Forensic linguistics: the way of speaking and writing gives us away

In 2002 the prosecutor overthrew Stuart Campbell’s alibi in the murder of his niece Danielle Jones, in Essex (England). The experts proved that he was the murderer and not the victim, as he had led to believe. The key tocrimeit was in some messages the uncle sent from Danielle’s cell phone. Analysis of the text undoubtedly revealed that the style was typical of the suspect, who never imagined that a hundred characters could put him behind bars.

Campbell was also probably unaware thatthe structure and content of the sentences we use on a daily basis in conversations are almost unique. Or that the punctuation and grammar of an anonymous message may be enough to determine the age, gender, and geographic location of its author. But the truth is thatforensic linguistsdeal with these differences on a daily basisthe use of words, which over the last decade have allowedunequivocally identify terrorists and criminals of all kinds.

It is a fact that there is a distinctive way in which each individual encodes and decodes language and expresses himself with his own linguistic “marks”. And that no two people use language in exactly the same way. Experts such as James Fitzgerald, an FBI investigator, have verified this after several years working on the analysis and identification ofanonymous documents.

“Human beings are prisoners of their own language,” says the linguistDon Foster, who has collaborated with Fitzgerald on several cases. And he adds: “That is why the scientific analysis of a text can reveal data as clear as fingerprints or DNA.” It was precisely this technique that allowed Fitzgerald and Foster to solve a key case in the history of the United States: that of the terrorist FC, better known asUnabomber, who launched a crusade against technological progress by sendingletters-bombto different parts of the country for 18 years.

Tell me what you write and …

After a long time sowing panic,Unabomber wrote a manuscript of more than 100 pages threatening to blow up a plane if it was not published in the press. The authorities responded to his request, hoping that the text would lead them to a suspect. In 1996 Ted Kaczynski was arrested, alerted by his brother after reading the manuscript. The FBI searched his home for all kinds of texts and letters. Comparison of these documents with the threatening dossier confirmed that they were the work of the same person, a proof so solid that it allowed him to be convicted. What is more curious, Foster reached such unusual conclusions as that Kaczynski’s favorite magazines wereScientific AmericanYThe Saturday Review, who was influenced by the writings of the Polish Joseph Conrad or who identified himself with an object, wood.

But where is the catch? Forensic linguists compare writings with available text databases in search oflinguistic habitsSimilar. This includes identifying thevocabulary, slang, slang, regionalisms, and even punctuation. Without underestimating any detail of the document format and the physical medium in which it is found. If the communication is oral, for example in arecording, you must also take into account the rhythm, phonetics, pauses, intonation or the separation between words and letters.

Subliminal messages

Delving into the use of language, linguists have found, for example, that thetruthfulness of a storyit is greater the more complete are the sensory details that it incorporates. Or that the disappointment is transferred to the language in the use of preludes longer than usual. They are what some experts callsubliminal messages or thoughprints, this is,thought tracksthat continually appear when we communicate. To this must be added that the use of new forms of communication, such as theemailo lamobile phone, is giving to talk among forensics. Linguist Tim Grant and coroner Kim Brake of the University of Leicester launched the first forensic study focusing on theSMS messages. “Given that these are a new form of communication and, at the same time, an especially informal way of using language, the writer is not expected to follow linguistic convections,” Grant clarifies. “This freedom – he adds – gives rise to significant differences in the style that can be used to identify its author.” In addition, experts will study how the SMS they receive from their friendly circle influences a subject’s style.

Another of the tasks of linguistic and legal specialists is to analyze the framework of thelanguage used in interrogations and confessions. Scientists also have sophisticated techniques for the analysis of imitation in theCompanyand the detection of texts written for criminal purposes, such asfake suicide letters. They are even capable of creating linguistic profiles and identifying the interlocutors of a conversation from a voice recording.

Against the vice of plagiarism

When it comes to judging whether or not a text is aplagiarism, forensic linguistics also has a lot to contribute. Its conclusions are key in court. But what makes a text unique and original? What defines your idiosyncrasy? And above all, what degree of similarity do two or more texts have to reflect to consider that they have been plagiarized? From her office in the Forensic Linguistics Laboratory (ForensicLab), at Pompeu Fabra University (Barcelona), researcher María Teresa Turell tries to answer these questions. His experience in this field helped him, among other things, to participate in the case of the alleged plagiarism of Camilo José Cela to Carmen Formoso. His laboratory established that it was not a plagiarism of the text, in any case of ideas.

Turell also intervened in the scandal of the television presenter Ana Rosa Quintana, who in her book Sabor a hiel appropriated entire paragraphs of Ángeles Mastretta (Big eyed women), by Colleen MacCullough (The bird sings to death) and Danielle Steele (Family album). Although in these cases it is always possible to resort to the irony of John Milton, who in the seventeenth century stated that “copying from one is plagiarism, copying from two is research.”