.  But when the accused trafficker is shot in broad daylight, there are few reliable witnesses, and the one who may help has disappeared.  They will have to find her before someone else does.

Then the prosecutor is stabbed to death, and things get worse.  The corruption in government,  the LAPD and the FBI is escalating, and trust has broken down between all departments.

Kara finds she has been lied to by her old department, and  is again being made the scapegoat.  She trusts Matt and his team, but few others.


My Opinions:
I'm going to be in the minority on this one, but, not every book is for everyone... I mean, it's a good book, but...

It's another drawn out book in this series.  That and the fact that it is again about police corruption has me wondering why I am still reading these books.  The last one had elements of it too, but this one is full political and police corruption. Definitely not my genre.  It felt like full-on hatred. The cops hated the FBI, and vice-versa.  Everyone lied, kept secrets, and everything of course, pointed to Kara.  It was so predictable. This is probably one of the reasons that these books seem so long...if you aren't enjoying the topic, the book is never-ending.  Another reason for the long story is the repetitiveness.  Way too much detail repeated again and again!

The story is told from multiple characters, which is normally fine, but the information is repeated from each of those perspectives!

Now for some good.  I do like Matt and his team.  Although Kara is often so unpredictable that she's hard to like, this book showed a better side of her.  However, I really have hope for the books because of Matt. He is a really compelling character.

Also on the good side, the author definitely did her research on homelessness.  So sad.  I enjoyed the characters of both Will and Violet, and that story-line was definitely interesting.

Admittedly,  I actually set this book aside, read something else, and then came back to it.  Now, if a third book in a row even hints at corruption, I'm out of here.  But I know a number of people will really enjoy this one!



For a more complete review of this book and others (including the reason I chose to read/review this book, as well as author information), please visit my blog: http://katlovesbooksblog.wordpress.com/
Profile Image for Darlene.
849 reviews6 followers
April 6, 2024
I’ve always been a fan of the Quinn and Costa series, and in my opinion this was the best in the series. Quinn travels to LA to testify against Chen, (a case that Quinn broke, and also sent her out East to work on loan to the FBI, and also to keep her safe from Chens threats to kill her). Costa and Michael are with her to protect her, and when Chen is killed they are all on high alert.
This book has a lot going on: Murder, political corruption, FBI and LAPD corruption, an informant some where in the mix. Quinn senses that the people she respected the most in the LAPD are lying to her. Quinn has always had trouble trusting people and realizes she has no idea how to love someone. I saw Quinn really grew up in this book and really like herself.
The ending wrapped up very nice and was very satisfying.
Profile Image for Emerald Bixby.
101 reviews4 followers
July 19, 2024
Has most of the makings of what I like about this series, and I imagine it'd yield some bits of satisfaction if I felt like spending the time to finish it. I was SO STOKED to finally be back in LA and following up on Quinn's main Backstory Case Situation Thing. But at four hours in, I'm just not excited enough to put up with the aspect I hate, that being the interspersed weird different first-person chapters where this new character Violet largely rants misguided dangerous bullshit that misrepresents the unhoused population (WE'RE NOT A FUCKING MONOLITH) and demonizes harm reduction (NO RATIONAL PROPONENT OF HARM REDUCTION IS CLAIMING IT SHOULD SUPPLANT OTHER MORE AMELIORATIVE INTERVENTIONS, STOP FUCKING LYING ABOUT METHODS THAT SAVE LIVES AND PREVENT EPIDEMICS, PEOPLE CAN'T EVENTUALLY BECOME RECEPTIVE TO REHAB IF THEY'RE DEAD, WHAT THE FUCK ALLISON BRENNAN).

I don't mind an agenda novel on principle, but I'm not gonna want to read it when the agenda is directly contrary to everything I study and stand for. I tried to compartmentalize my disgust, but the trash in those chapters just hits too close to my lived experiences and educational specialties, and is just plain fucking offensive to me professionally and personally, so it taints the whole experience. And Violet is too tangled in the plot for me to just skip those chapters, and even in the other chapters I find myself distractedly fixating on the misinformation imparted, so unfortunately my best option is giving up and moving on.

And, *besides* being packed with straight-up harmful anti-science stereotyping nonsense that perpetuates stigmas and infantilizes unhoused people and mischaracterizes harm reduction philosophy ... those chapters are also just an annoying weird vibe shift. (Obviously this criticism is more of a subjective taste thing, whereas my main complaint above is one I'll back up anytime with facts and logic.) For me, when a series is all in third-person, and there's no narrative context for first-person to be used (like someone writing or recording their thoughts in-universe), then use of first-person just feels incongruent and distracting. And so far no such in-universe context has been indicated, unless I missed something. Why am I hearing Violet's (well-meant and empathetic but also ignorant and patronizing) inner monologue? If we must inject a (bad, wrong) agenda, fine -- don't get me wrong, I'd defend to my literal death the author's right to say things I resent -- but why the weird frame shift? It just felt kinda icky immediately, well before I even realized I also don't like what the character herself says/how she's being narratively used.

I don't want EVERYTHING to be predictable of course, but I do like things to have clear consistent overarching parameters, and I hate it when those rules get established (especially over several books!) and then violated (or in this case Violeted, haaa). The creative choice to change in and out of third-person, both in this story and in other books where I've seen other authors do it, just feels way too disruptive and off-putting for me. Dear authors, please don't do that, auuuuugghh, I haaaaaaates it.

I'm sure I'll still check out the next installment when it shows up at my library. Hopefully these characteristics are a fluke; I've liked this author's stuff otherwise so far, or wouldn't still be reading her works. But alas, I guess I'll be learning how Kara Quinn's big complex built-up Ongoing Case Back Home wraps up by googling some plot synopsis somewhere. And that's a bummer.
Profile Image for Becky.
523 reviews29 followers
October 8, 2023
When I say that I was excited to get an advanced reader copy of this book, that is an understatement. I started reading this series earlier this year when I received an advanced reader copy of the previous book in this series. It is now one of my favorites. Now that I have finished this book, I can honestly say that it just gets better with each new book.

This book answers all of the questions that started the series. Detective Kara Quinn helped take down a major criminal as part of the LAPD. In turn, her life was put in danger. She became a part of the FBI's new initiative, the mobile response team/unit. Kara is back in town to testify and help put the criminal she took down in jail. An event happens at the beginning of the book that turns the whole case upside down.

This book is excellent. There is a twist that I never saw coming. To be honest, this book is full of twists and turns at every corner. We get to see the Mobile Response Team, and they continue to grow and work together - so many great moments. I am not going to get into specifics about the plot - you need to go into this one blind.

My only complaint about this book is that it ended too soon - that is not a criticism. It is actually the highest compliment. I wanted more. This book could never be long enough for me! I am anxiously awaiting the next book in this series. I highly recommend that you start at the beginning of the series. You will not be disappointed!

Thank you to NetGalley and Harlequin Trade Publishing for the advanced reader copy of this book - I screamed when I received it! This book releases in January of 2024, so you have plenty of time to catch up on the rest of the books in this series. If you love great thrillers, mysteries, and procedurals, I highly, and I mean highly, recommend this book!
Profile Image for Dawn.
387 reviews36 followers
January 23, 2024
The Missing Witness is the fifth installment in the wonderful Quinn and Costa series that just keeps getting better and better with each book. Allison Brennan’s storytelling is phenomenal, and I know I can’t get enough of this series and this author’s books. The reader has been waiting since book one, The Third to Die, when we got introduced to Kara, Matt and the rest of the Mobile Response team. It’s been leading up to this particular case of Kara’s and I know I am not the only one who was on teeter hooks to see how it would end up for her as well as for the FBI team she has been on loan with. The writing is top notch with so many twists and turns I really didn’t see them coming as I flipped the pages to see what is next. This is testament to the author’s wonderful storytelling. This is an author who knows how to craft a story filled with twists that will draw the reader in until the very last page.

We met Kara Quinn in the first book, The Third to Doe and I know I wasn’t the only one who found the prickly detective compelling and intriguing. I enjoyed each of the series books, but THE MISSING WITNESS puts them on Kara’s turf in Los Angeles and we finally see what happens when the trafficker is determined to see pay for his crimes finally face justice when it all goes sideways. The characters are what make this series such a wonderful entertaining read. They are flawed, complex people and the reader can’t help but find yourself rooting for them. I really enjoy Kara’s relationship with the FBI team as each book in the series kept it growing between them and the reader is shown how Kara is and why she is the way she was.

The Missing Witness is one wild ride right from the beginning to the last page. I am really hoping the author continues this series as it really is quite different from other FBI series I have read, and the characters continue to grow and learn with each book. If you are looking for an action-packed ride with compelling characters and a fast-paced storyline, then I highly recommend this series as a whole. I do recommend reading from the beginning as each book builds upon the end and we get to see the growth of the main characters with each book.
This entire review has been hidden because of spoilers.
Profile Image for LianaReads blog.
2,801 reviews246 followers
February 2, 2024
Allison Brennan delivers another gripping installment in the Quinn & Costa series with 'The Missing Witness.' Detective Kara Quinn's return to Los Angeles for a human trafficking trial takes a perilous turn when a key witness vanishes, throwing her into a vortex of murder, mystery, and explosive secrets.
Brennan's writing skillfully weaves a tapestry of suspense, keeping readers on the edge of their seats with unexpected twists and turns. The dynamic partnership between Kara Quinn and FBI special agent Matt Costa adds depth to the narrative, blending romance seamlessly into the heart-pounding suspense.
'The Missing Witness' is a well-crafted police procedural, featuring a strong female protagonist and a labyrinth of conspiracies. Brennan's vivid descriptions and fast-paced storytelling make this novel a definite page-turner, offering a thrilling and entertaining experience for fans of romantic suspense.

Very grateful to the publisher for this review copy, opinions are my own
Profile Image for Darcy.
14.4k reviews543 followers
January 25, 2024
With how this one started, it really didn't go where I thought it would. I also, didn't expect to see Kara be betrayed like she was, surprises all around.

I thought Kara was rightly pissed when she learned what she did and pissed at all the people. Her actions at the end, while extreme fit too. With how her life has been Kara needs to depend on those she works with and has in her life and that trust was broken in a big way. I'm glad that Matt figured out a way to make things work and that they are solid.

Now the crime, it disgusted me! At the center of things were greed and taking advantage of people that needed help the most. I was glad things were exposed and many were punished.
This entire review has been hidden because of spoilers.
Profile Image for Carolyn.
2,233 reviews
February 27, 2024
Powerful and intense. The writing in this entire series is superior work. Lots of secrets revealed in this one. NO SPOILERS! Catching my breath here. The best book in the series to date. And, please don't let it be the last! If you like smart mysteries, with lots of tension, fascinating and complex characters and a little bit of romance, I highly recommend the entire series.

On a side note, I have absolutely no doubt in my mind that the back story in this book (the homeless industrial complex, the people on the streets and those who profit off of them), exists. It's always about money and power. Sickening.
Profile Image for Cathy Nouwens.
31 reviews1 follower
April 2, 2025
Really love this series and all the characters. I think this was my favourite one yet.
Profile Image for Kari.
4,024 reviews95 followers
February 24, 2024
The Missing Witness is the fifth book in the Quinn and Costa series. This one finds Kara back in LA to testify against the person responsible for her having to leave in the first place. When he is murdered in broad daylight, one of the witnesses goes missing. Matt and Kara have to figure out what is going on.

Let me first warn you...Do NOT read this book first. It will spoil things for the first four books in the series. There is a major reveal in this one. That being said, I really enjoyed this one and have enjoyed this whole series. There are so many twists and turns and moving parts. I have enjoyed watching Kara grow over this series. Not only as a person, but in her relationship with Matt. I loved the ending! I'm not sure if this is the end to the series, or if Matt and Kara will be back. I really hope they will!
Profile Image for Sandie Bell.
301 reviews3 followers
February 20, 2024
Once again, Allison Brennan has hit it completely out of the park. Loved this so much. The twists and surprising turns will keep you on the edge of your seat from beginning to end. Can't wait for the next adventures of Quinn & Costa.
539 reviews1 follower
February 12, 2024
This was very well written and made one think about the city governments and how they are helping the homeless. This was a turning point for Kara Quinn in not only her career but in her life. There are layers to this story/plot ant he reader peels the layers as they the story.
Profile Image for Maria.
1,205 reviews16 followers
February 16, 2024
3.75 stars

Don't get me wrong, I really like Quinn & Costa, but the mystery in this one didn't catch my interest very well. Maybe it's because the problem felt so utterly American I just couldn't relate to it, or something, I'm not sure.

The "missing witness" gets her own POV and, sadly, I just didn't care for her at all. Her content, written in first person, dragged me out of the story somehow. Plus, to be perfectly honest: I didn't want to spend time with her - I wanted more quality time with Kara and Matt!

However, I thought the book fell a bit short on that front too. I wanted MORE Kara and Matt.
I wanted more one-on-one action. I wanted them to talk more. Work more together. Just spend time and scenes - together!
Instead, they were kept apart a bit too much and (to me) that's an utter mood-killer when it comes to this series, because its strength lies in the sizzling "Quinn & Costa" chemistry.

I just want to add that I feel SOOO relieved this might be the last I ever hear about Kara returning to her old cop job. Talk about living in total denial. Phew. So glad that's (hopefully) over!

All in all: Not a home-run of a book for me, but I will absolutely return for more. I was a bit worried for a while this would be the last book in the series, but thankfully, there will be more Quinn & Costa!
(Hopefully with MORE Quinn AND Costa.)
Profile Image for Marta .
279 reviews62 followers
October 5, 2025
I didn’t make any comments the first time(s) I listened to this book.
I really enjoy this series. If you have not read/listened to them at all, I suggest starting with the first. Although they can be done out of order, things might make a bit more sense with the continuation of characters if you go in order.

Suzanne T. Fortin does a good job narrating the book. Not a whole lot of changing with voices but there is enough that it isn’t just her reading the book to us.

The case that took Kara away from L.A. has finally brought her back. She is prepared to testify against a human trafficker, but before that can happen, he is murdered in broad daylight. (Not a spoiler alert). Everything goes a bit sideways after that. More bodies drop, a witness goes missing, and corruption seems to be everywhere.

Matt, Kara, and Michael must figure out who they can trust and who they absolutely should not trust before anyone else gets hurt and to get to the main source behind the corruption.

It was fun to see where it all started for Kara. There isn’t too much action from Ryder or Jim in this one, but we are introduced to agent Wagner.

A bit slower paced and because I have already listened to this I tuned a little bit out during some of the longer meetings. Great series though!

rating of 4⭐️’s posted: 4/19/23
Review and sort of revised rating posted: 10/2/25 3.5⭐️’s rounded up.
Fixed typo: 10/5/25
Profile Image for Susan McAulay.
465 reviews14 followers
January 20, 2024
Thanks to NetGalley for providing me with a copy of this book in exchange for my honest review.
The last third of the book is what made it worth reading for me. I am the outlier in that I honestly did not enjoy most of the book. However, when I finally was able to put the pieces together, I became much more invested. There were things about the book that I did not reduce my rating for because I think that they my shortcomings rather than the author's. It has been a while since I have read police procedurals and this author in particular and I suspect that I may not be as crazy about them as I used to be.
There were a few other things that bothered me that did impact my rating: one is that there were abrupt changes in character perspectives and that made the book hard to follow. That is why it was better later on when I was more grounded. The other is that there was a bit of preachiness about homelessness and while I agree with the sentiment, I don't like to be hit over the head with it. The book was strongest in its dialogue where some of this could come out, without feeling like I was being talked at. And I would say overall, dialogue was the biggest strength.
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