A book about serial killers with a main character who has difficulty with social situations and an eidetic memory? Sign me up! I started out listening to this book but then wanted to finish it sooner so got out my kindle and finished it up in a couple hours.
This book follows the PAR team at the FBI. A rag tag group of misfits as they race to solve a case that they can’t get ahead on.
I honestly loved every minute of it! Can’t wait to read the next one.
I received an ARC of this title, all opinions are my own.

The head cases are a group of FBI agents that specialize in Patterns and Recognition (PAR)
When Gardner Camden, one of the PAR unit, is called to a crime scene, he finds out that the deceased man is a serial killer that he found at a crime scene seven years ago. Now he’s on the hunt for the serial killer that kills serial killers.

This book was narrated by Will Damron who did so well 👏🏻 the story immediately sucked me in, and I had a great time listening / picking up my e-arc at times I couldn’t listen.

This one is for fans of David Ellis and James Patterson! I love a good police procedural with quirky characters and this one delivered.

Thanks so much to NetGalley, St Martin’s Press for my ARC and Macmillan Audio for my ALC.

Pub date 01.28.25

LOVED LOVED LOVED!!!! And am so excited that there will be at least one more book in this new series!!
McMahon's writing is exceptional and these characters he's created for this series, the "misfits" of PAR unit, are so amazingly relatable that I fell in love with all of them, especially Agent Gardner Camden. Loved getting into his head and reading how he thinks and reacts to things.. Loved the storyline, the twists.. I just could not get enough!! Bravo John McMahon! I'd give it more than 5 stars if I could!!

I was intrigued by the premise and as a Criminal Minds fan, thought this sounded up my alley. Unfortunately the execution didn’t work for me and I decided to DNF. Thank you to the publisher, Netgalley and Macmillan audio for the free ebook and audiobook to review.

Head Cases was a really solid read. It hooked me from the first few pages. 100% recommend if you’re a fan of Mind Hunter! Same overall vibe, really enjoyed it.

This thriller, while initially slow to ignite, ultimately delivers a compelling and unique premise. The concept of serial killers being hunted down by a mysterious force offers a refreshing twist on the traditional cat-and-mouse chase. The pace picks up significantly around the 50-page mark, captivating the reader with a series of intriguing events.

I particularly appreciated the insights into the inner workings of the FBI, providing a realistic and engaging glimpse into their investigative processes. The author's attention to detail, both in character development and procedural accuracy, added depth and credibility to the narrative.

Though the story could have benefited from a more polished edit, the overall impact remains strong. I highly recommend this book to fellow thriller enthusiasts, particularly those seeking a unique and thought-provoking take on the genre.

An engaging and promising thriller about a group of misfit FBI agents whose strength lies in patterns and puzzles. The main character, neurodivergent Gardner Camden, is looking into the murder of a serial killer who was thought to have died years earlier. As other serial killers turn up dead, Camden is dealing with both personal and work issues while racing to stop the killer. The book was fast-paced and short, which left little room for character development but kept me turning the pages. I look forward to future books featuring Camden and his team. Thank you to NetGalley and St. Martin's Press | Minotaur Books for a digital review copy.

This is an excellent police procedural about the Patterns and Recognition (PAR) unit of the FBI, and the agents who comprise the unit. This is the first book of a promising new series. They investigate very difficult cases, and this one is disturbing. This is an intricate story without being overly detailed, and held my attention. The small staff of the PAR have backstories that I want to know more about, and I can’t wait for more books in this series! Highly recommended!

Great premise, and great execution. Neuro-diverse detectives working together to solve cold cases... Gardner is the furthest out on the spectrum, but all of his partners have their own issues. I hope we'll get to know them more intimately in future books.

Thank you to MacMillan Audio (#MacAudio2924) for the ALC and Minotaur and Netgalley for the ARC!

I love police procedural type books, particularly when it involves a specialized unit. PAR (Patterns and Recognition department) was a unique department that I was quite intrigued by. Our MMC was the perfect person to lead it, as he is great with codes, puzzles and riddles. His no-nonsense approach to dealing with everything (except his seven year old daughter), made him, at times, feel like others didn’t know how to take him. But when serial killer from his past is found murdered, Gardner finds himself taking the lead on this case. With the killer leaving clues and puzzles, it’s a race against the clock to figure out who the killer could be.

Hearing Gardner’s perspective as he pondered everyday things - like if he should make a comment out loud or not - was truly eye opening as well and I love that the author included this! I really appreciated his character and how his mind worked. This appears to be the start of a series and I can’t wait to see what adventures are next.

“Headcases” releases January 28, 2025. This review will be shared to my onstage blog (@books_by_the_bottle) shortly :)

This is a magnificent game of cat and mouse. Members of an FBI task force is searching for a killer of killers in this pulse pounding drama. The author has created some very interesting characters that will stick with the reader long after they have closed the book. The plot is a minefield of twists and turns as clues are uncovered. My favorite scene is the one that sees one of the characters destroying the office. The author paints such a vivid picture that places the reader right in the scene. There is just so much about this book that makes it a very interesting read.

HEAD CASES is my first book by John McMahon and I’m intrigued to read more.

If you are a Criminal Minds fan like me then this is a must read. This read was part police procedural and part psychological thriller with serial killer vibes that had me furiously turning the pages, especially at the end where things got very suspenseful.

💭: If gore is not your vibe, then skip this one. Thank you St. Martins Press and Netgalley for the arc ☺️

What a fantastic police procedural! This was like Criminal Minds in book form and I devoured it!

McMahon gives us a cast of compelling characters, a break neck pace, and a mystery that keeps you on your toes. It’s packed full of tension, twists, and quirky but brilliant characters you’ll love.

Seriously, if you have watched an enjoyed Criminal Minds at all, you will live this one.

Gardner Camden has an analytical brain that is perfect for the PAR (Patterns and Recognition) unit of the FBI. With the threat of his unit disbanding, they are tasked with solving the murder of a serial killer they thought dead over a decade ago.

This debut novel from John McMahon is a binge worthy FBI procedural. He has developed a lovable misfit group of team members that have their own stories to tell. I appreciated Camden’s neurodivergent tendencies, challenges with social situations and his relationship with his elderly mom and daughter. This book kept me guessing all the way to the end. It does appear that this is set up to the be the beginning of a series and I look forward to spending more time with the PAR unit.

3.5/5 stars, rounded to a 3.

This is the first book in a new series following the Patterns and Recognition (PAR) unit in the FBI, a ragtag team of brilliant but misfit agents who use puzzles, codes, math, and other analytics to solve cold cases. Agent Gardner Camden is a brilliant agent with an eidetic memory, but his political disgrace and lack of emotional intelligence has set him back in his career. When a serial killer from one of his solved cases, previously identified as dead, reappears as a murder victim, a new investigation filled with puzzles and clues left by a vigilante is opened. But more than only the lives of serial killers are at stake, and the members of PAR need to solve this case quickly to protect their careers and the lives of those they love before it's too late.

I really enjoyed the team members in this book, I thought they each had their own personality that contributed to solving the cases. Additionally, the clues and puzzles were interesting and kept me engaged in the story. I love dark police procedural thrillers, and this really scratched that itch. This story loses some stars because some of the characters do feel a bit like caricatures. Gardner Camden gives huge Spencer Reid (Criminal Mind) vibes, with the amazing intellect, sick mother, and inability to read emotional situations. Another character is constantly speaking in text speak, which is a part of her quirkiness, but I think it really took me out of the story and reduced its believability. Ultimately, I do recommend the book - the final copy will be out January 28, 2025, and I will be picking up the next book in the series!

Thank you to NetGalley and St. Martin’s Press / Minotaur Books for an early copy in exchange for an honest review.

I can't praise this enough! Utterly gripping! Compelling writing and fantastic characters, I'm really looking forward to this series!

Head Cases by John MacMahon is a dark, psychological crime thriller that explores trauma, mental illness, and the complexities of the criminal mind through a gripping and atmospheric investigation.

I am so excited this is going to be a new series. I love the characters, the plot was well paced and I read it straight through in one sitting. Highly recommended.

Thanks to NetGalley and ‎Minotaur Books for an advanced reader copy.

Thanks to NetGallery for sending an email to alert me to this author and title and for providing the download. "Head Cases" is a great, fast paced mystery with a lot of twists and interesting characters. The main character, Gardner Camden, is brilliant at solving puzzles and observing anomalies with his FBI team, but also appears to be neurodivergent. The PAR (Patterns and Recognition) Team all have their own strengths to follow the trail of a serial killer who is targeting serial killers in a case that gets the team out of the office and into the field. It was fascinating to share Camden's thought processes to see the connections he made with information from his own observations and from the team to solve the case. I enjoyed this book so much that I have recommended it to readers to look for it on its publication date already.

John McMahon is a new author to me, so I didn't know what to expect when I received the ARC for Head Cases. I'm so glad I followed the lead of some of my Goodreads friends and trusted reviewers because it was fantastic. In fact, it's in my top five favorite books of the year.

This was not just another run of the mill crime thriller. The plot was so incredibly well crafted, with complex twists and turns, and characters that were each uniquely drawn. As much as I couldn't read it fast enough, as I neared the last page, it was the kind of book I didn't want to end. I really enjoyed my time with Mr. McMahon's characters -- especially his main character, narrator, Gardner Camden. It appears this will be part of a series of at least two books. I look forward to reading the next one, as well as the author's earlier books.

Thank you to St. Martin's Press, Minotaur Books and NetGalley for providing an advance copy in exchange for an honest review.