Head Cases by John McMahon is a gritty, hard-hitting crime thriller that dives deep into the complexities of mental illness, criminal justice, and the underworld of law enforcement. The novel follows the journey of Detective Sam “Ace” Acevedo, a tough and seasoned investigator in Atlanta, who is called to investigate a series of brutal murders that seem to have connections to a local psychiatric hospital. As Ace delves into the case, he uncovers a labyrinth of lies, corruption, and hidden agendas—leading him into dangerous territory where his own moral compass is tested.

McMahon does an excellent job creating a dark, atmospheric setting for the novel. The gritty, urban backdrop of Atlanta feels alive with tension, from the dingy hospital wards to the seedy underbelly of the criminal world. This sense of place plays a key role in setting the tone for the entire book, and it draws you into Ace’s increasingly complicated investigation.

The protagonist, Ace, is a compelling, multi-dimensional character. He’s haunted by his past and grappling with his own demons, which adds depth to his character and makes him both relatable and flawed. His moral ambiguity and personal struggles make him an engaging figure to follow, especially as he navigates the complex and morally gray world of crime and justice. His determination to uncover the truth, even when it puts him in danger, adds a layer of intensity to the story.

The writing is sharp and direct, with McMahon effectively building suspense through short, punchy chapters and alternating perspectives. The narrative unfolds at a brisk pace, constantly throwing new twists and revelations that keep you on your toes. As the investigation progresses, McMahon layers in plenty of red herrings, keeping readers guessing until the very end. The twists are clever without feeling contrived, and the final reveal ties everything together in a satisfying, though intense, way.

What sets Head Cases apart from other crime thrillers is its exploration of mental health and the ethical questions surrounding the treatment of those deemed “insane.” McMahon doesn’t shy away from tackling the darker aspects of the medical system, as well as the societal stigma associated with mental illness. This adds an emotional depth to the story that makes it more than just a typical detective novel.

In conclusion, Head Cases is a thrilling, emotionally complex novel that will appeal to fans of gritty crime fiction with a moral edge. McMahon delivers a fast-paced, suspenseful plot filled with rich character development and a haunting exploration of the human psyche. If you’re into dark mysteries that combine crime, psychology, and suspense, this is a book you’ll want to pick up.

I really liked this one and am excited to see that more titles are coming! McMahon has done a really solid job crafting a team that is compelling and human, full of "misfits" who are fascinating in their quirks and back stories. The concept of a team of behavioral analysts is certainly not a new one, but despite this being well-trod ground, I found the execution here to feel engaging and fresh and it held my attention from start to finish. It's a fast-moving story that hums along, and the characters add a depth to the experience that I enjoyed. I read and listened to this one, and enjoyed both experiences and cannot wait to see where things go next!

I'm stoked that Head Cases is the first book in a new series. I was hooked from the very first page and flew through the story from beginning to end.

The characters were great, it read like a criminal minds episode following around the PAR (

Patterns and Recognition) Unit. The main character is FBI Agent Gardner Camden and he's an awesome MC, he's intelligent and interesting. I love the dynamic he and Cassie, his partner have, she brings the much needed humor.

An incredible thriller, John McMahon knocked it out of the park, it was so well written and kept me on my toes the entire time. The murderer was playing games with the team mostly with Gardner which was a really cool aspect as the team got closer to solving the case.


I absolutely loved it.


4.5 Stars


Thank you to St.Martin's Press, Minotaur Books and Netgalley for this ARC!

I love a good FBI procedural book and this one did not disappoint!! I loved how the killer in this book tracked down other killers and how he killed them! The Chace to get him was so good!! Can't wait tobread more of this new series!

Bestselling author John McMahon returns following his popular P.T. Marsh novels with a fascinating new series, PAR #1 HEAD CASES—a group of misfits, brilliant freaks (known by some), FBI agents that leave their desks and hit the road to track down a serial killer who murders serial killers— seeking his own justice in this dazzling and compelling new crime thriller debut series.

About...

FBI Agent Gardner Camden is an analytical genius and enjoys solving puzzles. He also has a blind spot on the human side of investigations, which often includes his beloved seven-year-old daughter Camila, who lives in Miami while he works in Jacksonville.

Gardner and his squad of brilliantly talented yet quirky agents make up the Patterns and Recognition (PAR) unit. Each member possesses unique skills that make them the hidden secret of the FBI. They tackle cases no one else can solve, making them a team to watch and a group of characters you'll be eager to learn more about.


THE ACE: Specializing in puzzles, patterns, and decoding enigmas.
THE BOSS: Old School FBI—plays his card close to the vest.
THE ANALYST: Creates crime scenes in her head.
THE SHOOTER: A born and raised hunter.
THE ROOKIE: A prodigy just out of the academy.


The team is assigned to a case when DNA links a murder victim to a serial killer who was long presumed dead. Ross Tignon, a man he had hunted years ago, stopped because he turned up dead.

Seven years earlier, he was the primary suspect in Florida for three women's murders, and then a fire broke out in his home. If this man had been killed yesterday in Texas, whose body was in the Florida fire?

A second victim follows, creating a pattern, and the murderer starts leaving a trail of sinister clues and riddles for Gardner.

They hit the road following the killer with Gardner, and each of them uses every skill possible to solve this complex mystery. Their determination to protect themselves, the team, and their family, even when the killer seems to be one step ahead.

As the case unfolds, Gardner's professional detachment is tested. He's a seasoned professional tasked with profiling crimes that others can't solve. But this case is different. It's personal. With the killer seemingly always one step ahead, Gardner's worry for his mother and daughter's safety grows. He must find a way to warn them before it's too late, and you'll feel the intensity of his struggle.

Gardner's mom relocated to Texas from South Carolina. She was a psychiatrist for twenty years before she retired and moved west; she was on retainer with the Charleston Police Department and consulted on numerous investigations. But now she is in a home. Garnder sends money to his mom and daughter even though he can't always be around.

Two people could make Gardner's heart sink: His mother and his seven-and-a-half-year-old daughter, who lives with her grandmother in Miami. He visits on the weekends. He must keep them safe before the serial killer gets to them.

The dangerous game of cat-and-mouse begins with a sinister killer with an agenda and a revenge plot!

My thoughts...

HEAD CASES is:
Brilliant.
Original.
Electrifying.
Clever.
Edgy.
Enigmatic
Action-packed.
Suspenseful.
Mysterious.
Cat-and-Mouse Twisty.
A STUNNER!

Move over: My new favorite FBI team (PAR) and crime series are in town—prime for the big screen. I love these characters. Bring on #2! I can't wait to see what's next for the PAR team, and I'm sure fans will share my excitement for the next installment.

🎬 I'm thrilled to hear that this series has been optioned for HBO Max. The thought of seeing these characters and their thrilling adventures on screen is truly exciting.

This is the author's fourth book, and as with the past series (I also enjoyed and need to catch up with the last one in the P.T. Marsh series), a well-written procedural, gripping plot, razor-sharp, witty, intelligent, and fast-paced—keeping you on the edge of your seat. Like Michae Connelly's Bosch, Gardner is a fantastic character who loves and protects his family.

Fans, get ready for more! Another book is on the way, and you'll be on the edge of your seat, eagerly anticipating the next thrilling adventure of this fun group in Miami! I love books set in my backyard.

Audiobook...

I read the book and listened to the audiobook narrated by one of my all-time favorites, Will Damron. The award-winning performance captured these quirky, intelligent FBI characters and secondary character voices—impressive — elevating the novel and making this a captivating listening experience. The characters came alive on the page, and I became hooked from beginning to end. His performance was superb. I highly recommend the audiobook and this series. I hope he will be narrating the next in the series!

Recs...

This book is a must-read for fans of the author and those who enjoy Criminal Minds, The Mentalist (my favorite- I love Patrick Jane), and Karin Slaughter's Will Trent series. It's a perfect blend of the best elements from all these works.

Thanks to Minotaur Books, St. Martin's Press, and Macmillan Audio for an ALC and ARC via NetGalley in exchange for an honest opinion.

blog review posted @
JudithDCollins.com
@JudithDCollins | #JDCMustReadBooks
Pub Date: Jan 28, 2025
My Rating: 5 Stars
Jan 2025 Must-Read Books
Jan Newsletter

This book had me hooked from the start. What a great start to this new series. We are introduced to a new group of FBI agents, Patterns and Recognition Unit based in Jacksonville. The team led by Special Agent Gardner Camden, who has an eidetic memory and is socially awkward, usually deal with cold cases.. However, due to Camden's past with the late serial killer, Ross Tignon, who has been found murdered in a most brutal manner, the team is put in the field. The death of another serial killer, just a day after being out on parole for a day amps up the investigation. This killer begins to taunt Camden, calls him, threatens his family, leaves cryptic clues on the bodies, wants to be referred to as "God", instead Camden calls him "Mad Dog"

What follows is an exciting game of cat and mouse. Camden is aided by Cassie Pardo, a wiz with numbers, Richie Brancato, with a sealed file??, The Shooter", a weapons expert and Frank Roberts, who is the official head of the team. This killer has somehow gotten ahold of sensitive information, could he be an FBI agent? The author keeps us on the edge of our seats with some twists and turns as we reach a satisfying conclusion.

If you are a fan of shows like Criminal Minds, Numbers (an oldie) you will enjoy this book. I am eagerly waiting for next installment.

Thank you to NetGalley and the publisher, Minotaur Books, for an ARC. The review is my own.

HEAD CASES was an entertaining, very fast paced read about a band of FBI misfits hunting a killer of serial killers. I felt like I was following the clues and cracking the puzzles alongside Agent Camden. I do wish there had been some element of humor or sarcasm written into his character, it felt like there were perfect times for some dark comedic relief that were missed. But overall a really refreshing, fun, nerdy ride!

Recommend for fans of Andy Weir or Blake Crouch.

I would give this book 500 stars if I could. It was SO SO GOOD

Special Agent Gardner Camden loves puzzles. He is one of four of the PAR team in the FBI, an analytical bunch who each have their own special talents for taking down bad guys. When a murder occurs in Florida of someone who is already supposed to be dead, Camden is brought in to lead the case since he was chasing this particular man years prior and thought he was indeed, dead.

This case turns into a serial killer who is targeting prior serial killers (a little ala Dexter...). I had to put this book down to do something IRL and honestly all I kept thinking about was returning to it for the conclusion. It's a little bit like the show Numbers, with a lot of math and puzzle solving. The main character self identifies as odd and he has learned to embrace the label.

I am delighted there will be another book in this series for sure, and I hope there will be many more after that. I think this author has a great knack for painting the underdog a hero and I cannot wait to see with what he comes up with next.

I didn't mind this much but this book is quite graphic in some of the crime scene descriptions, so reader beware.

I highly recommend this book for anyone a fan of police procedurals or crime dramas. You won't be sorry.

My thanks to Netgalley and Minotaur/St. Martin's Press for this ARC. I am going to buy this book.

With nods to Criminal Minds, a group of quirky FBI agents in a specially created unit find themselves unexpectedly in the field when someone starts serial killing serial killers. I enjoyed the main character’s (Gardner Camden) attempts to understand himself as he tries to unravel the puzzles the killer leaves him. This was a fast-paced rollercoaster thriller, and the first book in a really long time that I could not get out of my mind when I was meant to be doing other things. I can’t wait for the next in the series, and hope to get to learn more about the lives and motivations of the other agents in the group he works with as the next books come.

Thank you to St. Martin’s Press, Minotaur Books, Netgalley, and the author for early access to this thoroughly engrossing thriller.

Misfit FBI agents are pulled into a game of cat and mouse

The FBI has created a unit known as PAR (Patterns and Recognition) which is brought onto cases when other law enforcement groups have hit an impasse. It is staffed by four individuals who have unique skill sets that facilitate the creation of new theories and solutions to crimes based on patterns and peculiarities that others miss. The agents have something else in common, however; they have all had a colossal screw up earlier in their career which landed them in this band of talented misfits nicknamed the Head Cases: Gardner Camden, who has an exceptional mind that works differently than most peoples' do, resulting in awkward social interactions; Cassie Pardo whose analytic skills are mathematical in nature; Joanne "Shooter" Harris, a skilled shooter who knows everything there is to know about weapons of all kinds as well as possessing extensive hunting experience; and the rookie Richie Brancato, a computer expert who had graduated at the top of his FBI class but has inexplicably asked to join this less-than-well-regarded unit. They are led by Frank Roberts, old school, always well put together and inclined to play his cards close to the chest. They are summoned to a murder scene where the victim is a serial killer that had supposedly died in a fire years earlier. Camden was lead on that old case, and it bothers him greatly that he got something that wrong. When another dead body pops up it looks like the PAR team has a real problem....there is a serial killer on the loose who is targeting other serial killers and has information that seemingly only someone in law enforcement would have. To make matters worse, the killer is determined to pull Camden and the others into his game, and no one in the teams' life is immune from becoming a target if that is what it takes to bring them on board. The clock is ticking....can the team identify who is behind the new spate of killing without them and their loved ones becoming victims too?
The story unfolds from the point of view of Camden, a neurodivergent protagonist who finds relationships (even with his seven year old daughter) a daily challenge, and whose greatest talents are entwined with his biggest flaws. His background, from the psychiatriist mother who raised him to cherish his differentness to his late partner whose daughter he married, unspools alongside the story, as do the political games being played at FBI headquarters which may end up with the dissolution of PAR. At times the amount of background information being shared did impact the pace at which the plot moved along, but not so much so that I didn't enjoy the read. The mystery at the heart of this thriller presents an interesting moral question...how hard should the authorities really work to catch a killer who is removing from society some of the worst criminals there are? It is an engrossing game of cat and mouse, where no one can be completely trusted and the person in charge of the case quickly starts doubting his fitness to lead. Readers who enjoy Jussi Adler-Olsen's Department Q novels, the Memory Man series by David Baldacci and Mark Haddon's The Curious Incident of the Dog in the Night-TIme should add this book to their TBR list. It is the start of a proposed new series, and there is a great deal of background to mine amidst this quirky band of agents who have fallen from grace. My thanks to NetGalley and St. Martin's Press/Minotaur Books for allowing me early access to Head Cases in exchange for my honest review.

Thanks to the publisher and Netgalley for this eARC.

John McMahon's "Head Cases" is a psychological thriller that burrows deep beneath the surface, exploring the fragile boundaries between sanity and madness. McMahon masterfully crafts a narrative that twists and turns like a labyrinthine maze, leaving the reader constantly questioning their own perceptions of reality.

The story unfolds through the interconnected perspectives of a diverse cast of characters, each grappling with their own unique brand of mental anguish. From a struggling artist haunted by visions of a long-dead lover to a detective investigating a series of bizarre and inexplicable murders, McMahon delves into the depths of the human psyche with unflinching honesty.

"Head Cases" is a testament to McMahon's masterful prose. His writing is poetic and razor-sharp, capturing the nuances of human emotion with a raw and unflinching intensity.

The atmosphere the author creates is thick with dread and suspense, building to a crescendo of shocking revelations that will leave you breathless.

However:
* The nonlinear narrative can be disorienting. The fragmented perspectives and shifting timelines may require close attention from readers and can be challenging to follow at times.

* The ending may feel ambiguous or unsatisfying. Some readers might crave a more definitive resolution to the mysteries presented throughout the novel.

"Head Cases" is a captivating and unsettling journey into the darkest corners of the human mind. It's a novel that will stay with you long after you've finished reading, prompting you to question your own perceptions of reality and the fragility of the human psyche.

HEAD CASES (PAR Unit #1) by John McMahon is an engaging and exciting first book in a new series featuring a group of extremely talented and specialized FBI agents, who while brilliant in their specific areas, have had a serious misstep in their careers and are now grouped together for a last chance to keep their jobs. While the PAR (Patterns and Recognition) unit is quirky, the book’s crime plot is gripping, gritty and graphic as they chase a serial killer of serial killers.

FBI Agent Gardner Camden is an analytical genius with an eidetic memory who loves puzzles but is extremely socially awkward. The PAR unit is not deployed to the field but is used when all others have failed to solve a case by analyzing data from their office and finding that missing piece that helps solve the case.

But this case is different. The DNA of a murder victim has come back as a match to a serial killer who was presumed dead. Gardner’s supervisor and the head of the FBI have chosen him to lead this hunt in the field. While the Gardner and the team look forward to the field work, they also realize that if this case is not solved, the recriminations will blow back on them and they could be reassigned or terminated.

The killer has personal information on Gardner that could only come from his FBI file as he taunts and threatens him and his family after another kill. Can Gardner and his unit stop this killer before his endgame and final disappearance?

This is an exciting serial killer crime thriller that kept me reading from page one to the end. Gardner is such a great protagonist, and the author brings him to life as a fully developed and believable character. While not stated in the story, you realize he is somewhere on the spectrum, but his mother has taught him how to deal with his special intellect and social awkwardness from childhood. All his other teammates are brilliant and interesting in their own quirkiness and specialties and will probably be more in the limelight in future books.

The crime thriller plot in this story is perfectly paced with a God complex serial killer and the step-by-step hunt to capture him. Some of the surprises along the way come from more than just the antagonist and Gardner must make decisions that not only affect him, but his whole unit. There are graphic descriptions of blood and body parts throughout, but it is a serial killer thriller and to be expected.

I highly recommend this crime thriller police procedural with great new characters that I am looking forward to following in future books.

Really enjoyed the first in what I hope will be many in the new PAR series -- even more than I expected. Police procedurals tend to be a bit hit or miss for me, but this one took hold. The pacing was fast and strong, the cast of characters was interesting and engaging without feeling forced, and the plot had a nice balance of intrigue and action for me. The "serial killer hunting serial killers" was a great hook, and it was executed well. Will be looking forward to book #2!

This is an exciting new series that I am happy to delve into. A similar vibe to the show criminal minds and the characters were shining stars. The chemistry works and for a series to continue and pull interest, this is a key component for me to want to grab book number two.

Thank you NetGalley for the ARC, in exchange for an honest review.

Police procedurals were never like this one – very thrilling and enigmatic. Gardner Camden leads the group, the Patterns and Recognition unit of the FBI. When a case cannot be solved, this is who is called. His group is almost as quirky as he is, with specific skills and interesting back stories. But Gardner, with numerical insights into patterns, an ability to connect puzzling pieces and a memory for the smallest detail is the neurodivergent star.

This case involves a serial murderer who is killing other serial murderers. Or is that really what is happening? Has Gardner met his match? Meanwhile the team and Gardner may be endangered or may even be compromised as they hopscotch across the country. The clock is ticking as more murders occur.

Exciting and highly recommended. Desperate for a sequel! Thanks to Netgalley and the publisher for providing this title.

📚 PRE-PUBLICATION BOOK REVIEW 📚

Head Cases By John McMahon
Publication Date: January 28, 2025
Publisher: St. Martin's Press | Minotaur Books

📚MY RATING: ⭐⭐⭐⭐✨
(Rounded Up To 5⭐)

Thank you to NetGalley and St. Martin's Press | Minotaur Books for this #gifted advanced e-copy of the book in exchange for my honest review!

📚MY REVIEW:

The FBI is chasing a serial killer who's killing serial killers. If you're a fan of crime fiction like me, I know you've just added this book to your TBR List -- simply from that one sentence!

Head Cases was a phenomenally gripping and fast-paced thriller that had my attention from the start! As a huge fan of crime fiction and police procedurals, I couldn't get enough of this FBI team as they tried to track down the unhinged serial killer who always seemed to be one step ahead of them... And who always seemed to know exactly where they'd be and what they'd do next.

Agent Gardner Camden (coolest name ever!) is part of the FBI's PAR Team, a brainy bunch of agents who seem to have become the FBI's pariahs. They all either made a huge misstep on a past case or pissed off the wrong boss. Camden is tasked with leading the team as they try to find the killer and solve the case, which takes them to current murder scenes and unearths clues from their past cases too. I loved all the characters on the team, and McMahon did such a fantastic job of describing each character's quirks in ways that made them not just likeable, but endearing to me. The serial killer was creepy and unhinged AF, and the way he toyed with Agent Camden and the rest of the team was absolutely chilling.

This was one of those crime-fighting and case-solving reads that puts together pieces of the puzzle in a way that feels like you're figuring it all out in real time right alongside the agents. I loved the intelligent writing and dialogue in this one, and the heart-pounding suspense in these pages kept me on the edge of my seat. I also LOVED the inclusion of the infamous Murder By The Book bookstore in Houston!

If you're a fan of TV shows like Criminal Minds, CSI, or FBI, you're going to love this one! I think fans of crime fiction and police procedurals are going to be mega-fans of this one. I'm so excited to know that the second book of the series comes out in early 2026 too!! This first intro into McMahon's books has me clamoring to dig into his backlist (and I SO appreciate that he listed the order I should read them in this book's acknowledgements)!

#HeadCases #JohnMcMahon #MinotaurBooks #StMartinsPress #NetGalley #NetGalleyReviews #ARC #thrilleraddict #thrillerlover #crimefiction #policeprocedurals #booklover #bookreviews #bookrecs #bookrecommendations

Thank you NetGalley and Macmillan Publishers for the early release of Head Cases. I unfortunately did not mesh well with this book. As a fan of crime thrillers, true crime, mysteries, and thrillers I thought that this book would be the perfect read for me. I did not connect to the characters or the plot and felt like a lot was going on and nothing at the same time. Just because this was not for me does not mean it won't be for you so I always say reading is so subjective but this was a total miss for me.

Wow! This was crazy fast paced. I felt like I was watching an episode of Law and Order SVU. Things did slow a little in the second half of the book but it was welcomed. I loved the premise at the beginning but I felt like as things got revealed, it got a little less interesting to me. I wish we got a little more about Gardner’s daughter and wife. I also need more info on Richie. He seemed way too interesting for the role he played in this. I also didn’t love the ending getting wrapped up so nicely with everything slotting into place. Overall it was still fantastic and the title on Goodreads seems to indicate it will be a series so I’m excited to see if this continues.

Many thanks to NetGalley, Minotaur Books, and Macmillan Audio for gifting me both a digital and audio ARC of this wonderful series debut by John McMahon, with the audiobook perfectly narrated by Will Damron. All opinions expressed in this review are my own – 5 stars!

The Patterns and Recognition (PAR) unit of the FBI is a team of five brilliant but misfit agents tasked with solving cold cases. Gardner Camden may have social issues, but he’s got an amazing analytical brain that excels in puzzles and codes. Work is a priority for him, along with visits to his young daughter and elderly mother. When a serial killer from one of Gardner’s solved cases, who has been presumed dead for over a decade, is found murdered, the hunt begins to find the killer who is murdering serial killers. Gardner and his team track him across the country, hoping they can solve the riddles before it’s too late.

This was such a fabulous book and audiobook! Think Slow Horses (which I also love), a group of intelligence agents who all made mistakes, but come together as a strong team. It also reminded me a bit of Mind Hunters, and I loved the peek into the mind of a serial killer and those who hunt for them. But the characters were where this book really shines – I loved all of them, but especially Gardner. They felt real, I felt for them, and I can’t wait for more books featuring this team. Highly recommended!

Thank you to NetGalley and Minotaur Books for this eARC.

This is a review of the type I did not expect to have to write about this book. It was the most excited I’d been to receive an ARC copy because the description COULD NOT have been more up my alley. Unfortunately, I ended up with the saddest of all acronyms, a big fat DNF.

A 3000 foot view of the plot sounds like the BEST: a group of quirky FBI agents are hunting down a serial killer using their unique skill sets to catch the criminal.

How the heck do I not like this book? I loved Mind Hunter, True Detective, British crime procedurals, Sherlock, Zodiac, In Cold Blood, you name it. The problem for me came from the characters as well as the plot.

On the plot side, in the pages I read I never felt invested in the story or the case they are pursuing. This type of book should make you feel scared or nervous because of the central tension of the book. That did not happen.

Additionally, I had no connection to the characters and found they took away from the story rather than be additive. The characters are the reason I stopped reading as I found their bickering and general behavior annoying.

I do hope others give this book a try and please let me know if the book gets better after the 1/4 waypoint and I need to keep reading.