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Forensic Linguistics: The Oft-Overlooked Relationship Between Language and Courtroom

— August 18, 2021

The winds of change are blowing and the growing demand for forensic linguists is a harbinger of fundamental alterations in the world of law.

Only a few people realize that one of the fastest growing fields in the forensic world has little to do with crime evidence or blood. Language – just a punctuation mark, dare I say – can give us away in countless ways that exceed our wildest imagination. The development of forensic linguistics hit a peak in the 2000s, thereby spreading all over the world. Not only did the blistering pace of this process entail the establishment of various professional associations (such as the International Association of Forensic Linguistics), but also a growing demand for scientific language analysis. In layman’s terms, forensic linguistics can be divided into two major areas, namely spoken language (embracing acoustic qualities) as well as written language. 

Interestingly, forensic linguists focus not so much on WHAT was said but HOW it was said – factors such as pronunciation, dialect or speed of speech carry much more weight than most of us realize. The phrase “forensic linguistics” was coined in the 1960s by a professor of linguistics, Jan Svartvik. More importantly, Svartvik was heavily involved in one of the first major cases in which forensic linguistics was directly used to achieve justice (the case of Timothy Evans, wrongfully accused of murdering his wife and baby daughter.) That being said, forensic linguistics can be used in examining non-violent crimes as well, such as plagiarism. 

While discussing the relationship between forensic linguistics and plagiarism one cannot help but mention the case of Nancy K. Stouffer and the court battle she was waging against J.K. Rowling. What is more, forensic linguistics is widely used in judicial processes as well. By employing a wide array of linguistic tactics, the police (or lawyers) can elicit specific responses from the suspects (with “wh”-questions allowing for elaboration and yes-no questions limiting the response.) Nevertheless, maintaining that forensic linguistics is used only to find the guilty would be nothing short of a gross oversimplification. This well-established, independent field of study comes in useful while protecting the innocent as well (the “Miranda Warning” in the United States.) All in all, forensic linguistics can be said to serve justice in the multifaceted world of law.

Analysis of an idiolect: a key component of author identification

In the vast majority of cases, forensic linguistics is used in order to identify the authorship, which in turn relies on analysis of one’s idiolect. At no time should an idiolect be confused with a dialect, since the former is invariably unique at the individual level. That being said, a variation of an idiolect can be noticed within the confines of a particular environment, such as an ecolect (i.e. unique to a household) or a familiolect (i.e. unique to a family.) Providing evidence with regard to one’s idiolect is oftentimes nothing short of infeasible, as language acquisition spans over one’s lifetime. Consequently, an individual’s use of language is susceptible to variation brought about by other speakers or even the media.

Books and a spiral-bound notebook of notes on a desk; image by Chloestrong, via
Books and a spiral-bound notebook of notes on a desk; image by Chloestrong, via

Author identification can be approached from a more statistical angle as well. Authorship measures adopted by analysts range from world length average, article frequency to the occurrence of hapax legomena. Hapax legomenon – a transliteration of a Greek phrase meaning “being said once”, represents unique words in a text. According to John Olsson, a world-renowned forensic linguist, language profiling can be also divided into masculine (distant) and feminine (being more discursive) use of language. The aforementioned theory goes hand in hand with the concept of a linguistic fingerprint. Just as a fingerprint – a detailed impression unique to an individual, one’s use of language may be perceived as a long-term marker of their identity. 

The argument against linguistic fingerprinting: intra-author variations

Evidence derived from forensic linguistics has more power to eliminate someone as a suspect rather than prove them guilty. Nevertheless, two texts written by one author may actually stand in stark contrast to one another. Linguistic knowledge, applied in the context of law, takes into account variations such as: genre, adopting a disguise, span of time or a text type (there is obviously a world of difference between personal letters and academic papers, even if they are written by the same author.) 

Forensic stylistics – how is it used in legal proceedings?

Forensic stylistics plays an unparalleled role in scientific analysis, especially when it comes to the determination of authorship. Consequently, determination of authorship enables forensic linguists to identify plagiarism, as it was with Helen Keller’s short story “The Frost King” in 1892 (further reading highly recommended.) 

Another world-renowned case worth bringing up is the example of Theodore Kaczynski and his identification as the author of the so-called “Unabomber Manifesto”. Analysis of lexical items and phrases in text messages also came in useful while convicting Jenny Nicholl’s murderer, David Hodgson. As of July 2021, Jenny’s body has not been found. However, the analysis of the timeframe and Nicholl’s usual texting style enabled forensic linguists to serve justice for her. 


The winds of change are blowing and the growing demand for forensic linguists is a harbinger of fundamental alterations in the world of law. The acknowledgement of this field as a science marked a stirring of a new chapter in crime investigations. Such a change in our collective perception should act as a catalyst for even more far-reaching developments in the provision of linguistic evidence. Moreover, there is little prospect of forensic linguistics becoming a relic of a bygone age within a span of a few decades. Throughout recent years, this field has gained immeasurable impetus, serving as a colloquial eye-opener in countless areas, such as law or psychology. 

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