electrifying and thrilling thriller that was very enjoyable. i found the protagonsit a very effective character, and tracking down the murderer was certainly w.ell written. 4 stars. tysm for the arc.

If you are a fan of Sherlock Holmes, Dr. House, or Will Trent, you will want to read this. This is not a cozy mystery; there are some graphic descriptions of the crimes that might be shocking if you are new to the thriller genre. As a seasoned thriller reader, though, they are pretty mild.

The main character, Gardner Camden, is neurodivergent and possibly autistic (probably) but is NOT portrayed in a cheesy, stereotypical way. The other characters were distinct and easy to keep track of. The pacing was steady and quick.

I'm excited to see there will at least be a sequel but I'm hoping there will be demand for many more! This is EXACTLY the type of book I reach for when I'm not quite sure what I'm in the mood for and I can't wait to recommend this one to anyone who'll listen!

I absolutely adored this book - 5 STARS - the main gist of the book centers around a group of "misfits" within the FBI that are tasked with trying to solve a series of murders. The characters were well written and the book flowed well. I hope to see additional books with these characters

An elite division of the FBI is tasked in finding a serial killer who is murdering serial killers. An intricate plot with likeable characters made this a page turner for me. I loved seeing quirky characters portrayed in such a positive light.

Agent Gardner Camden is part of the FBI’s elite PAR unit (patterns and recognition). Camden excels at solving puzzles and along with a mathematician, a sharp shooter and a computer analyst the group makes the task force continue like clockwork. Now they are faced with their toughest challenge yet: the murders of bad men.

Head Cases is a good solid crime procedural in which team of investigators works tougher to solve elaborate puzzles. I enjoyed the continual action (and misfortune) as they worked their way through cat and mouse scenarios with the perpetuator. The PAR unit is sure to remind Criminal Minds fans of the BAU (behavioral analysis unit) and it is written here excellently. If you are a fan of detective/police thrillers, this book will be right up your alley. I enjoyed this one and rate it four stars.

I received this advance copy from the publisher via NetGalley in exchange for an honest review and feedback.

This was such a fun read/listen. The intricate plot kept me interested the entire time, and I never guessed what was going to come next. The characters were all very interesting. I would love to watch this as a TV series; it felt a little Dexter-esque. I will definitely be interested in continuing this series. Solid 4.5 stars.

An elite division of the FBI is tasked in finding a serial killer who is murdering serial killers. An intricate plot with likeable characters made this a page turner for me. I loved seeing quirky characters portrayed in such a positive light.

Head Cases follows a group of FBI agents with unique skills who solve tough cases that no one else can. Someone is killing other serial killers (🤯), and this group is tasked with finding them.

Overall, I really liked this one. I’ll never say no to a book about serial killers, and this was a fast-paced read that kept me engaged. I loved the PAR unit members and their mysterious backstories.

Head Cases reminded me a lot of Criminal Minds, but if the team was lead by Dr. Spencer Reid (which is a huge compliment BTW).

This book comes out on January 28 - definitely recommend checking it out! (Thank you @minotaur_books for the #gifted copy)

Sign me up for any future releases of the PAR Unit sequels—this is my new obsession! If you’re a fan of FBI dramas, Criminal Minds, or Profiler, and you also enjoyed the sharp wit of Slow Horses, you’ll love this book. The PAR Unit is a unique, unconventional FBI team made up of socially awkward, underrated, yet highly skilled individuals who struggle to follow rules and office politics but excel in solving the unsolvable.

The only thing missing from this book is a touch of sarcasm. If you’re expecting an eccentric, narcissistic leader like Jackson Lamb (brilliantly portrayed by Gary Oldman in Slow Horses), you won’t find one here. But don’t worry—FBI Agent Gardner Camden, the main protagonist, is far more likable and relatable. Unlike Lamb, Gardner is younger, clean-cut, and doesn’t rely on greasy food or alcohol to function (and yes, his socks are hole-free as far as I can tell!).

Gardner is a truly unique character. Socially awkward and possibly neurodivergent, he’s a master of puzzles, able to see patterns others miss. He is dedicated to doing what’s right, even at great personal cost—dividing his family, losing full custody of his daughter, and sacrificing his promising career. But given a second chance, he’d likely make the same choices. Now, he works with a team of outcasts in Jacksonville and only gets to see his daughter, Camila, for a few days at a time. She lives with her grandmother in Miami, who openly despises him for reasons Gardner can’t dispute.

The team members of PAR Unit are just as compelling. Cassie, Gardner’s partner, recently transferred after an incident with her previous superior and is as detail-oriented and brilliant with numbers as he is. Then there’s "The Shooter," a blonde, eccentric weapons expert who might just be my favorite team member. Frank, their leader, gives off "younger Denzel Washington" vibes but seems to take a back seat to Gardner on this case for mysterious reasons.

Rounding out the team is Richie, a dark-haired, highly skilled rookie in his mid-twenties. Suspiciously, his personnel file is sealed, something that quickly catches Gardner’s attention.

What makes the PAR Unit so extraordinary is their ability to detect patterns and solve puzzles ten times faster than the average FBI agent. Unfortunately, their colleagues call them “Head Cases” behind their backs, and the unit is at risk of being shut down. Their current assignment—a cryptic and high-stakes case—could make or break their careers.

A serial killer with a God complex is targeting other serial killers who escaped justice, killing them in the same gruesome ways they murdered their own victims. This killer thrives on puzzles and patterns, and he’s determined to draw Gardner into a dangerous game. Gardner must outthink the killer while refusing to play by his rules. Thankfully, he has a team of out-of-the-box thinkers to help him stay one step ahead and dismantle the killer’s plans. But can they win this deadly game of cat and mouse?

This book is a smart, fast-paced thriller with well-rounded, unconventional characters and an exhilarating plot. The satisfying conclusion left me urgently wishing for a sequel!

I’m giving this five stars for its nerdy, quirky, and brilliantly unconventional team!

Many thanks to NetGalley and St. Martin’s Press/Minotaur Books for sharing this brilliant crime thriller’s digital review copy with me in exchange for my honest thoughts.

Thank you so much for the ARC of Head Cases! The description caught my eye as John is a new to me author. This book was awesome and kept me turning the page to see what happens next. I’m a huge fan of crime and this book gave off serious criminal minds vibes, so if you like crime shows or books, this book is for you! There were a lot of descriptions and scientific words and police jargon that may be more than the average person wants, but my nerdy heart LOVED it all! I enjoyed learning about Gardner and PAR’s abilities to solve cases. I can’t wait to hopefully learn more about the teammates background and see what case(s) come in the next book! Thank you again for the ARC of Head Cases!

This was a fantastically fast paced police procedural. I always forget how much I love police procedurals until I read a really great one like this. From the get go we are trying to figure out the identity of the serial killer who is killing serial killers. Dexter style. That fact alone had me 100% in. The PAR (Patterns and Recognition) Unit has a group of remarkably bright agents who are able to solve cold cases and cases other agents can't solve with their brilliant brains and knack for figuring our difficult puzzles. Agent Camden is placed as Head Investigator on their latest case and I really enjoyed the story from his point of view. I also enjoyed his family/personal story and how it impacted his decisions and career. This story was so fast paced and had me on the edge of my seat towards the end. I loved how I was always wondering who did it, especially when the clues indicated it could be someone in the FBI!

Thanks to NetGalley and St. Martin's Press for my ARC of this story which publishes 1/28/25.

If you are a fan of Criminal Minds and Dr. Spencer Reid, this book is for you. The main character, an FBI agent with the PAR unit, is assigned the cases that can't be cracked. It's time for action for the group that usually gets delegated the cold cases and desk jobs. I enjoyed the cat and mouse aspect and all of the different characters with different skill sets. This one was fun.

This is my first thriller of the year, and it did not disappoint! It’s the first book of a new series by this author, and I am very excited to read his backlist now. Plus, it's been optioned for a TV series!

The story follows a group of FBI agents who are a part of the PAR group (Patterns and Recognition) who are looking for a vigilante murderer intent on seeking his own justice. The lead agent is Gardner Camden, a quirky character who is a genius with an affinity for puzzles. Right up my alley! I thoroughly enjoyed his character and the way his mind worked. He is super smart, but the plot was easy enough to follow.

This book will keep you on the edge of your seat! It is a propulsive game of cat and mouse and I couldn’t get enough. Keep in mind that there are some gruesome murder descriptions in the book, although it wasn’t overdone for me. It contains many tense and exciting moments, and I was very happy that the book contains a minimal amount of profanity, which can be unusual for some thrillers. But it’s always a plus for me.

This is a book to watch for this year and one I'd easily recommend!
4.5/5 stars

A special thanks to the publisher, St. Martins Press, Minotaur and NetGalley for the advanced electronic copy of this book in exchange for an honest review.

Calling all Criminal Minds fans! Have I got a book for you!

Head Case is about a serial killer killing serial killers. What more could you ask for? Sent on the case from the FBI, is the outcast Patterns and Recognition (PAR) unit. At the helm of this investigation is FBI Agent Gardner Camden, an analytical genius who hasn't met a puzzle he can't crack. As the murders keep piling up the killer starts to play a cat and mouse game with Agent Camden, leading to deadly consequences.

Although John McMahon has written other thrillers, this is my first book by him. I can easily say it won't be my last. I found myself surprised by the ending of the book, which I don't say often. I didn't see the killer's identity before it was revealed. I read quite a few thrillers so I can usually pick out the killer really quickly. That wasn't the case in this book. If body horror doesn't work for you, this book may not be for you. It seriously felt like I was back at the BAU on the hunt for a serial killer. McMahon is easily setting up a series with the PAR and I'm here for it! I can't wait until the next novel in this series comes out.

Thank you to Minotaur and Netgalley for a copy in exchange for review consideration. The opinions in this review are all my own.

Gardiner Camden is an FBI agent assigned to the Patterns and Recognition unit (PAR). He and his colleagues look into difficult cases that have thus far stymied other members of law enforcement. The PAR agents’ job is to develop theories based upon their ability to notice anomalies and pick up on obscure clues that others have missed. After they do so, they turn the matter over to a team that follows up, since members of the PAR unit do not communicate with local detectives or with members of the public.

Gardner is a savant with an eidetic memory who frequently behaves awkwardly in social situations. Much to his surprise, he is assigned to go into the field as the head of his team when a vigilante starts tracking down and slaying serial killers. The executions occur in various states and the perpetrator leaves mysterious objects behind that test the ability of Gardner and his colleagues to think outside of the box. During what will turn out to be a lengthy manhunt, Camden, Frank Roberts, Cassie Pardo, Joanne Harris, and a rookie named Richie Brancato, travel to numerous states. They interview witnesses, analyze autopsy results and other forensic evidence, conduct online searches, and dig into the past to uncover the motive for these savage crimes.

“Head Cases,” by John McMahon, is a grisly work of fiction in which we read about brutal attacks against women and are exposed to gruesome scenes in which the author describes various forms of dismemberment and mutilation. The extremely complicated plot requires a great deal of patience to navigate. Although Gardiner’s Holmesian ability to come up with obscure answers is admirable, the PAR unit’s pursuit of the murderer takes so long that, by the time we reach the finale, we are sickened and exhausted by all of the violence we have witnessed.

Wow what a rollercoaster of a book. Great suspense and really enjoyed the psychological aspect. Really enjoyed this one.

Head Cases follows a captivating group of FBI agents chasing a vigilante murderer. Our main character, Agent Gardner Camden is a puzzle-solving mastermind. His character reminded me so much of the character House from the tv series (as far as his level of genius and expertise) He definitely is a multifaceted character that I couldn’t get enough reading.

When another victim surfaces the hunt is on to find the serial killer. A killer that was assumed dead. Without giving it away- this is a smart read that was fast paced from the get-go. Absorbing and engaging thriller!! My first book by the us author and hopefully not my last:)

Thank you to NetGalley and the publisher. Head Cases follow the pattern and recognition unit (PAR) in the FBI. The unit is made up of agents who are laughed at by most people. They are given the cold cases and are kept out of the public. That changes when Agent Gardner Camden is chosen as lead on a serial killer case. Head Cases reminded me of Criminal Minds. I enjoyed seeing how the group put together clues. I do feel like it took a bit for me to become invested, but once I was interested, I couldn’t put it down.

I thought this was a good FBI procedural book. It was kinda slow moving but it does keep your attention. There’s some surprises along the way. I would be interested in seeing where this team goes.

If you like Criminal Minds or police procedural thrillers, Head Cases should be your next read!

This book follows an FBI unit as they are on a cat-and-mouse chase for a serial killer hunting, in a Dexter-esque fashion, other killers. Special Agent Gardner Camden is at the heart of this unit, and he's unique in his pattern recognition abilities, superior intelligence and lack of people skills. The book kicks off with a bang when Camden and his team discover the murder of a criminal they had previously thought to be dead, and it takes off running from there.

After the first few chapters, I couldn't put this book down- it's engaging with a fast-pace and short chapters, multiple murders and puzzles to be solved. The big bad- who calls himself 'God' and whom Camden calls 'Mad Dog'- is a worthy villain and his motives will keep you guessing. Definitely bring your brain for this one as it will get you thinking. A really satisfying thriller read. I am already looking forward to the next book in the series!

Thank you NetGalley and St Martin's Press for my earc in exchange for my honest review.