Head Cases by John McMahon is a captivating and fast-paced debut that introduces readers to an exceptional FBI unit tasked with solving the unsolvable. The story follows Gardner Camden, a brilliant yet socially awkward agent in the Patterns and Recognition (PAR) unit, a team of FBI specialists who tackle the most perplexing cold cases. When DNA links a recent murder to a long-dead serial killer, Camden and his team are thrust into a high-stakes investigation that quickly spirals into a deadly game of cat and mouse.

What sets Head Cases apart is its unique cast of characters, each with their own set of quirks and specialties. From a mathematician to a weapons expert, the diverse team works in tandem, using their collective expertise to crack the case, while Gardner’s personal blind spots add an intriguing layer of complexity to the investigation. The killer, however, is always one step ahead, leaving behind a trail of puzzles designed specifically for Gardner. As the investigation unfolds, the tension rises, and it becomes clear that the team is not just hunting down a murderer—they are also racing against time to protect their own families from the killer’s growing obsession with them.

With its sharp writing, intricate plot, and engaging ensemble cast, Head Cases keeps the reader hooked from start to finish. McMahon masterfully balances thrilling action with psychological depth, offering a story that’s as intellectually stimulating as it is suspenseful. For fans of twisty crime thrillers with a touch of genius, Head Cases is a must-read.

Head Cases feels like a perfect blend of some of the best crime and procedural TV shows. It reminded me of Scorpion, with its team of uniquely skilled misfits trying to keep their funding and avoid getting shut down. It also had the charm and wit of The Mentalist, particularly with the budding romance subplot that gave me early Jane and Lisbon vibes. And, of course, there’s a Criminal Minds feel, with a specialized team solving complex cases while navigating their own interpersonal dynamics.

This book does a great job of balancing character development with the procedural elements. We’re introduced to a team where each person has their own distinct personality, and we get just enough backstory to keep us intrigued without being overwhelmed. For readers who love longer detective series, this sets up a promising foundation. I also liked how the book immediately shows the dangers of the job and how they impact the characters' personal lives. It gives the story an emotional depth and foreshadows the kind of long-term stakes we’ll likely see in future installments. I already get the feeling that one day, a past case will come back to haunt them, which is always a great setup for a crime series.

Overall, this was a solid, engaging read. It wasn’t mind-blowing, but it felt like watching a two-hour special of my favorite crime, cat-and-mouse serial killer shows. Thanks to Macmillan Audio and NetGalley for this ALC—the narration was fantastic! The narrator did an amazing job giving each character a distinct voice, which made the story even more immersive. If this does turn into a series, I’ll definitely be keeping an eye on it.

FBI Agent Gardner Camden along with a group of quirky and sometimes outcast agent make up the Patterns and Recognition (PAR) unit. When a serial killer, long thought to already be dead, is found dead quickly followed by another serial killer, Agent Camden and PAR are brought in to try and solve the crime. After quickly finding a few clues that were left, Camden and his fellow agents race to beat the clock and the possible closure of their unit, while Camden also needs to make sure his family is kept safe. Head Cases was a heart pounding, crime focused thriller with excellent, fully fleshed out characters. Hoping Gardner and PAR will be returning for many more books to come!

I’m so upset with myself for putting this book off for so long. This was seriously so good. This is for the lovers of police procedurals and criminal minds. I felt like I was reading a book of criminal minds. The narrator did an amazing job. He had a great voice and I could tell which character was which based on how he was speaking. I need the second book immediately!!

This has nothing to do with the author, and everything to do with me. I did not feel connected to the characters or storyline. I did think some of the characters resembled some from Criminal Minds, though. I DNF’d the book mid-way.

This book sadly was not for me, but I’m many others would enjoy.

Thank you so much to publisher and author for allowing me to get an early copy of this.

*4.5 Stars On My Instagram Account*

"A serial killer was murdering serial killers."

There are many intricate moving parts to this well crafted FBI procedural audiobook expertly written by brilliant author John McMahon and perfectly performed by premier voice actor Will Damron. It's unusual when listening to a murder mystery, about a serial killer murdering serial killers, using their own methods to kill them, that I'm left with a smile at the end.

FBI Agent Gardner Camden is a crime solving analytic genius. He sees pieces coming together at a crime scene when others see a bloody gruesome death. He and his team of quirky experts, from a math prodigy to a sharp shooter, make up the secret PAR Unit (Patterns and Recognition Unit) that are called in when cases have no hope of being solved by anyone else.

When DNA at a brutal murder reveals the victim is a serial killer, who was thought to already be dead, and who Gardner has history with, his team is called in. Soon there's another murder and PAR quickly puzzles out the pattern.

What makes this more than just a procedural is the complexity of Gardner's life. As smart as he is, his mind just doesn't understand social cues, he doesn't grasp subtitles; except when protecting his adorable 7 year old daughter and his Mom, who is recognizing him less each day. He even makes sure his ex-wife, in jail for embezzling--yes he sent her there--is safe when the killer comes for his family.

The FBI wants to disband his unit, derogatorily nicknamed The Head Cases Unit, since each of them had run-ins with authority. Suspense, twists, heartfelt moments, and a bit of romance make it a no brainer that this series debut is a winner.

I received a free copy of this audiobook from Macmillan Audio via #NetGalley for a fair and honest review. All opinions are my own.

Thank you to @macmillanaudio for the ALC! Unfortunately this book wasn’t for me. I felt that taking over halfway to truly kick off the mystery and up the stakes caused the book to drag some. I found myself unengaged and at times bored. I couldn’t connect with the main character or the procedural bits. Not even the family aspect kept me engaged. Ultimately this was disappointing as I highly anticipated this book. This was not for me.

Head Cases was such a gripping audiobook! I was hesitant with another FBI/agent narrator since I feel like it's been done over and over again, but this story was unique and interesting as we follow agent Gardner Camden with the PAR Unit of the FBI. As the first book in what seems to be a new series, Gardner leads a case in which a serial killer seems to be murdering serial killers in an act of vigilante justice. With a squad consisting of "misfit" agents, McMahon takes readers on a cross-country journey trying to track a mystery killer in a cat and mouse game of revenge. I'm already looking forward to the next book in the series and would recommend this audiobook to anyone who likes detective narrated stories, psychological thrillers, and quick witted/quick-paced plot lines.

I love a good thriller, a good serial killer story, and a good look at the pscychology behind crimes--"Head Cases" has all of that. It's the story of an elite FBI unit--the Patterns and Recognition Unit--that looks into cases that seem too difficult to solve like the current murder cases that seem to be connected but no one can quite figure out the patterns.

It was a good thriller with likeable characters, though I would have wanted a little bit more insight into the characters as it was a little difficult to identify with them and keep track (that could also be because I listened to it and may have been distracted). As this is the first in a series, I do also expect more character development over the next few books.

Overall an enjoyable audiobook with room to grow in the series.

Book: Head Cases
Author: John McMahon
Format: Audiobook
Genre: Mystery, Thriller
Review Score: ⭐️⭐️⭐️1/2 (rounded up)

This was so interesting! I loved the PAR unit, their intricate thought process, and seeing how they solve cases. I used to watch Criminal Minds a lot, and this was reminiscent of that show. This is the first book in what will be a series of the PAR team, and I can’t wait for future books.

Will Damron, the narrator of the audiobook, did a great job. He made me like Agent Gardner so much more. I actually really liked every agent on the PAR team, and I hope the rest of the series features each agent in a more pronounced role.

I loved the quirks, the mysterious reasons for each member being on the team, the characters themselves, how they solved this case, the neurodivergent representation, the unconventional pieces….so much.

Thank you St. Martin’s Press and Minotaur for the ARC and Macmillan Audio for the ALC!

This novel follows FBI agent Gardner Camden as he and his team attempt to track down a killer, discovering he’s taken a Robin Hood mindset to justify becoming a serial killer of other killers or bad people. The killer plays a game of cat and mouse with Camden, making the case more personal and the stakes higher.

The high stakes of this case create lots of action packed, tension filled moments. The plot is well developed and builds off of good characterization and relationships to make you feel more invested in what happens next. This case gave me vibes of Psych’s Yin and Yang episodes!

This is a quick listen if you love cold case, serial killers, cat and mouse dynamic, or action packed plots!

This book is amazing!! It reminded me of Criminals Minds and the BAU. I cannot wait for another.

Thank you Net Galley for the ARC.

Head Cases is a thrilling and engaging audiobook that kept me hooked from start to finish. The concept of the PAR unit and their unique approach to solving cases was fascinating, and I enjoyed following along as they pieced together the clues left by the killer. The character development was well-done, and I found myself rooting for Gardner and his team throughout the story.

While I did struggle with the narrator at times and found some parts of the story to be a bit confusing, overall Head Cases is a well-crafted mystery with plenty of twists and turns to keep listeners guessing. The tension builds steadily throughout the book, leading to a satisfying conclusion that left me eager for more.

I would recommend Head Cases to fans of crime thrillers and intricate puzzle-solving plots. John McMahon has created a compelling world with interesting characters that I hope to see more of in future installments. Thank you to NetGalley for providing me with the opportunity to listen to and review this gripping audiobook. 4 stars!

I'm always happy to find a new a mystery/thriller series to dive into, especially when there's a serial killer aspect to it. So listening to this one made me very happy - I just wish there weren't a wait for the next one.
While it feels like a bit of a mashup of some of my other favorites, it's actually its own unique thing - the story of a newish FBI Unit (PAR: Patterns And Recognition) which was formed of experts in their field, each of whom has also previously screwed up on the job somehow and been banished to the Jacksonville FL office as an experimental team (think the Island of Misfit Agents) and their future as a unit is uncertain. Then along comes a new case: someone is killing serial killers. And while it mostly feels like good riddance to bad rubbish, it still needs to be investigated, and the first victim discovered has ties to one of the members of the team, Gardner Camden. Camden is a socially awkward agent with a photographic memory and a strong moral code that's led to issues in both his work life and his personal life. Because of his ties to this case, he's tagged to be lead investigator.
I enjoyed all of this - I liked the quirky members of the team, I liked the pacing, I liked the writing - very atmospheric in a variety of settings. I can highly recommend the audiobook, which was wonderfully narrated by Will Damron. And I'll be trying John McMahon's previous books while I wait for the next book in this series.
Thanks to Netgalley, St. Martin's Press, and Macmillan Audio for providing copies for an unbiased review.

At the start, I felt like I could really get into this book. It felt like any crime drama with a quirky, smart lead detective. We have a special team in the FBI that will take on cold cases because they view things just a bit differently than other agents. Enough that they might be able to catch onto a missed pattern or something subtle that could easily be overlooked. Intriguing, right?
But then I just got bored. I was listening to the audiobok and I found myself losing interest and not really paying attention to what was happening anymore. I wasn't invested in any of the characters and I had a really hard time trying to keep names straight. Even by the end, I wasn't just who was who. I even mistook his partner for his daughter. Yikes.
This is the start of a series. And by the way that it ended, I questioned how I felt about reading on to the next book. Something about how the setup for continuation had my interest peaked and maybe, must maybe, it could redeem itself for book 2.

To say I enjoyed FBI Agent Gardner Camden is an understatement. I loved his eccentricities, and he has quite a few of those. But his intelligence and his passion are truly fun to watch…uh…I mean read about! (This needs to be a TV series!) I love a flawed character!

Along with Gardner, the Patterns and Recognition unit of the FBI consists of a mathematician, a weapons expert, a computer analyst, and their leader, a career agent. Each of them must use every skill they have to solve the riddle of the killer’s identity. And what a riddle this story is! I enjoyed the chase across state lines and all the deductions. The author truly created an intricate pursuit of a killer!

The narrator, Will Damron was magnetic. Honestly, I am going to have to be on the look out for more books by this guy!!

Need a good hunt for a killer…THIS IS IT! Grab your copy today.

I received this novel from the publisher for a honest review.

This was an excellent book. I had a great time getting to know the characters and watching their relationships change. They were an intelligent and interesting group. The mystery was also interesting with little intricacies. I loved how the MC put it together and the reader was privy to his thought process. I did not have this one figured out early on and it was nice to watch it all unfold. It took a moment in the beginning to get used to the writing because the MC is very unique so it felt strange to be in his head, but once I settled in it was a fun ride.

This was my first book by McMahon and I'm so glad I jumped on this series with the first book. I can't wait to see where the team goes from here. I'm already looking forward to the next book in the series.

I was fortunate to have the ebook and the audiobook for this one. The audio was narrated by Will Damron and he did an excellent job. He really brought the characters to life for me and I hope he continues to narrate the series.

Thank you to NetGalley and the publisher for the ALC of Head Cases by John McMahon. This gripping thriller is packed with tension, dark secrets, and an unpredictable mystery that kept me engaged. McMahon’s writing is sharp and immersive, pulling me into the mind of the protagonist as he navigates a case filled with twists and moral dilemmas. The psychological depth adds layers to the story, though some parts felt slightly rushed or underdeveloped. One flaw that stood out was the pacing—while the book starts strong and keeps the tension high, certain key revelations felt hurried, making it difficult to fully absorb the emotional weight of the twists. A bit more time spent unpacking the consequences of these moments could have made them more impactful. Despite this, the story remains compelling, and Head Cases will appeal to fans of dark, thought-provoking crime fiction.

If you like Criminal Minds, Benedict Cumberbatch's Sherlock, this book is for you! Someone is gruesomely killing bad people. Is it a vigilante or are they doing it for some other twisted reason. The PAR team is run by Camden an analytical genius who loves solving puzzles. This is interesting, I love the team and can't wait to see what they'll do next. Will Damron was a great narrator for this book.

I almost DNFed this because it started out feeling very "Sheldon Cooper goes to the FBI", but I stuck it out and it did get better. I enjoyed this mystery, but not sure if I will continue with the series. I saw another review that said this felt like a novelization of an FBI procedural show, and that felt right to me--entertaining, enjoyable, but in this case not particularly memorable. However, given that this was a first in a series, it's possible the characterization might be richer in future installments. In any case, if you are looking for something to scratch the same itch as those shows, this may be just what you're looking for.