“Yes,” Kaplan spoke up. “We understand you were supposed to meet with him.”

“Tuesday afternoon. It didn’t happen. I got held up at a conference in D.C., sponsored by the Forensic Linguistics Institute.”

“A conference for linguists,” Rainie muttered. “That had to be a blast.”

“Actually it was quite fascinating,” Ennunzio told her. “We had a special presentation on the anthrax envelopes sent to Senator Tom Daschle and Tom Brokaw. Were the envelopes sent by someone whose first language was English or Arabic? It’s an extremely interesting analysis.”

Rainie startled, intrigued in spite of herself. “Which one was it?”

“Almost certainly a native English speaker trying to impersonate an Arabic speaker. We call that ‘trick mail,’ when the sender attempts certain devices to mislead the receiver. In this case, the definitive evidence is the seemingly random mix of uppercase and lowercase letters throughout the text on the envelope, as well as a mixing of large and small caps. While this is meant to appear sloppy and childlike-someone uncomfortable with proper English syntax-in fact, it indicates someone so comfortable with the Roman alphabet he can manipulate it at will. Otherwise, it would be difficult to construct such a varied combination of letter styles. And while the messages in the two envelopes are short and filled with misspellings, this is again an attempt to deceive. Short missives actually involve a very concise use of the English language and are consistent with someone of higher, not lower, education. All in all, it was a first-rate presentation.”

“Okay,” Rainie said. She looked at Kaplan helplessly.

“So you didn’t actually see Special Agent McCormack on Tuesday?” Kaplan asked.

“No.”

“But you had spoken to him before?”

“When Special Agent McCormack arrived at the National Academy, he stopped by my office asking if I would have time to consult on an old homicide case. He had copies of some letters that had been sent to the editor, and he wanted any information on them I could provide.”

“Did he give you copies of the letters?” Quincy spoke up.

“He gave me what he had. Unfortunately the GBI was only able to recover the original document for the last letter, and frankly, there’s not much I can do with published versions. The newspapers sanitize too much.”

“You wanted to see if the guy also mixed small and large caps?” Rainie asked.

“Something like that. Look, I’ll tell you the same thing I told Special Agent McCormack. Forensic linguistics is a broad field. As an expert, I’m trained to study language, syntax, spelling, grammar. I don’t analyze penmanship per se-you need a handwriting expert for that-but how a document is prepared and presented provides context for my own analysis, so it is relevant. Now, within the field, we all have our own domains. Some linguists pride themselves on a sort of forensic profiling-you give them a document, and they can tell you the probable race, gender, age, education, and street address of who wrote it. I can do that to a certain degree, but my own subspecialty is authorship. You give me two samples of text and I can tell you if the person who wrote the threatening letter is the same person who wrote that second note to his mom.”

“How do you do that?” Rainie quizzed him.

“In part, I look at format. Mostly, however, I’m looking at word choice, sentence structure, and repeated errors or phrases. Everyone has certain expressions they favor, and these phrases have a tendency to appear over and over again in their writings. Are you familiar with the cartoon sitcom The Simpsons?”

Rainie nodded.

“All right, if you were the chief of police in Springfield and you received a ransom note including repeated uses of the expression ‘D’oh!,’ you’d probably want to start your investigation with Homer Simpson. If, on the other hand, the letter contained the phrase ‘Eat my shorts,’ you’d be better off looking at the younger Simpson, Bart. All people have phrases they like to use. When writing text, they are even more likely to repeat these catchphrases. The same goes for grammatical mistakes and spelling errors.”

“And in the case of the Eco-Killer?” Quincy spoke up again.

“Not enough data points. Special Agent McCormack presented me with three copies and one original. With only one original, I can’t compare penmanship, ink, or paper choice. In terms of content, all four letters contain the exact same message: ‘Clock ticking… planet dying… animals weeping… rivers screaming. Can’t you hear it? Heat kills…’ Frankly, to compare authorship, I need additional material, say another letter you believe may have been written by the suspect, or a longer document. Are you familiar with Ted Kaczynski?”

“The Unabomber? Of course.”

“That case was largely broken on the writings of Mr. Kaczynski. Not only did we have the writing on the packages he used to mail out his bombs, but we also had several notes he included in the packages, many letters he wrote to the press, and finally the manifesto he demanded be run in the papers. Even then, it wasn’t a forensic linguist who made the connections, but Kaczynski’s own brother. He recognized parts of the manifesto from his brother’s letters to him. Without such an extensive amount of material to analyze, who knows if we ever would have identified the Unabomber?”

“But this guy hasn’t given the police much to work with,” Rainie said. “Isn’t that unusual? I mean, according to your own example, once these guys get talking, they have a lot to say. But this guy is implying he’s earnest about the environment, while on the other hand, he’s pretty quiet on the subject.”

“That is actually the one thing that jumped out at me,” Ennunzio said, his gaze going to Quincy. “This is getting more into your domain than mine, but four short, identical messages are unusual. Once a killer makes contact with the press, or someone in authority, generally the communication becomes more expansive. I was a little surprised that by the last letter to the editor, at least, the message didn’t include more.”

Quincy nodded. “Communication by a killer with either the press or an officer in charge of the investigation is almost always about power. Sending letters and watching those messages be retold by the media gives certain subjects the same kind of vicarious thrill other killers experience when revisiting the scene of the crime or handling a souvenir from one of their victims. Killers will generally start small-an initial note or phone call-but once they know they have everyone’s attention, the communication becomes about boasting, bragging, and constantly reasserting their sense of control. It’s all part of their ego trip. This message…” Quincy frowned. “It’s different.”

“He distances himself from the act,” Ennunzio said. “Notice the phrase, ‘heat kills.’ Not that he kills, that heat kills. It’s as if he has nothing to do with it.”

“Yet the message is filled with short phrases, which you said earlier indicates a higher level of intelligence.”

“He’s smart, but guilty,” Ennunzio told them. “He doesn’t want to kill, but feels driven to do it, and thus seeks to lay the blame elsewhere. Maybe that’s why he hasn’t written more. For him, the letters aren’t about establishing power, but seeking absolution.”

“There’s another possibility,” Quincy said shortly. “Berkowitz also wrote extensively to the press in an attempt to explain his crimes. Berkowitz, however, suffered from mental illness; he falls into a different category from the organized killer. Now, people suffering from some kind of mental incapacity such as delusions or schizophrenia-”

“Often repeat a phrase,” Ennunzio filled in. “You also see that in stroke victims or people with brain tumors. They’ll have anything from a word to a mantra they repeat over and over again.”

“You’re saying this guy is insane?” Rainie spoke up sharply.