Whiplash! This books has some many different story lines-it was so hard to keep track of where you were in this book. I really had to pay attention to follow along. Overall it was ok.

Thank you to the publisher for making this available to read through NetGalley for its influencer program.

Head Cases centers around FBI Agent Gardner Camden and the Patterns and Recognition (PAR) unit, a quirky group of misfits tracking down a killer out for his own brand of justice. I found it well paced and smoothly written--I had a hard time putting this down once I started. But at the same time, there were a couple things I'm not entirely sure of.

First, and I realize this might be entirely subjective for me, but for crime fiction to really work, you have to have sympathetic victims to create immediacy in the plot. You rally around law enforcement if the killer is going after innocent children and damsels in distress, if you will, and there's an element of suspense not knowing who the next victim will be and if they'll be saved in time. The choice in Head Cases to make the victims serial killers, while interesting and different, takes away that suspense. Quite frankly, take your time, FBI.

Secondly, and also subjective--the characters themselves. I liked them all well enough; the PAR team is a likable crew. But there's something a little cliché about Camden and Shooter in particular--one a socially inept genius who'll be able to pull facts no matter the subject, and the other an Olympian, literally a "shooter," that again took away some of the suspense for me. That they'll be successful never seemed to be in question.

That being said, if this will be developed into a series, I would definitely check out book 2, hoping that the elements I was missing are there. But not knowing anything about a second installment, I'm not entirely sure if I would recommend this. A solid read nonetheless, 3.5 stars that I would round to 4 because I liked it in spite of the problems I had.

Head Cases is a fun book to read if you’re a fan of Criminal Minds. A team of FBI agents attempt to track down a serial killer of serial killers. I really liked the concept of this “rag tag team” of agents with very specialized talents being a specific group that solves cold cases. The overall plot is good, although a little too procedural at times. The writing is strong, but the written dialogue for Cassie’s character was cringey a majority of the time (the gen z language felt so forced). The end definitely felt like there was a door left open for a potential series. I think with a little more character development, this would turn into a strong series. (4.25/5)

**This ARC was provided by the publisher via Netgalley in exchange for an honest review.**

Thank you to NetGalley, author John McMahon and St. Martin’s publishing group for the ARC and opportunity to review this book.

3.5 stars rounded up. This was my first by this author and I quite enjoyed it. I loved the characters and would hope to see this ‘crew’ become a series if they aren’t already.

The storyline was good, it kept my attention but I feel it was missing something to make it a little more gripping and suspenseful. I felt it jumped a bit too much and had to re-read a few parts to make sure I was understanding which character, which crime scene etc but the author tied it up nicely in the end.

I would recommend if you are looking for a slower paced brain teaser type of book. I felt it would make a great episode of criminal minds!

3.5 ⭐️⭐️⭐️

It took me a while to warm up to Gardner and his Head Cases in the FBI PAR special unit. Their idiosyncrasies come together to solve a crime of serial killer killing serial killers. Office politics play a large part as the navigates their rumored demise. its intensity reminds of Criminal Minds. I love the relationships Gardner has with his mother and daughter. I will definitely read what comes next.

Copy provided by the publisher and Netgalley

Thank you to NetGalley and St. Martin’s Press for this ARC!!!


I would change absolutely NOTHING about this novel. It literally felt like reading from Spencer Reid’s mind from Criminal Minds. I finished this book in less than 24 hours because I could not stop. Definitely hope this turns into a series.

I flew through this book! I really enjoyed the story line and the true crime/FBI/criminal minds feeling. I also loved the plot twists and the constant chase through the entire book. I appreciated how focused to the hunting criminals plot this book was, without many side plots that distracted from it. I’m taking a star off because I felt like I was able to predict a few of the bigger plot twists and didn’t love the way this ended. I did appreciate that this was a stand-alone and thought it was overall well done!

If you're craving a page-turner that will give you the perfect escape during nap time or after the kids are in bed, you have to check out Head Cases! This book is packed with suspense and drama that will keep you hooked from start to finish. IT’s the perfect "me time" book!

Head Cases by John McMahon is a fast paced police/FBI procedural crime novel. Gardner Camden is part of the PAR unit of the FBI, which is a Patterns and Recognition group of four agents. These agents are used when others in law enforcement haven’t been able to make headway in a case, PAR being a fresh set of eyes for such a case. Agent Camden is a unique individual, probably considered neurodivergent, and sees numbers and patterns unlike anyone else. He is also an extremely likable character who readers can instantly connect to and root for. The rest of the crew have their quirks and individuality as well, and it is obvious they are more family than just coworkers.
The case PAR is brought into on page one is the murder of a serial killer thought to have died seven years prior. The killer left clues seemingly for Camden himself. And before you know it, he kills again. A serial killer killing serial killers!
Off we go on a nonstop journey from Florida to Texas to California and back again, piecing clues to the puzzle together to solve the crime. Camden’s personal life gets involved as well, which just adds to his humanness as a character.
I was impressed by how realistic the conversations were and honestly at times felt like I was part of the unit trying to solve this crime. It definitely gives you an image of intense excitement being an FBI agent, which was a childhood dream of mine, so a fun reading experience. I would liken this to Sherlock Holmes with his quirky and clever mind or genius Spencer Reid from the show Criminal Minds. If you are a fan of this genre, I think you will really enjoy this read. And P.S. there are plans for a sequel which I will definitely pick up. Thanks to NetGalley and St. Martens Press for my ARC.

A scooby-doo rag tag gang of the FBI who have been shunned make up the PAR, Patterns and Recognition Unit. FBI agent Gardner Camden is lead of this group, and with his brilliant mind but awkward social skills, make up this stunning thriller and police procedural novel.
An absolute binge worthy read and great for everyone, even those who don't fancy themselves as crime junkies!

I loved this one it kept me guessing the whole way through! This is a perfect Fall thriller I highly recommend!

Head Cases follows Agent Gardner and the PAR (Patterns and Recognition) group that handles cold cases. When they get a call for a murder victim whose DNA links to a man that Agent Gardner believed to be dead, it sets the PAR group on a hunt for a killer who is targeting other serial killers. Can the PAR group who is used to working in the background, handle working on a current case in the public eye?

This book took me by complete surprise. I loved how different this book was from the mystery/thrillers I have read recently. Agent Gardner is the perfect main character for this book. It was nice to see a character that was neurodivergent, and I enjoyed reading his thoughts as he navigates through the case and how he interacted in social situations while leading the PAR team. This book had me completely engaged from beginning to end and the conclusion took me by surprise. The ending did open up the possibility of another book and I would read that in a heartbeat.

If you enjoy police procedurals and/or mystery thrillers, put this on your TBR for 2025.

Head Cases comes out January 28th, 2025.

Thank you to NetGalley and St. Martin's Press for the opportunity to review Head Cases. All thoughts and opinions are my own.

If you’re looking for a good thriller, check out Head Cases. This was a great read and it was so enthralling!

FBI Agent Gardner Camden is an analytical genius with an affinity for puzzles. He also has a blind spot on the human side of investigations, a blindness that sometimes even includes people in his own life, like his beloved seven year old daughter Camila. Gardner and his squad of brilliant yet quirky agents make up the Patterns and Recognition (PAR) unit, the FBI’s hidden edge, brought in for cases that no one else can solve! Great read!! This book had suspense, intrigue, action, murder, mystery, a great who done it and a few twists and turns. The story was interesting! I definitely recommend reading this book! Thank you NetGalley and the publisher for sharing this book with me!

I absolutely LOVED this book! The Characters were fairly fleshed out but i loved the plot and the writing from the main characters unusual point of view. I had never read this author before but I will now go back and read the rest of his stuff bec i couldn't put this book down!
I loved the cat and mouse, it was a very intelligent book, never boring!
Thank you to the publisher and NetGalley for the ARC!

**5 Stars for Head Cases!**

This book stands out as one of the finest police procedurals I have encountered. The narrative unfolds at a brisk pace, brimming with suspense. Special Agent Camden Gardner, who is neurodivergent, heads a team of FBI agents, each equipped with a unique ability to identify patterns and solve complex problems. I found it impossible to put down. The team embarks on a time-sensitive mission to track down a serial killer targeting other serial killers. I would be thrilled to see this developed into a series! Don't miss out on this compelling read!

Thanks to Net Galley and St. Martin’s Press for the ARC to read and review!

This was such a fun book to read! (Am I allowed to use the word ‘fun’ when talking about a book involving serial killers? LOL) I was pleasantly surprised by this book, only because I don’t think I’ve ever read a book with this type of plot before. I was worried that I might not enjoy it, but it turned out to be a really good book that I couldn’t put down.

This book follows Gardner, an FBI agent who is part of a subgroup known as PAR- the Patterns and Recognition unit. When a murder victim’s DNA identifies him as a serial killer they had presumed dead over 7 years ago, their team is thrust into a cat and mouse chase with a man seeking vengeance against other killers.

Fans of Criminal Minds will really enjoy this one! As someone who majored in crime scene technology myself, it was really fun for me to read about a lot of the “behind the scenes” when it comes to solving the case. Yes, it’s not a real life case, but the writing made it feel like one! I truly felt like I was part of the team and was learning information and putting pieces together alongside the characters. If you’ve ever wished you could be part of the Behavioral Analysis Unit alongside Spencer Reid, this is the book for you.

WOW this was perfect! It was unique, it was a bit old school, it was realistic and it was impossible to guess.

Head Cases follows a group of Slow Horses types -- FBI agents that were churned out of the FBI machine because they couldn't keep up with the politics. Their punishment is to deal with cold cases via a program called PAR (Patterns and Recognition). FBI Agent Gardner Camden is an analytical genius with a remarkable memory. His recall rivals google and most of his colleagues dislike his abilities and his inability to fit in. But at PAR he has almost a family and the group has been successful until now.

Gardner learns early on that a man he had filed as dead just recently was murdered. This mistake sends him spinning and he and the team are called in to a live case. It's not long before they learn that they are just as much part of the case and there is a serial killer at large!

I just loved this book. I felt Gardner was very well written and believable - not the over-the-top spectrum or confused with social skills writing that some authors employ for entertainment value. We really know him and root for him! I cannot wait for the next book and am going through MCMahon's past books now! #StMartins #headcases #johnmcmahon

🚔 BOOK / REVIEW 🚔

I have been in a book rut 😭 I recently started crocheting, and that has taken up my time and interest over the past few months, so this one got pushed to the back burner for a bit.

That being said, this was an EXCELLENT #policeprocedural novel - McMahon wrote the plot, characters and twists / turns perfectly. I loved that this one focused on a unique group in the FBI - called PAR - comprised of genius minds and a ragtag group of friends. The fact that I learned so much while reading this makes it a very easy book to recommend for folks who like this genre. Despite my lack of time, this is actually a very quick read.

All of the early reviews for this are incredible, so be sure to add this to your queue! #headcases by John McMahon publishes January, 2025 by @stmartinspress. Thank you so much for my #gifted copy @netgalley.

⭐️⭐️⭐️⭐️💫

My series loving heart wants every book I enjoy to become a series, and that is true here. I loved Gardner and his crew, and the story was good! I actually emailed the author I enjoyed it so much. Thanks to Netgalley for the free advanced copy in exchange for an honest review, book publishes January 28, 2025