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There’s a killer inside all of us…

After an elite criminal profiling unit is shut down amidst a storm of scandal and mismanagement, only one person emerges unscathed. Forensic psychologist Doctor Alexander Gregory has a reputation for being able to step inside the darkest minds to uncover whatever secrets lie hidden there and, soon enough, he finds himself drawn into the murky world of murder investigation.

In the beautiful hills of County Mayo, Ireland, a killer is on the loose. Panic has a stranglehold on its rural community and the Garda are running out of time. Gregory has sworn to follow a quiet life but, when the call comes, can he refuse to help their desperate search for justice?

Murder and mystery are peppered with dark humour in this fast-paced thriller set amidst the spectacular Irish landscape.

311 pages, Kindle Edition

First published October 31, 2019

7758 people are currently reading
26785 people want to read

About the author

L.J. Ross

58 books3,351 followers
LJ Ross is an internationally bestselling author, whose books have sold over 7 million copies worldwide.

Her debut, Holy Island, was released in 2015 and became an instant, international bestseller. Since then, a further eighteen of her novels have gone on to take the coveted #1 spot, some even before general release and whilst only available to ‘pre-order’. The Bookseller magazine has reported on Louise having topped the ‘Most Read’ and ‘Most Sold’ fiction charts, and she has garnered an army of loyal fans who love her atmospheric and addictive storytelling.

Her eleventh novel, The Infirmary, is a prequel story to the DCI Ryan series and is available as a major Audible Originals audio-drama starring Tom Bateman, Kevin Whately, Bertie Carvel, Hermione Norris and Alun Armstrong.

The first novel in her Alexander Gregory Thrillers series, Impostor, was shortlisted in the British Book Awards 2020: Crime & Thriller Book of the Year. The audiobook of Impostor, narrated by Hugh Dancy, was also selected as a finalist in the New York Festivals Radio Awards, Best Fiction Audiobook of the Year Category.

In May 2021, Louise was shortlisted for the prestigious Crime Writers’ Association ‘Dagger in the Library’ award, which recognises an author’s entire body of work having been consistently enjoyed by library borrowers around the United Kingdom, and an author’s longstanding support of libraries.

Louise was born in Northumberland, England. She studied undergraduate and postgraduate Law at King’s College, University of London and then abroad in Paris and Florence. She spent much of her working life in London, where she was a lawyer for a number of years until taking the decision to change career and pursue her dream to write. Now, she writes full time and lives with her husband and son in Northumberland and Edinburgh. She enjoys reading all manner of books, painting, travelling and spending time with family and friends.

To find out more about the many philanthropic ventures Louise has founded and sponsored through her publishing imprint, Dark Skies Publishing, please visit ‘Philanthropy’.

If you would like to connect with LJ Ross, she would be very happy to hear from you:

https://www.facebook.com/LJRossAuthor
https://twitter.com/ljross_author
www.lovesuspense.com
lj_ross@outlook.com

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Displaying 1 - 30 of 1,317 reviews
870 reviews27 followers
October 25, 2019
Before we get down and dirty with this book, let's address the elephant, (or should I say 'male god') in the room; a certain Hugh Dancy - narrator. Is it fair to say that with that face he's wasted as a narrator? He should be a supermodel, or replace the Statue of Liberty, or marry me, (I prefer option 3). His voice matches his looks, smooth and sophisticated, like hot, melted chocolate. If I tell you I took LJ Ross to bed, but imagined Hugh Dancy - will you judge me? Actually, I don't care, because I did and it was the best threesome I've had, ever! Impostor is a work of art. She's a wily one that Ms Ross. I was hooked from about word 8. Alexander Gregory is a divine creation, he's sitting at my right at my next imaginary dinner party. We've only touched on his back story, I feel I know him quite well but am chomping at the bit to become better acquainted. Off he flies to County Hoo-Haw, a rural community with barely a need for a part time police officer, to help sort out a bizarre murder. And here is where Ms Ross' conniving really comes to the fore. As each new character is introduced I was sure I had solved the murder as every single person became a credible suspect. There were so many red herrings I was worried I might slip on one on my way to the fridge. When Dr Gregory had obviously figured it out and I hadn't I became frustrated that I couldn't listen quicker! What a denouement it was - I'm not saying more in case of spoilers, but I had been listening whilst on my way to a GP appointment and had to stop the nurse calling an ambulance because my pulse was racing so fast. Then just when you breath a sigh of relief at the epilogue and are thinking, "That was brilliant", in Ms Ross storms again with a contrivance of such inventiveness you may find steam escaping from your ears. So, in conclusion, 7+ hours of hot, melted chocolate poured into your ears by a male god who was supplied by a genius writer who's pen should be registered as a lethal weapon. Would I recommend Impostor? That's like asking if I recommend breathing; of course, I don't just recommend it, I'm telling you that you NEED it in your life! So quickly, buy it now. You can thank me later.
Profile Image for Alan Cotterell.
562 reviews189 followers
January 9, 2020
Wow, that was a fantastic start to a new series. When I first heard there was a new series by the author I first thing was does that mean no more DCI Ryan. But thankfully not the case.
Dr Alexander Gregory is an elite forensic psychologist and profiler. With a unique insight and skill set. I was hooked from page 1 and not let go until the end . Even them book 2 description has me hooked.
Not one word was wasted, in this, wonderful emotive and descriptive piece about a small Irish town and it's people with a psychopath amongst them.
I think I have my first contender for book of the year, it will be tough to beat. Deserves more than 5 Stars.
Profile Image for TheConnieFox.
470 reviews
January 12, 2026
The “Imposter” novel is the first book in the series of the Alexander Gregory Thrillers! This is a dark and mysterious psychological thriller that was really good! The setting is in a small town, where forensic psychologist Dr. Gregory gets involved with a murder case. While Gregory does this, he also starts to deal with his own darkness and secrets. This book comes with a lot of twists! Some of which I saw coming and some that I did not see coming at all.

It is a fast paced thriller that is both character and plot driven. This comes with some content warnings, please be sure to check them out and stay healthy. I found this to be easy to read and follow! I will definitely be reading the other books that come out in this series!

I think that if you love a good gripping mystery, along with psychological elements, you will enjoy this book! Overall, I rate this novel a 3 out of 5 star rating!

This gave me “The Whisper Man” by Alex North vibes. Thank you to NetGalley, author L.J. Ross and Poisoned Pen Press for this eARC in exchange for my honest review. All thoughts and opinions expressed are my own.

The release date is February 3, 2026! This is a revised edition.
Profile Image for Carolyn.
2,770 reviews757 followers
November 25, 2020
This is a great start to a new series featuring forensic psychologist. Alexander Gregory currently works in a high security psychiatric hospital in London but was previously part of a now disbanded psychological profiling unit that worked with the police. The murder of a young woman in a small town in County Mayo has the local Gardai scratching their heads trying to find clues or motives and Alex is asked if he could provide a profile of the likely suspect.

When Alex visits the murder scene and talks to the Gardai he believes that the well planned killing and staging of the victim, a well-loved mother and wife, suggests someone local hiding in plain sight who suffered great trauma when they were young. But with no fingerprints or DNA evidence left at the scene or that of a second murder it's hard for the Gardai to narrow down who in their community might be guilty.

I don't know enough about psychology/psychiatry to know if a profiler can determine so much about a suspect from studying the crime itself but it makes an interesting premise for a crime series. As well as Alex's interactions with the police, we also see him at work in the psychiatric hospital, in particular in sessions a very difficult patient who killed two of her children through Munchausen's syndrome. He's an unassuming character, empathetic and not at all arrogant, who listens to those around him, although suffered from childhood trauma himself. I look forward to getting to know more about him as the series progresses.
Profile Image for Linzie (suspenseisthrillingme).
887 reviews991 followers
February 5, 2026
In the great tradition of classic crime fiction, Imposter took us behind the scenes of a tense murder case. This time, however, there was a twist of a criminal profiler-turned-sleuth as the narrator. Smart, empathetic, and yet also believably flawed, his character was a shining piece of this quick, easy read. On top of that, though, was a layered plot centering around a small Irish town. With standard village vibes, it made for an everyone-is-a-suspect kind of a read. I do have to say that the large number of credible suspects as red herrings kept me from guessing who the serial killer really was on my own. Revealed in a brilliant twist that I never saw coming, it was both perfectly set up and also hidden with care. To be frank, it was the perfect kind of revelation for this whodunnit lover.

All said and done, despite a jarring amount of “head-hopping” in the narration, I still inhaled this book in one single sitting. Coming in at under 300 pages and with plenty of short, cliffhanger chapters, I couldn’t stop my fingers flying through the pages at speed. I mean, not only was there quite a bit of introspective storytelling that made me connect with Alexander, but the last half of the novel was an action-packed race as the police tried to get their man…or woman. Don’t get me wrong, it had a definite Golden Age charm despite the serious crimes as it felt somewhat softer than many modern-day thrillers. So if you like your crime fiction with a psychological edge, grab this first book in a newly re-released series. It was a super fast read that I couldn’t put down. Rating of 4 stars.

SYNOPSIS:

In the remote hills of western Ireland, fear spreads as the locals struggle to make sense of a killer who is seemingly one of their own...

Dr. Alexander Gregory, a psychologist recovering from the collapse of a high-profile criminal profiling unit, wants nothing more than a quiet life to finally sit and think things through. but his rare ability to understand the minds of violent offenders makes him hard to ignore―especially when a small town is shaken by a brutal murder. Reluctantly pulled into the case, Gregory finds himself confronting not only a cunning predator, but the darkest corners of his own mind.

Thank you LJ Ross and Poisoned Pen Press for my complimentary copy. All opinions are my own.

PUB DATE: February 3, 2026

Content warning: child abuse, suicide, murder, stalking, heart attack, alcoholism, mention of: death of a child
Profile Image for DeAnn.
1,781 reviews
February 3, 2026
4.5 surprise find
*now available

The premise of this one sounded good to me, a psychologist who also works on criminal profiling and a case in Ireland. I found myself very invested in this one, and I read it quickly.

A troubling murder of a young mom has the local Garda in a small Irish town stumped, and the townspeople are worried. The mayor asks Dr. Alexander Gregory to consult on the case.

I really liked the doctor’s character. He has a previous failed endeavor in profiling, so he’s a bit cautious going in. He gets involved in the case's politics. The mayor has two sons who are heading up the case. Everyone knows everyone in this small town. That makes it troubling when Dr. Gregory builds a profile showing the killer is an insider, likely someone who lives in the town. Now everyone is more anxious.

We also get some insight into the doctor’s work at the hospital in London. He really wants to help people. But he’s also in agreement with the police and courts punishing those who commit crimes. I found him to be a fascinating character!

I thought I had this one all figured out, and I was totally wrong! It was quick-paced, and I finished it in almost one day. I can’t wait to read the next one in the series.

My thanks to Poisoned Pen Press for the opportunity to read and honestly review this one.
Profile Image for Clemens Schoonderwoert.
1,366 reviews132 followers
March 1, 2025
**Read 4.25 STARS!**

This remarkable crime story is the 1st volume of a new series called the "Alexander Gregory" thriller series.

At the beginning of the book you'll find a very appropriate phrase taken from Sir Arthur Conan Doyle's "The Boscombe Valley Mystery", along with excellent storytelling by the author, and which includes also a cast of very lifelike characters, these important ingredients make this book about a psychopathic murder committed by a person who's living in a fantasy world and carrying burdens throughout his/her life, a great read.

The book starts off with a prologue set in 1987, and events which will occur then with his mother and younger brother Christopher will concern our main protagonist Dr Alexander Gregory, forensic pathologist and occasional profiler, and will shape him as a person and a specialist in the future, especially when he has a patient called Cathy Jones and his relationship to her will be known at the end of the book.

In the main story set in 2017, Dr Alexander Gregory, forensic psychologist at the Southmoor Hospital in London, is called in to act as a criminal profiler for a murder committed in Ballyfinny, County Mayo, Ireland, and so assist the local Garda, brothers Niall and Connor Byrne in particular, in an attempt to find the killer of this murder.

Along the way one more killing will follow, and Dr Alex Gregory is able to find a kind of pattern and the reason of these killings, until in the end Alex and Niall Byrne will be to apprehend the surprising impostor killer, who's an organised but unstable kind of person at the same time, while Alexander Gregory will be confronted with some sad home truths of his own at the Southmoor Hospital, a home of the mentally very sick.

What is to follow is a well researched and action-packed psychological thriller, with a wonderful storyline and ending with a well executed plot, and where some home truths will be revealed in the end, both in Ireland and England.

Highly recommended, for this is an exciting begin of this new series, and that's why I like to call this first episode: "An Engrossing Psycho Killer"!
October 6, 2020
Imposter is one of the more aptly named books I have ever read.

Alexander Gregory was once, supposedly, a member of an elite psychological profiling group but is now serving as a psychologist in a hospital for the criminally insane, to use an old moniker. The author, however, appears to know nothing about psychology or psychologists. I feel comfortable in saying this because I spent my career working in applied psychology having received my doctorate from a quite well known university.

I read about 60% of the book and was determined to complete it but, it was so badly done that I was unable to push myself to do so. L.J. Ross' failings included, but were not limited to the following. He seemed not to understand the difference between a psychologist and a psychiatrist and sometimes used the terms almost interchangeably. His protagonist, Gregory, operated as an investigator and did not, in the portion of the book that I read, use any psychological or profiling principles with which I am familiar. He did, unfortunately, use only the most simplistic forms of "pop" psychology of the type found in the many so-called self-help books written by charlatans and TV show hosts.

The "therapeutic" approach used by Gregory in working with his patients was, at best, comical and at worst, ridiculous. In fact, the so-called therapist was downright hostile at times and at others, was just inappropriate. All in all, the portrayal could best be as wretched.

Having said all of that, I will admit that the story was interesting and I really did want to stick with it long enough to find out who the murderer was but I lacked the tolerance.

Over and Out
Profile Image for Nikki Lee.
630 reviews584 followers
December 15, 2025
Hawt diggity dawg, this book was such a BANGER! I mean, impossible to put down! I got this at the Bouchercon Conference in September, and boy, it’s been one of my favorite finds from there! 🤩

Dr. Alex Gregory is a psychologist and a phenomenal profiler who works in a hospital for the criminally insane. He gets called to Ireland for a murder case where a mother is meticulously staged.

As more bodies start to pile up, Alex works hard to catch a ki.ller with the Ireland Garda. The hunt is on ….. and man, is it ever!

Alex Gregory is such a fascinating character! My favorite thrillers are ones that feature psychologists and psychiatrists. He has the ability to step inside your mind.

This story kept me guessing NONSTOP! I kept changing my mind. There’s nothing like a thriller that holds you hostage and this is the one!

Perfect for fans of Michael Robotham and Helen Fields! Don’t miss out on this stellar psychological thriller!

5 ⭐️⭐️⭐️⭐️⭐️

Pub date 2/3/26 in the US
Profile Image for ♡❀Caroline. K❀♡.
126 reviews32 followers
Review of advance copy received from Netgalley
February 3, 2026
Impostor is the first book in the Dr. Alex Gregory series, and honestly, I’m excited to read the rest of the series after how much I enjoyed this one.

Dr. Alex Gregory is a psychologist who previously worked as a profiler, but after that unit collapsed, he began working with patients who have committed crimes. When a small town becomes desperate to solve a murder, Dr. Gregory is called in to bring his profiler expertise to the case.

This was a well-paced mystery/thriller, and I didn't find myself bored at any point. Dr. Alex Gregory was an intriguing character. I felt like I was right there with him, trying to figure out what was really going on. Overall, this was a solid 4-star read.

I want to thank Netgalley, Poisoned Pen Press, and L.J. Ross for the eARC. All options and thoughts expressed in this review are my own.
Profile Image for Sarah.
2,972 reviews232 followers
November 17, 2019
Oh my days! From the opening pages of this book, I was well and truly hooked.

I don’t want to say to much to spoil it for others but I was very much intrigued with the thread to do with Cathy Jones. The whole thing to do with her fascinated me and could understand to a certain extent why Alex seemed to be almost obsessed with her.

Now I don’t know about you, but I am as intrigued as to the why’s, than just the who. Why do people kill? So for me, having a main character who is a forensic psychologist couldn’t have sold this book to me more. Whilst you feel the urgency of stopping a killer and finding out who is behind it. I knew that through Alex, we would also spend time on the why’s. Saying that though, when we find out who the killer is, wow I was blown away. Literally!

Impostor is an absolutely fabulous start to a new crime series. I loved it, loved it, loved it! It started brilliant and the ending totally messed with my mind. The journey in between just made for a compulsive read. Omg I am so excited for book two!

My thanks to the author for a readers copy of this book. All opinions are my own and not biased in anyway.
Profile Image for Chris  C - A Midlife Wife.
1,841 reviews463 followers
November 27, 2025
I love police procedurals if they are written well. I especially enjoyed this one as the profiler is the leading character, and we start to get to know him along with the case he is working to solve.

The author created a fabulous twisty small-town murder mystery that is tough to put down. The main character is complex and reluctant with his gift. From psych hospitals to crime scenes, this is a compelling and suspenseful read.

The setting is perfect and pulls the reader in along with the secondary characters. Ross developed this story with precision and enough psychological suspense to keep the tension at the perfect pitch.

Imposter is a compelling and twisty read not to be missed. I cannot wait for more from this author. Plus, I need to go back and read her other works, too! Adding to my Best Of list!

~~~
* I voluntarily read and reviewed an advanced copy of this book. All thoughts and opinions are my own.
* Full review - https://amidlifewife.com/impostor-by-...
Profile Image for Matt.
4,894 reviews13.1k followers
November 28, 2025
First and foremost, a large thank you to NetGalley, L.J. Ross, and Poisoned Penny Press for providing me with a copy of this publication, which allows me to provide you with an unbiased review.

L. J. Ross is an author new to me, but whose writing has long been entertaining readers. After an elite British profiling unit is closed down, a number of highly-skilled individuals scatter across the United Kingdom. Back in academics and private practice, Dr. Alexander Gregory is free when the Garda need assistance with a murder in County Mayo. Dr. Gregory is one of the UK’s most talented psychologist who is often able to assess the minds of the most intense killers. While Dr. Gregory is hesitant, wanting to focus on a quiet life, he agrees to take a crack at things, if only to provide needed guidance. As the investigation gains intensity, Dr. Gregory will have to stave off suspicions that he only wants to be in the spotlight and show his abilities, as the body count increases. L.J. Ross delivers a strong series debut.

I am always eager to discover new thriller authors, particularly those who can hold my attention with a strong crime element. L.J. Ross delivers a strong story that keeps the reader focused on the crimes at hand while using an Irish setting as a stunning backdrop. The story builds with a variety of narrative techniques, each of which enriches the larger story. Momentum pushes things along as the mystery envelops the reader, with chapters providing an edgy spin. This series debut keeps the reader curious and eager to read on.

Characters are impactful as their backstories connect well with ongoing development. Readers are presented varied personalities,
allowing them to see all moving parts while trying to solve the case at hand. Many characters are able to push the plot along while flavouring the piece with their respective layers. Ross did well with her character development and has me eager to see where Dr. Alexander Gregory is headed with the next novel.

Surprises are core in a police procedural or thriller, as it creates an entertaining foundation. Balancing twists and surprises adds something more to the reading experience. The reader may ponder the unpredictable while trying to solve things in short order, alongside Dr. Gregory. Ross keeps story on edge and drops some crumbs to keep the reader wondering, while they eye the second novel in this series. I cannot wait to see what Ross has in store for Dr. Gregory and everyone involved.

Kudos, Madam Ross, for a great series debut thriller.

Love/hate the review? An ever-growing collection of others appears at:
http://pecheyponderings.wordpress.com/
Profile Image for Miss✧Pickypants  ᓚᘏᗢ.
506 reviews69 followers
January 15, 2026
This book is being re-released in 2026 after first being published in 2019. It is the first in a series that now seems to be up to 6 novels (per amazon). Not sure what is behind the rebranding as though it is a new release but this renewed push is how I came across it when it was presented to me as an ARC. I did get a thrill out of the story despite it not really being a brand new release.

The story follows an English forensic psychologist who gets asked to do some profiling for a murder case in a small Irish village. Given it is a murder mystery, no spoilers here to ruin the fun for other readers. What I can share is the characters are interesting, from the psychologist tormented by bad dreams to the meticulous murderer. I really appreciated the way that the murderer is presented, it kept me guessing who they were right up until the reveal.

The author has another successful series so existing fans are probably already aware of this book. But if not, they and anyone who enjoys a solidly good murder mystery series will want to check out the first novel of this re-branded series.

Disclosure: Received an uncorrected ARC of this book from NetGalley and Poisoned Pen Press/Sourcebooks (Thank you!) in exchange for an honest review.
Profile Image for Mairead Hearne (swirlandthread.com).
1,203 reviews98 followers
Read
October 29, 2019
Unfortunately it was not a book for me.

I read Impostor to completion but, being Irish myself, I was a bit surprised at some of the inaccuracies about Ireland within the text and the story line.

The plot line was interesting but I just could not get beyond some glaring errors, in particular the continued reference to the Garda, used as the plural. It should read An Garda Síochána or the Gardaí. Also the Catholic church does not have Sunday School and the likelihood of a mayor of a small town in Mayo contacting a profiler in the UK for assistance in a murder inquiry over the heads of the local Gardaí just did not sit well with me.

Not for me I'm afraid.....
Profile Image for Cititor Necunoscut.
477 reviews92 followers
January 6, 2020
La sugestia unei prietene am încercat ceva scris de L.J. Ross, o scriitoare populară în UK și nu regret deloc alegerea. Am ales o serie, cum alta, în care personaj principal este dr. Alex Gregory, psihiatru de meserie, cu un trecut într-o ramură a criminalisticii care încă stârnește controverse: profilul criminalist. Deducem că a colaborat în trecut cu poliția ca profiler și cazul a eșuat, iar el și echipa lui au devenit țapi ispășitori. Alex Gregory este un personaj destul de complex, cu propriile schelete în dulap, iar printre detaliile din anchetă vedem și câte ceva din ce se întâmplă la locul său de muncă, un spital de psihiatrie. Când o tânără mamă, iubită și respectată de întreaga comunitate din micul oraș Ballyfinny, County Mayo, Irlanda, este ucisă într-un mod brutal, cu totul atipic, primarul orașului, mama a doi dintre investigatorii orașului, îl cheamă pe dr Alex Gregory în ajutor (nu știu cât de credibil este acest lucru, dar neavând tangențe în acea zonă, mi se pare un mic, mic detaliu). Și când dr. Alex Gregory intră în scenă, ai impresia că nu s-au schimbat prea multe în cei 100 de ani dintre acțiunea din Alienistul lui Caleb Carr și prezentul lui L. J. Ross în privința atitudinii anchetatorilor față de spijinul primit de la psihiatrii.

Cartea are acțiune, are consistență (deși este destul de scurtă pentru un thriller), are personaje frumos construite. Și are un sfârșit bun și surprinzător, chiar și după câteva sute de thrillere citite. Cu siguranță este o serie la care voi fi atentă în continuare.

Pentru această carte am ales varianta audiobook și vocea naratorului este pur și simplu magnifică. Apoi cauți și tu pe google, să vezi cine poate avea așa o voce și îl vezi. Păi să te mai concetrezi pe acțiune?? Și accentul irlandez...

description
Profile Image for Laura.
413 reviews113 followers
December 22, 2025
I really enjoyed this thriller!! I really hope it's a start to a series, as I feel it could absolutely grow into something great. It's a story of a psychologist that has done some profiling in his spare time, and he is asked to consult on a case. There are so many suspects, and trust me, you won't figure it out. And, there's an extra twist at the end you definitely don't see coming!

Thank you to Net Galley and Poisoned Pen Press for allowing me to read this ARC in exchange for my honest review.
Profile Image for Amy K.
114 reviews14 followers
September 25, 2025
This was an ARC read for me.
The Imposter was good and I enjoyed the read for the most part. I wasn't turning pages like a fiend to get to the end, but I did wonder who the killer was and how things would weave together. My struggle was with the interchangeable use of Alex and Gregory. It felt extremely inconsistent to me that in the course of a page the main character could be referred to as Doc, Doctor, Alex, or Gregory. Add to the fact that it is two FIRST names and it just got aggravating. In the first few chapters I had to keep reminding myself it wasn't two separate characters.
Profile Image for Michael --  Justice for Renee & Alex.
297 reviews256 followers
February 6, 2026
Against the starkly beautiful, windswept backdrop of County Mayo, Ireland, L.J. Ross's “Impostor” delivers a deliberately measured psychological mystery that succeeds as a profound character study and a promising launch for the Alexander Gregory Thriller series

The narrative centers on Dr. Alexander Gregory, a renowned criminal profiler and forensic psychologist. He sought a quieter existence after closing his elite London profiling unit, but his solitude is abruptly shattered when a gruesome murder rocks the small, rural Irish town of Ballyfinny. The baffled local Garda are forced to request Gregory's expertise as an outside consultant, relying on his unique insights to solve the case.

His presence, however, immediately ruffles feathers. Gregory—a London-based Englishman—is seen as an intruder, especially by the local community and the police officers handling the case, who are, notably, the mayor's sons. As the body count rises, Gregory’s profile suggests the killer is an "insider," escalating the town's fear into a deep-seated suspicion of one another.

Dr. Gregory is presented as a complex and flawed character, whose personal secrets and recurring nightmares add an engaging layer of self-doubt to his expert analysis. His past connection to a patient at Southmoor High Security Psychiatric Hospital in London, a mother who killed her own children, haunts him and hints at a deeper personal storyline that adds depth to his character.

The town is brought to life by its richly drawn characters, whose secrets, suspicions, and Irish humor hit the mark. This is evident one night when an elderly man leaves to frequent the local pub, telling his seventy-three-year-old wife, “Save those kisses for me,” with a wink. “I’ll save them for Cillian Murphy,” she muttered in reply, then fiddled with the remote until the small corner television displayed the newest episode of “Peaky Blinders.”

Maintaining an intricate pace, Ross skillfully incorporates numerous twists and potential suspects, alongside detailed police procedural elements. The novel offers a profound exploration of the psychological underpinnings of crime, delving into the motivations of murderers and the techniques of forensic profiling. This sustained, building suspense holds the reader's attention throughout, ultimately leading to an unexpected revelation of the killer's identity.

"Impostor" is the inaugural novel in the Alexander Gregory Thrillers series and serves as an excellent launchpad for the character's subsequent international cases. It is highly recommended for anyone who appreciates character-driven crime fiction and profound psychological depth over high-octane action, marking a compelling start to what promises to be an excellent international thriller series.

Thank you to Poisoned Pen Press and NetGalley for providing an advance reader copy in exchange for an honest review. #Impostor #NetGalley
Profile Image for Stephanielikesbooks.
720 reviews84 followers
January 31, 2026
I loved this police/forensic psychologist procedural!

The main character was believable and likable, the pacing was excellent, there were red herrings and several suspects who could have been the murderer. The plot twists were absolutely great, including the one near the end. In addition, the author got the small-town feel just right and I loved the Irish setting. The use of criminal profiling was very interesting and added a nice depth to the story.

This was the first in the Alexander Gregory thriller series, published in 2019. There are six books in the series and I will definitely be delving into books two through six.

Don’t miss this stellar read!!!

Thanks to the publisher for this complimentary digital copy. All opinions are my own.
Profile Image for Ken Kirkberry.
Author 10 books30 followers
December 26, 2019
LJ Ross new series (a departure from DCI Ryan), the Impostor introduces forensic psychologist Doctor Alexander Gregory. Gregory’s day job is looking after patients at Southmoor Hospital in London but, he is called to assist the County Mayo police by profiling a killer. His last case did not go so well therefore. Gregory applies himself with increased determination to see this one through.
Gregory is a complex character and will butt heads with other people, the town mayor and the head the Garda make a difficult start to his investigation. There is a sense of a typical small town where everyone knows each other, but maybe not as well as they think. Easy flowing story with surprises along the way and the standard unexpected twist at the end.
Profile Image for Mandy White (mandylovestoread).
2,809 reviews869 followers
Review of advance copy received from Netgalley
December 27, 2025
LJ Ross is an author that I have been meaning to read for a long time now, so thank you Poisoned Pen Press for sending me a copy of Impostor. This is the first book in the Dr Alexander Gregory series and I am happy to see many many more books available on Kindle Unlimited. If you enjoy a good police procedural with compelling characters and stories then you will enjoy this book.

Alex is sent to a small rural town in Ireland to help the Garda solve a murder. Nothing much ever really happens here and they need all the help that they can get. Alex is forensic psychologist and can read a criminal mind better than anyone. The locals don’t want to believe that one of their own could have done this, but with Alex’s guidance they start to see the evidence.

This is a fast moving story that I devoured in a few hours. It certainly kept me guessing and I was pointing the finger at almost everyone by the end. The ending was very clever and shocking.

This version is published on February 3rd, but it is out now in Australia and the UK.
Profile Image for Carolyn Walsh .
1,919 reviews562 followers
February 2, 2026
Thanks to Netgalley and the publisher for this gripping psychological mystery. I was unfamiliar with author L.J. Ross's previous detective series and was pleased to be introduced to his writing through an ARC of a new series featuring a fresh protagonist. Dr. Alex Gregory is a forensic psychologist and criminal profiler working at a London Hospital for the criminally insane. A unit for profilers had been started there, but was abandoned due to errors. Dr. Gregory emerged from its failure due to his stellar reputation. He tends to get involved in investigations while profiling, as his primary interest is justice for the victims. He has been studying a woman, Cathy, whose diagnosis of Munchausen syndrome by proxy led to the death of two of her three children.

Dr. Gregory has been assigned to a beautiful small town in Ireland, where everyone knows each other. They are frightened that a serial killer may be targeting them, and strongly believe it must be an outsider. On arrival, he is met by the village mayor. Her two sons are police officers who have been unable to solve a mysterious murder case. Claire Kelly's body was found by her husband and child. She had been laid out in an arranged, staged scene, and more murders are dreaded. The two police officers accept his help as a profiler. Gregory studies the clues and concludes that the murderer was from the village.

I thought the names caused confusion and disrupted its steady pace, but the tension never let up. Sometimes the lead character was referred to as Gregory, Alex, Alexander, or Doctor. Two of the prominent female characters had names starting with C, and I had to pause reading to avoid confusion. Dr. Gregory had a troubled background, often reflected in his dreams and nightmares, and I wished for a different way to address his past. The story is told mainly from Gregory's perspective, but is sometimes interrupted by others reflecting on his work. The ending contains a twist and draws all threads together in a satisfactory manner.

I found Gregory memorable as the lead character, and I enjoyed his role as a profiler. I hope The Imposter is the first of a new series, and I am interested in following him in future books. Publication is scheduled for February 03/2026.
Profile Image for Kerry.
669 reviews43 followers
October 23, 2019
WOW! What a start to a new series!!
Those who know me well will know I’m a massive fan of LJ Ross and her DCI Ryan Mysteries. I was SO excited when I discovered there was going to be a new series featuring forensic psychologist Alexander Gregory and I couldn’t wait to read it. It will be released on 31st October and you are in for a real treat!
A quiet town, with a close-knit community, in Ireland is shocked by the devastating death of a young mother. She has lost her life at the hands of another and it’s clear her murder has been planned and meticulously executed. This was no random act of violence.
Alexander Gregory’s help is requested as a profiler and although reluctant he decides to assist in any way he can. Nothing could prepare him for what he was about to become involved in, but his expertise proves to be crucial in finding this killer.
Nothing could prepare me for that ending! SO clever!
I loved the characters in this book, some very complex. I loved learning more about Gregory. I loved the setting, the whole everyone knowing everyone’s business (or thinking they do) aspect of a small town. The disbelief that one of their own could be capable of such horrific crimes is very believable. There is such depth to the characters that LJ Ross writes so they very easily seem like real people to me. The plot and twists throughout the story are genius, but the characters really make it for me. Once again, I was instantly drawn in and invested in their stories.
This is another book which commanded my attention from the very first to the very last page and I will have no hesitation in recommending it to anyone. I can’t wait for book 2!
A big thank you to LJ Ross for my review copy.

https://chataboutbooks.blog/2019/10/2...

36 reviews
August 29, 2020
I'm really not sure what the positive reviews are all about. Perhaps they are related to the fact that the book is available for free via Kindle Unlimited but if I had paid for this book I would be deeply unhappy. Cumbersome writing, clunky dialog, poorly written characters. The plot is twisty and quite compelling - with both Alex Gregory's 'home' life and the plot in Ireland providing some satisfaction -but a plot alone does not a satisfactory read make. I can't recommend using your time on this book with so many better-written crime novels and series available in the world.
Profile Image for ♥Rachel♥.
2,285 reviews925 followers
February 6, 2026
Dr. Alexander Gregory, a forensic psychologist, is called to the quiet town of Ballyfinny, Ireland, to help profile the killer of a young mother. The crime is chilling in its strangeness, almost no evidence, no clear motive.

Alex is a clever character I enjoyed the methodical way he helped the police zero in on suspects by examining the motive of the crime. His profile really helped, but there were several that fit the parameters.

Running alongside the Irish investigation is a second storyline involving one of Alex’s patients at the high security hospital in England where he works. The dual threads were equally compelling.

Impostor
is a gripping crime procedural that pulls you right into the investigation. I love mysteries where you feel like you’re piecing the clues together alongside the experts, and this one delivered. The final reveal shocked me, not just the truth about the killer, but the twist involving Dr. Alex himself. I’m absolutely continuing the series.

I voluntarily read an advanced readers copy courtesy of the publisher. These are my thoughts and opinions.
Profile Image for Sheila.
3,172 reviews128 followers
October 11, 2025
I received a free copy of, Impostor, by LJ. Ross, from the publisher and Netgalley in exchange for an honest review. This is book one of the Alexander Gregory Thrillers series. Dr. Alexander Gregory is a forensic psychologist. There is a killer in County Mayo, Ireland, can Dr. Gregory help catch them? This was a good thriller, perfect for a Halloween read.
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