Retired FBI agent James Fitzgerald — an expert in forensic linguistics who was key in ferreting out Ted Kaczynski as the Unabomber and who has been an advisor on Criminal Minds and Sleepy Hollow — has been working on the JonBenét Ramsey murder case since the six-year-old’s body was found in her family’s Boulder, Colorado home the day after Christmas in 1996.

Fitzgerald and half a dozen fellow investigators spent months re-investigating the Ramsey case earlier this year. Their findings, and most notably, their potentially explosive conclusion, was filmed for CBS’s two-night, four-hour limited series The Case Of: JonBenét Ramsey, which premieres Sept. 18.

Fitzgerald’s specific area of expertise in the Ramsey case is the ransom note, and he talked to Yahoo TV about its significance in the crime, how he interpreted it, which clues revealed the most about the person — or people — involved in JonBenét’s murder, and, yes, how he and his cohorts will end the CBS series by naming the person they believe killed JonBenét Ramsey, as well as those who may have helped that individual get away with murder… until now?

What’s the history of your involvement with the JonBenét investigation?

I was involved about 19 ½ years ago as an FBI profiler and a fledgling forensic linguist when the Boulder PD investigators came to Quantico. That was my initiation, if you will, with this case. They came back at least one or two other times, and I was certainly in touch with them over the phone. My role then was as a profiler, but they knew of my success in the Unabomber case, looking at the manifesto and the writings of Ted Kaczynski. They asked me to focus on the ransom note, the three-page note. That’s kind of where I ran with it. We had other profilers running with the crime scene and the behavior involved, which I participated in, too, but I was the main guy in the FBI looking at the note. That was then. When I came back into it with this team, a few months ago when we started filming, I re-assumed that role.

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Forensic linguistics had played an invaluable role in the Unabomber case, right?

Yes, I learned a lot about language analysis, language assessment, and how people do communicate similarly within themselves over the course of time. If they wrote something 10 years ago, you’re going to see some of those writing features come to play in present or future writings. I took that with me to the Ramsey investigation and said, “We’re going to get some [samples] with [JonBenét’s parents], Patsy and John, and any other suspect you have in the case.” Not just handwriting… I said, “Handwriting analysis is great, but it’s not what I do. Linguistic analysis is more about the content — the context, style, which includes punctuation and spelling and all these other features.” I was the first one to suggest that on the case. We proceeded from that point on.

At that time, when you were investigating the ransom note, what things struck you as unusual or interesting about it?

The first thing was the very first two words, which said: “Listen carefully!” This is a written communication meant to be visually comprehended, but here someone is using an audible reference. Right away, I said, “This doesn’t even make sense.” Grammatically it’s correct, the words were spelled right, but it was an unusual way to begin an alleged ransom communication. This whole “foreign faction” thing and whether someone is a foreigner or not… do you consider yourself a foreigner when you’re in someone else’s country? Would you give that information away to the police? Right after the word “foreign,” they misspelled two words: “business” and “possession.” I believe both words were misspelled on purpose, because they both had to do with the double consonant “s.” If you’re going to misspell one word, you’re probably going to, almost by accident, get the other word right. Right then, I knew we had someone pretending to be someone other than who they really are. Within the first three sentences, quite frankly, I was convinced that this was not an authentic kidnapper. It was not an authentic crime syndicate or terrorist group or anything like that. This was someone doing his or her best to make themselves appear to be one of those entities, but it was clear that that was not the case.

What about the amount the alleged kidnapper asked for, $118,000? The amount seems so oddly specific, and it seems like such a low amount for the ransom of a child from a wealthy family.

You’re absolutely right, on both counts. We found out later the Ramseys could have easily come up with a million dollars that next day. They had the wherewithal, financially, to do that. It wasn’t a coincidence that the amount, $118,000, was chosen, because that happened to be the [amount of the] bonus that John Ramsey was awarded that year at his software company. I believe that was a red herring by the author to make it look like, in fact, it was an inside job of some sort. What I think the picture they completed was, that it was truly an inside job — very much inside, in terms of that particular feature right there.

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What was your conclusion at that time, about the note and what it might mean in terms of who was involved with the murder?

To be a profiler, to be a linguist, when you’re studying these types of crimes and cases, you have to be a student of history, too. Ever since I was a young kid, I read about the Lindbergh kidnapping and the few other for-profit, stranger-related, kidnappings in the U.S. There’s been very few of them. I knew the Lindbergh kidnapping note was maybe 60 or 70 words. Other notes over the years are 50, 60 words, some even much shorter. All of a sudden, measuring nothing else at this point except quantitatively, we have about 385 words in the [Ramsey] ransom note. Way too much information. Way too much evidence. It’s clear that all of it could have been written in about three sentences. “We have your daughter. We want $118,000 or we’ll kill her. We’ll call tomorrow.” That’s all that was needed. This thing, instead, read like a Stephen King novelette, with people being beheaded and all kinds of nasty things happening to people. The person who was writing this was truly out of his or her element, in terms of trying to be a real criminal or a real kidnapper.

One of the things you can do via forensic linguistics is try to focus in on the age or the gender of the writer of a note, maybe where they’re from, the significance of certain phrases that they use. Was there anything like that in that note?

Yeah, in forensic linguistics there is an aspect to it of linguistic profiling. We look for demographics, we look for personality traits, and yes, in some cases, depending on the style of the author, you can actually come into an age bracket, maybe within 10 years. You can actually come into gender. You can actually relate to issues such as nativeness — are they native English speakers or not, or natives of any language. That is what we did with this particular letter. You’ll see it in [The Case Of], that I spend a solid 10-15 minutes breaking the letter down, almost sentence by sentence, and also painting a picture of what kind of a person may have done this. I did actually say, “We linguists, we’re very conservative when we render opinions like this.” There are a lot of mitigating factors with language. Gender, of course, is kind of on a continuum. It’s not just black and white, man/woman. We’re conscious of that when rendering decisions about gender or the sex of the author. In this particular case, what I wound up saying was that [the note] has a maternalistic sound to it. If you want to make that into female, you can certainly do that. There’s about five or six examples coming out on the show, which almost comes across as a mother talking to one of her children, so maybe that, subconsciously, was in fact happening here.

When you look at the note now, as you have done more recently, did anything strike you differently than it did 20 years ago?

No, not really. I was not an official linguist when I first looked at the note in the late ‘90s, but I went back and got my second master’s degree at Georgetown University, this one in the science of linguistics. I can now look at the language features from more of a scientific, quantifiable perspective, and compare them to other letters and other corpora. I just have more of a scientific approach to what it is I do now. [But] I think I pretty much broke down the note pretty well back then, in terms of the evidentiary features of it and what we needed to look for, if we had some known writings from any suspect. We put some of that together on the show Sunday and Monday night.

You created the CTAD, which is a database of all of the words that should be looked at, if you are profiling a note or a letter?

You’re in the right church. In the FBI, yes, I created the CTAD: the Communicated Threat Assessment Database. Essentially, for the first time in the FBI, we had one specific location where we would have digital versions of every kind of threatening or criminally oriented or problematic communication that the FBI would be handling: bank robbery notes, the very rare ransom letters of kidnappings, many threats, many extortions, much harassment and stalking. I built that up from zero letters to thousands by the time I retired. Now it’s approaching half a million different types of communications — emails, blog entries, old school letters — that are all in there. This wasn’t around when the Ramsey case started, but I made sure that [ransom note] was included in it. A ransom letter like this, which really was never a ransom letter — it was part of a staged crime scene — is now in there, and it can be assessed and compared to other types of communications.

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How different is the crime-solving technology you had to work with in re-investigating this case, versus where it was 20 years ago? Is it dramatically better?

Yes, it is. The internet has certainly helped in many ways, and various corpora, bodies of documents that can be digitally searched. I think if a linguist would have been brought into the Ramsey case within days — and even with the then relatively new thing called the internet, some searches could have been done — I think we could have convinced the police, “Let’s ask them this question, let’s ask them that question.” Perhaps the matter could have been resolved back then. Yeah, technology really, with the ways in which we can digitize and search these various types of criminally-oriented communications and compare them to other existing ones out there, makes a real big difference and really speeds up the kind of work forensic linguists do.

In the trailer for The Case Of, you say, “This little girl’s homicide to this date has not been resolved. In my opinion, I think we can change that right now.” In the end, were you able to do that with this re-investigation?

The answer is yes, with a caveat that putting handcuffs on someone, in my estimation, would be the ultimate end, and, of course, convicting that person in a court of law. Whether that happens or not is up to other people above and beyond the seven experts who worked on this show. I feel safe and very confident to say that when the seven of us sat around the table in the final day of shooting, and we put all of our information together — all the evidence we learned, some old, some brand new, some reinforced by newer technologies and science — we feel very firm and very much convinced [about] who it is we’re going to name at the end.

You are going to name who you think committed this crime?

Yes.

That’s pretty amazing, after all this time.

Well, we have seven of the best experts in the country, if not the world, working this case — for the second time in some cases. We had the archival information, the historical information, and we also had all the new evidence that was gathered over the years and even in the last few months, in preparation for this show. If it existed out there in the way of evidence, either inculpatory or exculpatory, we had it. We feel very firm in rendering an opinion within the last 15 minutes of the show.

Why is it so important to provide closure at this point? Some people may say, “It’s 20 years later, why are so many resources being devoted to this particular cold case?” Does it maybe deter other crimes from happening, if a case is solved this far past when it occurred?

If we as a species, as human beings, can’t protect the youngest and the most innocent among us, then we fail. Short of protecting them, when something bad does happen to them, death or an assault of some sort, then we owe it to that victim, and we owe it to every other child or innocent victim out there, to bring justice. Of all people, a six-year-old girl who had a lot to live for and did absolutely nothing wrong — I mean, no six-year-old could bring murder upon herself — she was, in fact, murdered. For these almost 20 years, there’s been a person out there who knows exactly what happened and maybe some other people who did some things to cover the tracks there. We’re going to put it out there and make it public. It depends on how you define whether justice is served or not, but this is going to be the closest we can get, or anyone has gotten as far as I’m concerned, in the conclusion of Monday night’s show.

The Case Of: JonBenét Ramsey premieres Sept. 18 at 8:30 p.m. on CBS, and concludes Sept. 19 at 9 p.m.