We chat with author John McMahon about Head Cases, which follows an enigmatic group of FBI agents as they hunt down a murderer seeking his own justice.
Hi, John! Can you tell our readers a bit about yourself?
Hi. First off, thanks for having me. I’m a Southern-California-based writer, but have lived all over. I was born in the Bronx and grew up there and in southern Arizona. Moved to California as a teenager. I still work a day job as a creative-director in advertising, which I enjoy a lot. And then write in the evenings and on weekends.
HEAD CASES is the beginning of my second series. (The first is a police thriller series based in Northern Georgia that began with THE GOOD DETECTIVE).
When did you first discover your love for writing and stories?
I was always writing as a kid. But I didn’t grow up in a family where we knew anyone who worked in the arts. We didn’t know any painters, musicians, graphics designers, or writers. So like a lot of people, writing wasn’t on my radar as something that was a ‘real job.’ I came out of college, worked two years in finance, which wasn’t for me– then decided to go back to school and study creative writing in Tucson. That’s when I first wrote anything serious, initially just poetry and short stories.
Quick lightning round! Tell us:
- The first book you ever remember reading: There was a series by E.W. Hildick with a kid detective called Jack McGurk. I don’t recall the title, but it was a great ensemble and I remember there was a character called “the nose.” My mom would ‘force us’ to check out a book from the library every month, and I loved those books (and little else).
- The one that made you want to become an author: Been Down So Long Looks Like Up to Me. Richard Farina’s debut (1966) – I picked it up randomly at a bookstore when I was 21.
- The one that you can’t stop thinking about: The Jealous Kind by James Lee Burke. Burke is my favourite author. His novels are sweeping epics that are also thrillers, family stories, love stories, etc. They have deep details and storylines. Expect a single page of description on a door. I love to read everything Burke. I also love them on audio, with Will Patton narrating. He’s such a pro.
Your latest novel, Head Cases, is out now! If you could only describe it in five words, what would they be?
Misfit FBI Agents pursue serial killer.
Okay, that’s 6 words.
What can readers expect?
As a reader myself, I get hooked on characters that pop off the page. And that’s what people seem to love about HEAD CASES.
Gardner Camden is a bit of an oddball, super-intelligent, and often oblivious to those around him. He’s surrounded by a group of agents within a team called PAR (Patterns and Recognition) at the FBI. Their job is to identify patterns or peculiarities that no one else can see… then send the file back to a field office, local cops or to Quantico.
But in this case, they are sent on the road themselves to chase a serial killer, something that PAR has never been asked to do because they are not fit to interact with the public or local cops.
Along with Gardner, PAR consists of a mathematician, a weapons expert, a computer analyst, and their leader, a career agent. So they each come to the case with a different skil setl. What advance readers seem to like is that they all appear like fleshed out people you know, not caricatures.
This is also a book full of puzzles and riddles, so to solve the identity of the killer, it’s going to take everyone on the PAR team and each of their strengths.
Where did the inspiration for Head Cases come from?
I was exploring this idea that sociopaths and cops might share some of the same traits. I started thinking of the extreme example of this, and drew up the main character of Gardner Camden. And at the same time, the book’s antagonist too.
I typically try to figure out an opening that makes a character uncomfortable, because like in life, it’s in those situations where we see who we actually are.
So Gardner is sent to a crime scene where he IDs the body of a serial killer that he ID’d as dead 7 years earlier. But if Gardner never makes mistakes, how is that possible? Then, when a second serial killer turns up dead, a pattern emerges. Someone is killing murderers. But to do this, they’d have to know information known only to the FBI… so someone in law enforcement is involved.
Were there any moments or characters you really enjoyed writing or exploring?
I loved writing the main character of Gardner Camden. But he was also challenging to write because he has an extremely low affect and sees the world in a very particular way.
My other favorite was Cassie Pardo, Gardner’s partner. Cassie speaks in the slang of a 20-year old (and I have a 19 and 21 year old), so I was constantly taking notes of everything that they (and their friends) would say. One early review gave the book 4 stars instead of 5, citing there was a character that sounded annoying like the reader’s daughter. Success! I thought. Made my day.
Did you face any challenges whilst writing? How did you overcome them?
The biggest challenge during this book was not writing-related. Early in the writing process, I flipped on a boogie board and crushed my C5/C6. Other issues followed, and I had 4 cervical spine surgeries in a period of 2 years. I am still dealing with it. Getting better is a back-and-forth thing, and hard to know if progress is happening most days. So I had to figure out the best times to write– and the best places to write. I put a board over my Jacuzzi as a desk, so I could soak in the hot water while typing away. But HEAD CASES is getting amazing reviews and no one seems to notice that it was written amidst pain. So maybe pain is part of the recipe?
What’s next for you?
The next book in the HEAD CASES series is with my agent already, and I will get notes any day from her and begin revising. But there’s been several gaps in time, and I have a deep need to produce words every week. So I have 200 pages of a family story- something very different than I’ve written before… which I am in love with. And I have 300 pages of a genre-bender (part psychological horror, part police procedural) that I think will be great too, but will take a lot of revisions to balance genres.
HEAD CASES is also in development at HBO MAX, and I’ve met the showrunners adapting it. So I am excited to see what happens there. Anything in Hollywood can die in a second, but MAX seems intent on pushing this forward.
Lastly, what books are you looking forward to picking up in 2025?
I am moderating a panel at the Tucson Festival of Books, and when I do this, I always read each panelist’s books. So I am currently reading The Puzzle Box by Danielle Trussoni and really enjoying it. Beyond that, I’m careful not to build my TBR too big anymore, just because of health issues with my spine and having to keep up my page count on my own books. During this time, I have become a huge audiobook person.
