
Member Reviews

I really enjoyed the narration in this book.
I don't usually love police procedurals, but this had more of a feel of a full TV that I would follow. It has the great makings to be a series.
You really felt connected to the characters and the FBI agent that was investigating the case.

I loved this book! it was clever, it was dark and highly addictive. And come on serial killers, it had me there to be fair!! I really do hope this is the start of a new series, I want more of these characters, they were so interesting and have so much more to tell us .
The Patterns and Recognition team at the FBI are hunting a killer, a killer who is killing serial killers, it is pretty graphic at times, as you would expect from this storyline. The team are all super intelligent and I loved every bit of it. Getting inside the killers head through the team putting all the puzzle pieces together was very satisfying
The narrator, Will Damron was fantastic as always. He always brings the story to life.
Thanks so much to Macmillan Audio for my early copy of the audiobook to listen to . Out on January 28th, a must read for crime enthusiasts.

(4.25 stars)
Head Cases is the derogatory nickname other FBI folks give the members of a special unit called PAR: Patterns And Recognition. They are people who have messed up in some way in other FBI posts but they each are brilliant in their own way and seem to work really well together, usually working on cold cases.
This time, though, they are called in for a “hot” case. They are assigned to find a serial killer who is out there killing other serial killers! Gardner Camden leads the team for the first time, and he is grappling with this responsibility in addition to working the case. I loved his character; we get to know him professionally and personally. His love for his young daughter was palpable. The other members of the team were written as individuals so I had no trouble keeping track of who was who.
The mystery is a complex one and I loved guessing what was going to happen next and what the various clues might mean. The audiobook kept me and my husband entertained on a long road trip. The narrator did a fabulous job with all the voices. I’m going to look for more books narrated by Will Damron!
I sure hope there are going to be more books featuring these characters. The ending certainly hinted at it. In the meantime, I’m going to try to read his earlier books.
Thank you to Macmillan Audio and NetGalley for the opportunity to listen to an advance copy of this audiobook and St. Martin’s Press and NetGalley for the opportunity to read an advance reader copy of this book. All opinions are my own.

Real talk, I have severe insomnia (ugh, fun times), and this book was totally my overnight BFF. I binged it hard in one sitting, and let me just say, it was a wild ride. Think puzzles, FBI drama, and a whole lot of mind games that kept me turning pages like my life depended on it.
The characters? Oh, they were quirky for sure, and I low-key loved the whole misfit team vibe. The stakes felt real, like the team genuinely couldn’t afford to mess up. Also, the lead agent, is a brilliant mess—just the kind of character I love. His mind works in a way that made me want to keep reading more and more to see how he'd piece things together. The clues and riddles kept me on my toes, wondering what would happen next.
But, of course, not gonna lie, some parts had me squinting like, “Wait, what?” but overall, the twists were solid, and the story kept me hooked. It felt like an intense mix of smarts and chaos, and honestly, I was here for it.
This hit differently, maybe because I was so in the mood for a binge-worthy escape. If you're into thrillers with brainy, flawed characters and just a sprinkle of dark justice, give this one a go.
Big thanks to NetGalley for the ARC in exchange for my honest opinion! 🌟🌟🌟🌟

"Head Cases" is an exhilarating debut novel that follows a team of FBI agents, led by Gardner Camden, as they pursue a serial killer determined to impose his own brand of justice. With the team on the brink of disbandment, Camden and his colleagues must decipher a trail of cryptic riddles and clues left by the killer, racing against time to prevent further victims. The novel delves into themes of justice, vengeance, and the complexities of morality as the team faces an increasingly twisted and personal plot.
From the start, I was completely hooked, and it was hard to believe this was a debut. The author’s ability to blend suspense with intricate character development made the story even more compelling. Gardner Camden, the protagonist, is a well-rounded character—intelligent, complex, and haunted by personal struggles that add significant depth to the narrative.
One of the most striking aspects of the book is its realistic portrayal of an ongoing investigation. The meticulous attention to detail allows the reader to feel as if they’re part of the case. Every clue, every twist, contributes to the sense that the serial killer is always one step ahead, but the team's intelligence and determination keep them on track toward solving the mystery.
Overall, "Head Cases" is a fast-paced, thrilling read that skillfully balances suspense with emotional depth. I’m eager to see what the author has in store for future books, as this debut shows immense promise.

Thank you Macmillan Audio for the gifted ALC!
4.5 stars rounded up.
This book was a lot of fun, and I am super excited that it's the start of the series. I'm keeping my fingers crossed that each book is told from a different perspective for each member of the PAR team.
If you are a fan of Dr. Spencer Reid and Criminal Minds, I can guarantee you will enjoy this book too. The whole book reads like an episode told from Reid's perspective.
Highly recommend this one and I can't wait to see where the series goes next. Head Cases pub date is January 28.

I haven’t read a good police procedural in a while, so this was a refreshing one to read/listen to. I think eidetic memory is so fascinating, so I loved that the MMC had that. And the whole “PAR” team, made up of “quirky” agents was also fun. (I feel like that can be overdone, but as it’s been a while since I’ve read that, it felt fresh again to me.)
The case and plot of the story was interesting, and what I really like about crime novels and police procedurals is that it keeps me guessing. Which this one did just that. This one looks like it might be the start of a new series, so I will definitely be returning to this if a second book comes out!
𝘼 𝙣𝙤𝙩𝙚 𝙤𝙣 𝙩𝙝𝙚 𝙣𝙖𝙧𝙧𝙖𝙩𝙞𝙤𝙣: I really liked the narrator choice for this book. I can’t describe how exactly but he sounded like the brainy, anti-social character I’d picture the MMC to be.

3.5 stars
Gardner Camden is an FBI agent with the Patterns and Recognitions Unit (PAR) located in St. Augustine, Florida. Most agents in the PAR have two characteristics: they made a mistake and were subsequently transferred to the PAR; and they're brainiacs with unique abilities, like eidetic memory, math expertise, etc. Up until now, the PAR agents have been confined to office work, studying the evidence and files from unsolved cases, to look for new clues.
Camden, who's always been socially awkward, observes: "Riddles. Those are my specialty. That is, when I am not studying patterns. Or decoding enigmas. Some might say that solving puzzles is all I'm good for. That leaving my desk in the Jacksonville office of the FBI to interact with real people is not the best use of my time or talent. And I would agree with them."
Now, however, the PAR investigators have been sent to Texas to view a body. Camden recognizes the murdered man as serial killer Ross Tignon. Camden's shocked, and observes 'Tignon is a man I had hunted years ago. I had only stopped hunting him because he supposedly died in a house fire six years ago.' At that time, Tignon's incinerated body was identified by two molars, and the current corpse is missing two molars. Tignon apparently yanked out his teeth to fool the authorities. In addition to missing teeth, Tignon's body has been defaced by the killer, who cut Tignon open and carved the numbers 5 and 0 into his torso. In addition, it's later discovered the murderer left a clue INSIDE the body as well.
A few hours after viewing Tignon, the PAR agents are re-routed to New Mexico to observe another body. This victim is Barry Fisher, a serial killer who was JUST paroled for 'old age' after serving 31 years in the penitentiary. Fisher's body is terribly mutilated, with his organs excised and placed in plastic bags in the refrigerator and freezer. As is the case with Tignon, the murderer also left a clue inside a body part.
The PAR concludes A SERIAL KILLER IS TARGETING SERIAL KILLERS.
Camden is assigned to lead this multi-case investigation, a first for him at the PAR. Before long, Gardner starts to get phone calls from the killer, who says to call him God. The PAR agents, however, elect to call the murderer Mad Dog, and Mad Dog's conversation shows he has inside information about the investigation. The murderer must have a source in the FBI, and Camden takes steps to expose the mole while proceeding with the inquiries.
Mad Dog's phone calls, and the clues he leaves behind, demonstrate that he thinks of himself as a partner who's aiding the PAR. When Mad Dog is disabused of this notion, he makes threats.....and takes steps to carry them out.
As the inquiries proceed, several possible suspects are identified, the current murders are linked to past homicides, and the PAR agents must use all their skills to solve the cases.
The novel is a page-turner, with plenty of action. My major criticism is that the brilliant PAR investigators sometimes miss information they should winkle out right away. Author John McMahon probably uses this technique to prolong the suspense, but it's not credible (to me) In any case, this is a good thriller, recommended to fans of the genre.
I listened to the audiobook, narrated by Will Damron, who does an excellent job.
Thanks to Netgalley, John McMahon, and Macmillan Audio for a copy of the book.

Head Cases by @johnmcmahonbooks is a thrill seeking 5 star ⭐️⭐️⭐️⭐️⭐️ audiobook. Thank you @johnmcmahonbooks and @netgalley for this ARC. In this read, Garner Camden is a walking analytical brain in the elite FBI group of problem solving agents specializing in codes, puzzles and cases where other agents are stumped. But even those agents have a past. He is leading his agents as they try to track down a serial killer of past serial killers. There is lots of technical crime investigation details that develop a pattern that will evaluate FBI and its structure as the killer is hunted. This is fast paced with building tension and horror in this wild read. Grab this adrenaline filled thriller/mystery! #peachypages

The narrator does a fantastic job, and the audiobook flows nicely with great clarity. However, this book just didn't resonate with me. I found the main character to be a bit of a copycat, and each scene felt too predictable, like a less engaging version of stories I've encountered before. The writing and characters failed to capture my interest.

"The Head Cases. We’d been called this moniker a lot, but rarely to our faces. Like most FBI nicknames, it was half insult, half compliment. After all, we did have good “heads for a case.” We had the ability to synthesize. To see things others couldn’t. To connect disparate elements into one unified story. But the name meant other things, too. That we were oddballs. Rejects. Nutsos. Not my words. But words I'd heard used to describe us."
Head Cases is a fantastic novel that delves into the mind of one of the smartest FBI agents there is, Gardner Camden. Gardner works for the PAR (Patterns and Recognitions) unit, along with other FBI "misfits". The author doesn't explicitly state it, but Gardner is neurodivergent. He has an amazing memory and an uncanny ability to make connections that others cannot, however, he is like a fish out of water in social situations. Poor Gardner stays true to his moral compass which causes him a lot of heartache (i.e. sending his wife to prison for money laundering).
Gardner has just been sent to the scene of a murder. The strange part? The man that was murdered was a serial killer Gardner has found many years ago... who died in a house fire with dental records to prove it. Not 48 hours later, Gardner is called to the murder of another serial killer who was just released from prison that same day. What is going on? Is there a connection or is it a strange coincidence? Gardner and his team of misfits must work together to find the killer who is targeting serial killers before time runs out- for the bad guys and for PAR themselves, who just discovered their unit is on the chopping block. There is a definite cat and mouse game at play and it's a race to see who comes out on top.
I absolutely loved this novel. The audio was fantastic! I certainly hope that this becomes a series. 5 stars! Thank you to NetGalley, Minotaur Books, and Macmillan Audio for the ARC!

Head Cases is one of my favorite books this year and it is coming out in January 2025. I read the audio version with excellent narrator Will Damon presenting.Gardner Camden and his colleagues in the Patterns and Recognition (PAR) unit are FBI agents who each have committed some petty faux pas that landed them in a lousy geographic location. They get called in when brilliant but not conventional minds are needed. Gardner's lives in his head and is very poor at recognizing social and emotional cues from others. His psychiatrist mother raised her "different" boy with love, allowing him to explore the many things that profoundly interested him. The head of the unit is Frank. Then, there is Shooter, whose nickname speaks for itself. Having listened to audio, I'm suddenly blank on the mathematician's name. She definitely flirts a bit with Gardner and her math skillls make them somewhat alike, although her social skills are just fine. I also forget the name of the weapons buy. But there are an amazing ensemble cast and a lot of fun. Rounding out their group is Richie, first in his class at Quantico, who unaccountably wants to be assigned to PAR. Most newbies want to be in a high crime area performing high profile work. Not in the backwoods with a bunch of disgraced agents who are called on for only the most confusing of cases. One could say that the unit's nickname, the "Head Cases" has many layers: a bit "off"; each brilliant; each clever...
When the novel opens, there is a death out west. The body is identified as that of a serial killer who Gardner chased after with his former partner until the man died in a house fire. Oops. He did not die. PAR is assigned to field work! As they begin to investigate the morbid scene and to get their arms around the dead guy having been alive, more murders that seem to be related crop up. How were these people connected and what is the killer's reason for obviously involving PAR? Is the killer too a head case? Will he keep ahead of the unit to their end? They are definitively at their last stop in the FBI. This is a police procedural, a special unit story and a thriller at times. It is fascinating in its construction, the weaving of the characters, the perfect red herrings to the end and entertaining the whole time. I am seriously interested in this stand alone novel becoming a series. It is set up to win! I highly recommend Head Cases.

I don't read a lot of crime fiction so I was very happy when I venturing out of my comfort zone paid off. The stakes were high, the chapters were short and I was gripped very quickly. I blew through this book in a day I was so invested. The narrator was lovely to listen to and kept me even more engaged as the investigation took it's twists and turns. I loved getting to know everyone on the PAR team and I'm very excited to see where this series goes!

A perfectly fine police procedural. I had hoped the main character would be a bit quirkier based on the description. There were moments of tension and excitement, plus a few surprises along the way. Anyone who is a fan of this type of book would like enjoy the overall plot.
The audiobook narrated by Will Damron was likely the ideal way to read this book. He provided a voice that I expect to hear in police/FBI drama. He was also easily understood at faster speeds.
Thank you NetGalley, Macmillan Audio, St Martin’s Press, and author John McMahon for the ARC and ALC in exchange for my honest review.

Although off to a slow start, the story quickly ramped up and omg I could not stop listening! The story was compelling, the narrator was terrific, the characters were believable and well fleshed out. And when you think you have it figured out, you find out you don't. This was a well thought out plot, a well written book and I am hoping there's a next volume in the works - I would hate to lose Gardner Camden and the Patterns and Recognition Unit so quickly after meeting them.. Serial killers must be a thing right now - I'm reading another ARC right now about .... a serial killer killing serial killers. It's a good time to be alive for us serial killer story lovers. There was a lot of action in this book, including movements of the main characters from place to place. It did get a bit difficult to keep up with who was going where, and that is the only downside, in my opinion, to this book.
My audiobook ARC was provided by NetGalley, the opinions expressed herein are strictly my own.

I love a good police procedural and stories involving serial killers. I was initially hooked on this premise and thought the first third of the book was hard to put down. Things got a little slower in the second half and whole Grady was fine as a MC, I didn’t really feel connected to him. I would be interested to read more from this author and learn more about Grady.
Thank you to NetGalley and Macmillan Audio for the advanced copy in exchange for my honest review.

Thank you so much to Macmillan Audio for the gifted audiobook!
I flew through this book in a day- it was a fun and easy-to-read police procedural.
I loved the main character/FBI agent Gardner Camden quirks and all. He was easy to root for!
The story was fast paced and I was trying to guess what would happen, but the ending totally surprised me! This will be a huge hit for sure!
I'm so excited that this was the start of a new series and will definitely read book two!

Let me just tell you that if you are a lover of Criminal Minds, you will thoroughly devour this book. It is a fast paced, shockingly intense, brilliant read. I was at the edge of my seat the entire time I was flying through the pages. My heartrate up, my breathing fast, my palms sweat, the hair on the back of my neck sticking up. I felt eyes tracking my every move, worst case scenarios forming in my mind. I was utterly sucked in by the first sentence. My eyes roving over the words, trying to form patterns, and pushing my mind to complete puzzles from the few clues the Patterns and Recognition team with the FBI were given. They normally work cold cases, yet this time they are leading. Making this one piece of the complex puzzle.
Gardener has a brilliant mind. He can remember every little detail, recall anything he has read or experienced, he is the perfect FBI agent. Except he cannot read social cues. Gardener has always known he has been different, his mom helped teach how to make it a positive. Yet he still struggles. When this case lands in his lap, he does not know who to trust. A serial killer is targeting other serial killers. Do they really want to stop him? Or let him be a vigilante. Allow him to take out the trash and clean up the killers who have gone dark or just been released from jail. As the plot thickens, more questions bubble to the surface. Making this the perfect crime to dismantle and put together again.
I am beginning to enjoy audiobooks people. I know who would have thought I would ever say that. The narrator is suburb, his voice adding a layer to the book. Helping to draw me into the story. Allowing me to envision Gardener with a sharper focus. This book can get a little gruesome at times. But the dashes of humor had me laughing out loud. Thank you to John McMahon, Minotaur, and Macmillan Audio for this thrilling read.

“Head Cases” by John McMahon is about a search for a serial killer who is out to killing other serial killers. To find the killer, a specialized unit is brought in to solve the case. Gardner Camden has the ability to see strange patterns and numbers unlike anyone else (think Sheldon Cooper - Big Bang Theory). Along with other unique agents on his team we follow them across country as the victims add up and clues start coming fast and furious. I have seen this book compared to Criminal Minds and I would agree. If you are looking for a smart thriller I would definitely try this one!

I really enjoyed this one. The narrator was great!! I love serial killer stories! The characters felt like real life people. I felt like I was reading a real crime story. And didn’t end in a cliff hangers or is that just me. Because wouldn’t be mad for more!