Who Is The Zodiac Killer?

511ShYCIo0L._SY200_When I found Kim McGath on Twitter I knew she would amaze you with her theory on the Zodiac killer. We’ve got a lot to get through, so let’s get right to it. Prepare to be thoroughly enthralled.

It’s a genuine honor to be a guest blogger for bestselling and highly celebrated author Sue Coletta (Note from Sue: I swear I didn’t pay her to say that, but maybe I should). I find her thoughts mesmerizing and her ideas, nothing shy of brilliant. She is an inspiration to so many. (*blush*)

Kim’s Background and Expertise

I never thought I would be in a position to be an author, let alone a detective. I have always lived my life by allowing my heart to lead the way, and never thought too much about future plans. I went to college, which I guess was the natural thing to do, and obtained my Bachelor’s in psychology, then began my career at a psychiatric facility and felt inspired by those who had so many struggles in life, yet pushed on despite their setbacks.

Blessed with a wonderful husband and three precious children, when my youngest entered kindergarten, it was time for me to return to the workplace. I cannot explain why, but I decided to enroll in the police academy. It was a gut feeling; I followed my instincts. Much to the shock and dismay of friends and family members, I became a cop.

My career started in patrol, but quickly advanced to the mounted unit. It was such a privilege to work with the horses; such majestic creatures. The work was more challenging than I could have imagined, but I really enjoyed interacting with the community. Two years later, I was promoted to detective and spent the next ten years in Criminal Investigations, three of those in the Special Victims Unit.

Saddened by a lot of what I saw and heard, it was still very rewarding to advocate for victims, particularly children and the elderly. My passion, however, was cold cases. I exhumed my first body only a few months into my tenure as a detective and if you can imagine, my superiors were rather stunned when a rookie detective found a missing person’s remains. One of my superiors would lovingly tease me afterwards, referring to me as “the mystic.”

Zodiac: Settling the ScoreIn Cold Blood

I worked on several cold cases including the 1959 murders of a family of four, and identified Richard Hickock and Perry Smith, the In Cold Blood killers immortalized by Truman Capote, as those responsible for the murders. In 2012, I obtained a court order and exhumed their bodies. Unfortunately, the DNA results were contaminated, but there was still physical evidence connecting the infamous men to the crime scene.

The Zodiac Killer

In 2014, while attending a cold case seminar, I stumbled upon the Zodiac case. I never intentionally researched the case; it kind of fell into my lap. As I was watching a presentation on the serial killer, it just hit me that I knew the identity of the Zodiac. I refer to this in my book as my “Newton’s Apple” moment. Researching the case, I was stunned how the pieces fell into place like slapping a jigsaw puzzle together on a lazy afternoon. This marked the second time in my career that I’d worked on a complex high-profile case in which this occurred. It’s a thrilling feeling, and one I hope to have again someday.

As to my theory of the case, it’s shockingly simple. I believe there’s strong circumstantial evidence that serial killer Dennis Rader, aka BTK, is the Zodiac killer. While all serial killers have certain traits in common, Rader and Zodiac have very specific but numerous similarities. Dennis Rader was serving in the United States Air Force during all of the Zodiac murders, except for the first murders that occurred in 1963. Rader was traveling a lot during this period and told an FBI agent after his arrest that this was the happiest time in his life because he was “free to kill.”

Zodiac/BTKEven by Rader’s own testimony, he was murdering more during this period than his years in Kansas, where he admitted to killing ten people. Rader also frequented prostitutes overseas, and admitted to the FBI agent that he would hail taxis and get as far away from the base as possible.

Under his coat he hid a gun, knife, and ropes. He also admitted to stalking women and fantasizing about killing them.

As for the first Zodiac murders, committed in 1963, Rader admitted he had fantasized about driving to California, kidnapping Annette Funicello, and dragging her to an abandoned house. Just shortly after theAnnette Funicello Beach Party trailer was released, a young couple was murdered about thirty minutes north of the film location. The couple was shot and dragged to an abandoned shack and the female victim’s bathing suit top was cut in the front.

I assert in the book that Rader must have been infuriated by seeing “his girl,” the mousketeer, scantily clad and with Frankie Avalon. This is most likely the reason Rader, acting as the Zodiac, initially killed couples. In his fantasy-driven mind he would have to eliminate Avalon to get to Funicello, and it’s no secret that Rader acted out his fantasies.

annette and frankie


Rader also admitted that he purchased a camera overseas and developed his pictures in an Air Force base darkroom. Rader, as BTK, took Polaroids of his crime scenes; Zodiac included specific details of his crime scenes in his letters, sometimes months after the murders occurred. I assert in my book that based on the facts, Zodiac was also photographing his crime scenes.

Side by side comparison of Zodiac and Rader…

  • They both used a taxi during the commission of a murder;
  • both typed and handwrote letters to police, the media, and family members;
  • both called police to report their murders and left the receivers off the hook;
  • both shockingly carried gun holsters, multiple firearms, precut ropes, and knives;
  • both used cryptic communications including ciphers and in particular linear name codes in their taunting letters;
  • both instructed the female victims to bind the male victims;
  • victims from both serial killings described their captors as nervous and “shaking,” victims in California and Kansas reported the killers specifically said, “I just want your wallet and your keys because I am wanted out of…;”
  • both wrote their page numbers the same, used identical abbreviations, wrote acronyms, and wrote the same salutations and valedictions;
  • both Zodiac and BTK adapted folk songs to poetry, frequented libraries, and referenced history and electronics.

BTK booBTK Zodiac symbols

There are so many similarities, in fact, I didn’t even include all of them in my book as it became impractical to do so.


Some have commented that Zodiac was not a “sexual” sadist or a strangler like BTK and, therefore, they’re not the same person. Zodiac, of course, talks about sadism at length in some of his letters. Zodiac describes his fantasies about torture and how he enjoys killing more than “getting his rocks off with a girl.” Zodiac also “choked” one of his victims and cut the bathing suit top of at least one of his female victims.

While the sexual overtones are more obvious in the BTK killings, a lot of it was only gleaned after Rader’s confession.  Rader’s modus operandi evolved over time due to experience, circumstance, and his ever-increasing need for BTK califexcitement. Just as Zodiac threatened at the end of his reign of terror to blowing up a busload of children, Rader admitted to police that he began following children at the end of his BTK activity. Rader also admitted in his journal that he killed for power, and this certainly fits Zodiac’s behavior.

BTK case

BTK acronymsSome have also commented that BTK was a “home invasion” killer while Zodiac shot his victims out in the open. There’s a simple explanation for this change in M.O. As Zodiac, Rader would have much less risk of being recognized as he was not a known member of the community. Rather, he was acting as a poacher and, therefore, not worried about being recognized. When Rader got married and settled down he was not as free to travel outside of his area because he was a known member of the community, particularly due to his being a deacon at his church. Burglarizing homes was really the only way he could keep his anonymity.

Otherwise, his behavior remained consistent to Zodiac’s: binding, stabbing, shooting, and exerting power over his victims. Zodiac and BTK’s signature is the same: the immense excitement over exerting power over and killing his victims.

Some have asserted the notion that Rader would have confessed to the Zodiac murders to obtain more media attention, but I believe there’s a logical explanation for why he hasn’t. When Rader was arrested, he was presented with overwhelming physical evidence, so he confessed. Rader, just as is common with other inmates, soon learned what his confession got him: loss of family, loss of his job, loss of his title, etc.

BTK and_signsRader soon took on more of his Rader/Christian persona, distancing himself from BTK. He speaks of this in an interview with the FBI on how he doesn’t like when the guards call him BTK. He also writes a lot about God and draws smiley faces. Rader, while obviously sociopathic, may still be protective of his family in a narcissistic manner and most likely wouldn’t want them to deal with further embarrassment.

Some have also proposed that Rader had an alibi because he was “stationed overseas” during some of Zodiac’s killings or letter writing. I have yet to see any evidence Zodiac piscesof a specific alibi on the specific dates, and Rader himself admits he traveled often during his time in the military. I have found several sources that not all military flights or personnel on board were logged and, in fact, some were intentionally avoided on covert missions.

Rader worked on radio equipment and often such airmen were brought on flights for this purpose.

Some have also questioned why potential DNA or fingerprint evidence has not been linked to Rader. It’s been my experience that when dealing with old cold cases that DNA is often “partial” and contaminated. It’s also been my experience that fingerprints can be palm prints, or not even belong to the suspect at all. Whether my theory will ever be proven or disproven remains a mystery at this time. But if men, let alone serial killers, can have that much in common, the similarities between Zodiac and Dennis Rader should be a study in and of itself.

Kim_Cold CaseTo dive deeper into Kim’s theory of the two cases, grab a copy of Zodiac, Settling the Score.

Connect with Kim on Twitter: @kimmcgath

Instagram: kimberlymcgath


www. kimberlymcgath.com or www.zodiacsettlingthescore.comKim_Cold Case2

She’s also a singer/songwriter. Check out Chills Down the Spine. This song, Where His Hat Used to Hang, is a beautiful tribute to fallen officers.

About Sue Coletta

Member of Mystery Writers of America, Sisters in Crime, and International Thriller Writers, Sue Coletta is the bestselling, award-winning author of psychological thrillers and mysteries. OOTG Flash Fiction Offensive magazine published her flash fiction and her short stories are published in numerous anthologies and collections. InSinC Quarterly featured her forensic articles about Radiocarbon Dating and Skeletal Differences. In 2017, Feedspot awarded her Murder Blog as one of the Top 50 Crime Blogs on the net. Sue's also the communications manager for Forensic Science and the Serial Killer Project. As a way to help fellow crime writers, Sue created a team of crime experts (detectives, coroners, police captains, etc.) and founded #ACrimeChat on Twitter. She's also a proud member of the Kill Zone, where she blogs every other Monday.


  1. I was watching the show cold cases files tonight..the newer show on Sling..Coincidentally , l watched Btk and then went back a few seasons and watched zodiac. I couldnt believe the similarities in the 2 cases..So i looked it up online to see if they’d ever been linked and bam. Here it is! Kim McGath..i believe you are on to something here. I’m no sleuth myself but even I saw the similarities just watching the cases on tv.

  2. Dennis Rader was stationed in Japan at the Tachikawa Air Base, until the summer of 1970, when his active duty service ended. The Zodiacs’ first confirmed murder (David Faraday & Betty Jensen) happened Dec 20th 1968. I suppose you could make the case that Rader was home on holiday leave during that time, but what about the other Zodiac murders that occurred while Rader was allegedly on base?

  3. The only problem I have with Rader as the zodiac is that rader kept records and things like that from victims no way would he have discarded them and assumed a new identity as a killer. While I agree that the similarities are there I think Rader is just BTK and zodiac is still a mystery. I would be happy to be proven wrong and I know one day the truth will come out. 😉

    • Sorry but a tid bit more zodiac refused to send pictures of his ” death machine ” because he knew it could be traced seriously don’t think he would have made the mistake of sending a floppy disc

    • You’re certainly entitled to your own opinion. Thanks for weighing in.

  4. Sue, you are not the 1st to see the conection of BTK to Zodiac
    when the BTK thang happened 05 -06 a TV reporter here in KC reported on it . think it was CBS KCTV5, every one watched thinking Zodiac would be solved . Cal. TV reported on their reports ,but a relative who said he hated Raider too, stated he was at an event during 2 of the attacks , L E even looked into it and the reporter retracted the story .

    have you seen this story about KC and Z

    • As much as I’d love to take credit, I didn’t see the connection. My guest did. I’ll let her know you commented to see if she has anything to add.

    • Interesting story. Do you know the name of the reporter? Thanks so much for sharing it. Relatives are certainly not the best alibi witnesses, and during my tenure, I was lied to often by family members trying to assist a loved one. Also, interesting this relative would recall such a thing after 30 years, unless it was a wedding or something of note.
      Ironically, Richard Hickock and Perry Smith were initially discounted as suspects in the Walker murders due to a faulty alibi, which I later disproved. Of course, I did not have access to what the officials have in the Zodiac case, but in my experience, even investigators can discount a suspect too quickly.
      Thanks again so much for the information. 🙂

    • Fascinating article about the satchel. Thanks so much Dave 🙂
      Kimberly McGath recently posted…Partners in Crime – Missing PersonsMy Profile

  5. I’m so glad you referred to this earlier post in your more recent one. This is fascinating!
    Staci Troilo recently posted…Introducing #Romance #Novella Laci & DelMy Profile

  6. The similarities in the handwriting are very interesting. Has anyone done handwriting analysis to compare Rader’s and the Zodiac’s handwriting?
    Ann Marie Ackermann recently posted…Alexandre Lacassagne: Founder of Forensic Ballistics?My Profile

  7. I’m just attonish with the similarities that Kim found. I had to read that book.

    Thanks, Ms. Sue for inviting her.

  8. Ms Coletta:

    Today I replied to your post on The Kill Zone. I would have said what am about to say, but after I posted my story, I don’t want it to be a case of “and then, after I climbed Mount Everest, I saved the world again by . . . ”

    But I do want to comment that my long-time writing partner, Jim Dobkins, a true crime writer. He wrote a book, My Boss Was the BTK Killer. He found a young woman who had worked as an assistant to Dennis Rader. She thoroughly believed that Rader had her pegged to be his victim.

    Dobkins’ first true crime book was a book club best killer, The Trunk Murders. The book was taken directly from the trial transcript of the trial of the accused and convicted 1930s “murderess,” Winnie Ruth Judd. (Jana Boomersbach also wrote about Winnie Ruth Judd. Her book in my opinion, is a vastly inferior work about the murders themselves. She concentrated more on Miss Judd.

    Coincidentally, I believe that Dobkins knows who in fact The Trunk Murders killer was. Dobkns also wrote books on Machine Kelly, whom he met way after the time that Kelly was, according to the FBI, dead ahd buried.

    Your theory about Dennis Rader being the Zodiac Killer intrigues me. I have to read your blog post again.

    I have signed up for your newsletter.

    It’s a pleasure to get to know your work through your blog and your TKZ post.

    • Please call me Sue. Ms. Coletta sounds so old. 🙂

      The story about your writing partner is fascinating, Jim. I was equally intrigued by Kim’s theory of the Zodiac case. Personally, I think she’s nailed it. Incidentally, she was instrumental in proving the identity of the In Cold Blood killers, too. Back then, she was just a rookie. But she has a gift of seeing connections where others don’t. I truly hope her theory is proven. It’ll be fun to see how this plays out.

      Looking forward to getting to you know you better, here and on TKZ.

    • Wow. I just read your story on TKZ. I’m speechless, which doesn’t happen often.

    • Wow Jim, you have some fascinating friends. I would love to speak to Mr. Dobkins. Here is my email: coldcaseconsults@aol.com. Thanks so much for your post. 🙂
      Kimberly McGath recently posted…Partners in Crime – Missing PersonsMy Profile

  9. What I don’t understand is that if Dennis Rader was 18 at the time of the California killings, wouldn’t he be too young to be the Zodiac Killer? The Zodiac was thought to have been in his thirties or forties. Wasn’t Rader too young to be the killer? Thanks

    • True crime is filled with teenage murderers. Eighteen is old enough to kill. Besides, the California murders were the first ones. They didn’t “profile” the killer till later, I don’t think. To be safe, I’ll ask Kim to respond. She’ll be able to answer your question way better than I can.

    • Hi there and what an excellent question. Authorities of course have to go on information provided by eye witnesses. Unfortunately that information can be misleading and often derail an investigation. For example in one of the BTK cases the sketch of the suspect was actually a sketch of a neighbor who had nothing to do with the murder. Also if you look at the two Composites in the Zodiac case there’s no way they’re the same person. There are many cases in which witnesses have even confused the gender or the race of a suspect; height and age are often “guestimates.”
      There are no eyewitnesses to that first murder when the murderer would have been younger. There are also indications that murder was committed by a juvenile such as a failed arson attempt. (Revealing inexperience)
      BTK was also known to disguise himself in various ways and zodiac even says in his letters that he does not look like he did in the notorious San Francisco sketch.
      I hope that answers your question and thanks so much for posing it.
      All the best,
      Kimberly McGath recently posted…Join me live on the air!My Profile

  10. How exciting! I love this sort of thing. I binge watch 20/20 and 48 Hours and am currently reading everything Ann Rule ever wrote. I do agree, this sounds like a match…and a great premise for a book describing the “two killers who were actually one” reign of terror!

  11. I’m so grateful to everyone who works to put these people behind bars… Thank you both for sharing this fascinating post!

  12. A very intense post. So much information that makes the mind spin. I am enthralled by the people who devote their lives to this type of research.

  13. Great read and very interesting!
    Joycelin Leahy recently posted…The Dome Camper – PhotographyMy Profile

  14. This is really interesting, Kim & Sue. I don’t know very much about these two cases – Zodiac and BTK – but I have a bit of experience in recognizing evidence.

    There’s an evidentiary rule of law in Commonwealth countries (not sure if it applies in the States, but it should) called similar fact evidence or similar fact principle. There’s no set number of points but when the prosecution can show that a person is responsible for a particular crime, or series of crimes like Dennis Rader is guilty of in the BTK case, then his documented actions (MO) can be admitted as evidence against him in other cases like the Zodiac murders.

    The principle goes like this – when the probative value of the evidence outweighs its potential prejudice, thereby justifying its reception, then it can be admitted as evidence and left to stand before a jury to assess its weight. The whole point is to prove a nexus or connection via MO to other crimes, therefore the assumption can be made that the accused is guilty of all the crimes.

    Kim, you’ve identified so many points of similar fact here that I’d be amazed if the two cases weren’t related. Good job & best wishes for your book!

  15. Hey Kim. Wow, intriguing read. Thanks for sharing this here and I’ll check out your book!
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  16. This is truly fascinating. Wonderful guest. I haven’t studied the cases but recall them being in the news forever. There has to be so much more that modern science reveal. It’s interesting to me that we watch so many serial killers on TV dramas like Criminal Minds, NCIS, Dexter , and so on, but it’s been awhile since there has been any notable one in the news (unless I’ve been too preoccupied to notice). Kinda makes you double think on the claims that TV shows like those are a bad influence. To the contrary, the broadcasting of contemporary forensics likely discourages would-be killers. (Even if much of it is highly inaccurate.)

  17. Brendon Hartwig

    Stunning article, perfect balance of a brilliant guest, a corking write-up and fab visuals….thank you, really enjoyed reading!

  18. This is absolutely fascinating!! And those side-by-side comparisons certainly do give one serious ‘food for thought.’ Thanks very much, both. Makes me wonder…

  19. Excellent article!!!!

  20. Outstanding guest, and wonderful theories. I was a boy in Nevada at the time of Zodiac, and it was on every adult’s lips. He did come into the Tahoe area at one time. It seems so long ago now. How old was Rader in 1963?

    • Hi there! Dennis Rader was 18 in 1963 and had just graduated high school. Thanks so much for your comment and your question and I hope you have a lovely weekend. All the best, Kim

      • Hi Kim, have you thought about interviewing Dennis Rader? Also, didn’t he admit to killing for 30+ plus years when he was arrested? I would think that proves your theory right there.

      • That certainly makes it possible. Perhaps modern science could lend a hand. There were so many things they could’nt do in the 60s.

        • Exactly, Craig. And by his own admission, Rader was killing for something like 30 years, give or take. I don’t remember when BTK was arrested, do you?

          • I don’t, but I thought it was this century. Maybe I’m confused with Green River. Did you ever read that book by Hare, about psychopaths? He interviewed a bunch of these guys.

            You’re making some wonderful contacts in your genre. Sounds like you’re doing very well with Married. (Joking, just joking. I read your bit on FB.)
            Craig recently posted…Just an updateMy Profile

            • LOL Funny guy!

              Yup, my detective antennae is alive and well. I can spot a cop a mile away, then I swoop in. 🙂

              I thought Rader was arrested this century, too.

      • Rader was arrested out in Kansas in 2005. Most of his “BTK activity was from 1974 to 1991. He began corresponding with police again in 2005 which led to his arrest that year.

        Wow Sue, you have the smartest and best readers/bloggers!!!
        Kimberly McGath recently posted…Welcome to my blog!My Profile

        • Thanks for “settling the score” on when he was arrested. I was thinking 2005, but I wasn’t sure.

          I do have the best community, and now you’re part of it. Yay!

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