
Member Reviews

We have all watched crime shows that follow behavior analysis. This book was better than the crimes shows I usually watch. The narrator switched through characters flawlessly, and gave them each their own feel. The story line had me chasing my tail the whole time. Every time I thought I had it figured out, my theory got blown out of the water. My favorite part of the Book is the main Character. Gardener Camden was fascinating to me. His intellect and focus, along with his uncanny way to analyze the evidence was pure magic. I also loved how his fellow agents respected his quirks, and never failed to back him up. Loved this as an audiobook, but will read the hard copy as well.

Intense, shocking gripping, and hard to put down, Head Cases is an awesome book! I was instantly hooked and on the edge of my seat as I listened to the wonderfully narrated audiobook version of this riveting book! This is the first book in a new series, and I am already hoping with fingers crossed that John McMahon is already working on the next book!!!!!!
FBI Agent Gardner Camden is not like other FBI agents. He has a penchant for solving puzzles as do the other members of the PAR unit - Patterns and Recognition. They are a quirky, intelligent, and unusual group of agents who look at cases differently. They are called in to investigate when a murder victim is linked to a serial killer, they believed has been dead for some time. They will utilize all their unique skills to not only uncover the killer's identity but to bring the killer to justice!
This book was excellent. Gardner was a great fully fleshed out character. I enjoyed his thoughts, his determination, his approach to the case, and his courage. I also enjoyed his mother as well. I loved the interactions between the team members and how they worked together. They are an interesting bunch, and I enjoyed how they contributed to the investigation. I also loved the tension, the dread, the mystery, the sense of danger, and the taunting of the killer throughout the book. Fans of Criminal Minds or similar programs will love this book! What am I saying, readers who like gripping, shocking, well thought out, wonderfully written mysteries, and intelligent books will love Head Cases.

This is a must read for police procedural thriller lovers! A bit Monk meets Criminal Minds.
I loved the MC, Gardner Camden - he’s unconventional and complex. All of the characters are well-developed and the writing is outstanding.
I really enjoyed the mentions of several familiar locations in Florida.
Excellent narration and there are a lot of laugh out loud moments.
Looking forward to the next in the PAR unit series.
Thank you to the publisher for the opportunity to read this advanced copy. Opinions expressed in this review are completely my own.

The Patterns and Recognitions (PAR) unit of the FBI is made up of misfits, agents who all made some mistake in their previous assignments but have unique skills. I love the idea of this type of an investigative unit. They remind me of some of my favorite TV detectives, Monk and Will Trent, to name a few. They see things that others miss. While the crimes were a bit graphic, they were cleverly investigated in a way that made me happy to be in the minds of these agents. If you like police procedurals with unique characters, this one is for you!
Can we talk about Will Damron's narration? Spot on. There's something special about the way he makes me feel like I am actually standing next to Garder Camden as he talks through the case. Damron has become one of my favorite narrators for just this reason.

Very intricate plot that was so well-executed!
When a case is too difficult to solve, a group of brilliant yet quirky agents from the PAR (Patterns and Recognition) unit are called in. This time, it's to catch a killer who is hunting OTHER serial killers and leaving clues and riddles in his wake.
This story reads like an episode of CRIMINAL MINDS. We get to know our investigators, particularly the lead FBI agent Camden. I was so intrigued with the plot and how Camden's mind worked out the clues to get a step closer to catching the killer. Suspenseful and twisty, if you love police procedurals and stories about capturing a serial killer, this one is for you!
I can't wait to continue this series!
4.5 stars

Gardner Camden is neurodiverse, something his beloved mother has taught him to see as a gift and to manage in the real world as he was growing up. In fact, his brilliant analytical mind and talent for solving puzzles has made him one of the FBI’s most interesting agents. What he lacks in interpersonal skills, he makes up for in methodically solving cases other agents can’t.
His team, the Patterns and Recognition Unit (PAR), includes a group of quirky but skilled personnel who are loyal to a fault: a career agent, a weapons expert, a math whiz, and a computer analyst. Aside from his young daughter, this is his family.
Camden is made lead on a case he worked years prior when DNA connects a murder victim to a serial killer who was supposed to have died years before. His death mimics that of his victims, the killer leaving clues that set the team in motion.
And then, there’s another victim. Another clue. Another victim. Another clue.
When it becomes clear the clues are meant specifically for Camden, the team - normally relegated to desk work - hits the road to travel the south from Alabama to Texas to Arizona as the killer sets a trap.
The serial killer is killing serial killers, but what does it mean and where will it end?
This procedural works because of its fantastic characterization, the unique voice of Camden, and exploration of the motivations of the killer and the agents. It’s psychological aspect, as much as the descriptions of the gore, that push this to the top of the class.
As the first book in the series, McMahon has set something special in motion. Laying out an unexpected backstory for Camden and creating an enigmatic supporting cast capable of being the focus of any subsequent book in the series feels exciting.
Narration by Will Damron is perfection, his delivery both subtle and nuanced.
This is a series I eagerly anticipate reading as each novel is released. It’s fantastic, filled with tension, action, mind games, and red herrings.
Don’t miss out!

This book keeps you on your toes if you’re a fan of serial killer stories and FBI tactics. The FBI unit, called PAR (Patterns and Recognition) is made up of a variety of unique members with non conventional ways of thinking.
A serial killer is hunting other serial killers who got away with their crimes. Something is wrong, the murderer knows more than they expected. Is someone in the FBI feeding him information? Detective Gardner Camden has been given the chance to lead his first investigation. They noticed clues that hopefully will crack this case open.
Thank you NetGalley, Macmillan Audio, & St. Martins Press for this ARC copy for an honest review.

While the success of a team of misfit detectives who manage to get the job done in their own ways may not be a new plot line, The characters in HEAD CASES are originals and are very good at their job, well, they are good at this job. Each member of the team has been placed in the PAR Unit after their particular skills landed them in hot water elsewhere. They are originally assigned to apply their pattern recognition skills to cold case reviews. BUT, when a serial killer's body is found, it raises alot of questions to which this team must find the answers.
This is slated as the first book in a new series built around the PAR team. John McMahon has had success in police procedural series, he's the author of the PT Marsh series, an excellent series itself, but has given the cast of the PAR Unit a human touch. Their differences were divisive in the prior jobs, here, their differences make them unique members of a unit ready to prove their abilities as they wreck havoc on the FBI. The personal background of each will be excellent stories in the coming series. 5 stars for Head Cases. Can mcMahon do it again?
I read and listened to an audio book of this story. Each was equally good with the audio adding an extra element to the book. Readers will be happy with either version.

This was a fast paced thriller with characters that on their game! This kept with the theme the whole way through and kept the suspense level very high thought out the book. I was engaged and hanging on the edge of my seat the entire time. This was a top read.

I really hope this book is the start of a series because I LOVED it. It gave NCIS, CSI, and Criminal Minds vibes! A SERIAL KILLER KILLING OTHER SERIAL KILLERS … now that’s different!!! I was immediately hooked by this book. The PAR unit made of FBI misfits that all bring their own skills to the team was genius. Those are the people you need on the team! They are going to get the job done. I guess that’s why they call on them when it’s a case they can’t solve. Im definitely adding it to my list of physicals I need to get on my shelf. The narrator did amazing and gave the story a more realistic feel. Agent Camden wasn’t not going to quit be any means and did what he knew was the right thing to do, even if it cost him his job in the long run. I can’t wait to read the book 2!

I thoroughly enjoyed this audiobook! The narrator really captures the voice and mannerisms of the main character Agent Gardner Camden. The neurodivergent special agent in the FBI unit known as PAR finds himself in the midst of a case that becomes very personal very quickly. This loveable bunch of FBI misfits knows how to get you wrapped up in a thriller any fan of crime tv shows would enjoy. I can’t wait to read more from the PAR unit!

Thank you to @macmillan.audio for the advanced audiobook! What a pleasure to listen to.
If you’re a fan of shows like Numb3rs, Criminal Minds, or Mindhunter, this is one you won’t want to miss when it hits shelves on 1/28!
I absolutely loved the PAR Unit and couldn’t put this book down. The story is fast-paced, action-packed, and rich with detail. Following the unit on the road and getting to know each member—each with their own unique personality—had me hooked from start to finish. By the end, I was completely invested.
And can we talk about the narration? Will Damron was *perfect* as Gardner Camden. I can’t wait to listen to more in this series!

A flawless thriller worth diving into head first!
"Head cases" is what their colleagues at the FBI call Special Agent Gardner Camden and his team, known as the PAR (Patterns and Recognition) unit, behind their back. They are an unlikely group of often socially awkward outcasts with brilliant minds. All five agents have specific skills, like Camden's affinity for solving puzzles, but most of them have a few burned bridges behind them that ultimately led to them being stranded at PAR.
When a serial killer is murdered, and a pattern soon points to the work of a (serial) killer who seems to be hunting serial killers that escaped justice (such an intriguing concept!), Camden and his team - usually relegated to working cold cases out of the public eye - are tasked with taking the lead in the investigation. But Camden is soon drawn into a very personal play of cat and mouse with the perpetrator whom he must try to outwit.
Flawless and atmospheric, "Head Cases" has everything you could ask for in a great procedural: well-developed, complex and intriguing main and secondary protagonists, a smart, gripping case, perfect pacing, and impeccable writing. I listened to the audiobook version, which was equally superb - the narrator did an outstanding job of voicing the story and its very unique characters.
This was easily one of the most intriguing and genuinely unique mystery / thriller books I have read in a while, and I am very happy to hear this is the first installment of a new series.
Many thanks to NetGalley and Macmillan Audio for the ARC in exchange for my honest review.
"Head Cases" is slated to be released on January 28, 2025.

ɴᴇᴛɢᴀʟʟᴇʏ ʀᴇᴠɪᴇᴡ || HEAD CASES [thank you to @minotaur_books and @netgalley for my #gifted copy!]
Title: Head Cases
Author: John McMahon
Genre: Suspense, Thriller
Format: Digital
Star Rating: ★ ★ ★ ☆ ☆
ꜱᴜᴍᴍᴀʀʏ:
FBI Agent Gardner Camden and his team of brilliant misfits must crack a killer’s deadly riddles—but as the murderer closes in on their personal lives, the stakes become terrifyingly personal.
ᴍʏ ᴛʜᴏᴜɢʜᴛꜱ:
This book was a wild ride - if not, ultimately, like watching an episode of tv that isn’t my favorite but gets the job done.
If there’s one thing that I like about Spencer Reid, it’s that he generally walks you through how his brain comes to a conclusion - & that was missing here. 🤷🏻♀️
I always prefer it when I’m able to try to follow the dots myself, rather than having the author tell me what the dots are. So that was a miss for me. But this was a quick, easy read if you’re looking for an escape!
ʀᴇᴀᴅ ɪꜰ ʏᴏᴜ ʟɪᴋᴇ:
Criminal Minds
Police Procedurals
Mindhunter
Zodiac
Fast-Paced Mysteries
ᴅᴇᴛᴀɪʟꜱ:
GR: 4.25 ⭐️
# of Pages: 352
Pub Date: January 28, 2025

I am super excited that this is the start of a series b/c I really enjoyed this book. It was an engaging read and I was hooked from the beginning. I really loved that Agent Camden would not quit and did what he felt was right, even if it lost him his job. I can't wait to read book 2 in this series.

4.5⭐️
A serial killer killing other serial killers? Immediately hooked. I love any type of FBI/serial killer trope book and this one is at the top of my list of favorites! Gardner reminded me so much of Spencer on Criminal Minds! I loved him👏🏼. I personally wish I would have physically read this book vs listened on audio. The audio was great, that is definitely just a me preference with books like these that have a lot of info that I need to retain and remember. Overall, really enjoyed this and hope to see and read more books in the PAR Unit series soon!🤗
Also, I love that book cover!
Thank you NetGalley & Macmillan Audio for the ARC! Head Cases is out January 27th. Be sure to add it to your TBR!

Do you enjoy following the trail of a serial killer? If you do, then this is the book for you! This book introduces a new series of books about the PAR (Pattern And Recognition) unit of the FBI. Gardner Camden is a deeply flawed character who uses his weaknesses to his and is team’s advantage in investigating this case. He leads the team effectively and learns a lot about himself along the way. This first book of the series tells the story of their pursuit of a serial killer who they had initially thought was dead. Similar to Criminal Minds, this book takes you through all the thrills, chills and feels of chasing down this serial killer.
I highly recommend this book to anyone who loves suspense, thrillers and rollercoasters! I am very excited for the next installation in this series and can’t wait to hear more about this team (the other characters). The narrator was excellent and really made it all the more thrilling!
Thank you to Net Galley and Macmillan Audio for this ALC in exchange for my candid review!

PAR. A special section of the FBI gets a new case. A presumed dead serial killer is found dead, and the next day, a recently released from prison killer is also murdered. Gaudy and his colleagues need to find this dexter like killer, who is killing killers, before it’s too late.
Complex and fun. Definitely kept my interest throughout as we follow the team, following leads and trying to find out who this killer is. I will enjoy continuing to watch the team.

A interesting new detective series. I have been on the hunt for a new long time series and this book is a good prospect. I have been reading Karin Slaughter and Pat Cornwell for ages and this ranks up there.
A quirky detective, a team full of misfits...makes for the perfect crime solving team. I was invested in the main character and my only criticism being that the neurodivergent eccentric detective role. It's been done more than once ranging from Criminal Minds to Monk. The writing was decent and the story well written so I can forgive that. Would have been better done if the author had let the reader come to that conclusion, not making it so obvious. I do appreciate the twist at the end. Don't want to give spoilers.
I would read the next book in this series.
I highly recommend the audio version of this title. The narrator has a smooth voice that I imagine to sound a lot like the main character. Fits well, I did speed it up to 1.5x as he did talk a tad slow for me.

This was such a good book. I loved the story and the writing so much. The characters were great and the story flowed smoothly. Will definitely read more books by this author in the future. It was very much like watching an episode of criminal minds and I liked that.