Forensic linguistics

Forensic linguistics, legal linguistics, or language and the law, is the application of linguistic knowledge, methods and insights to the forensic context of law, language, crime investigation, trial, and judicial procedure. It is a branch of applied linguistics.

There are principally three areas of application for linguists working in forensic contexts:[1]

The discipline of forensic linguistics is not homogenous; it involves a range of experts and researchers in different areas of the field.


The phrase forensic linguistics first appeared in 1968 when Jan Svartvik, a professor of linguistics, used it in an analysis of statements by Timothy John Evans.[2]

During the early days of forensic linguistics in the United Kingdom, the legal defense for many criminal cases questioned the authenticity of police statements. At the time, customary police procedure for taking suspects' statements dictated that it be in a specific format, rather than in the suspect's own words. Statements by witnesses are very seldom made in a coherent or orderly fashion, with speculation and backtracking done out loud. The delivery is often too fast-paced, causing important details to be left out.

Early work of forensic linguistics in the United States concerned the rights of individuals with regard to understanding their Miranda rights during the interrogation process. An early application of forensic linguistics in the United States was related to the status of trademarks as words or phrases in the language. One of the bigger cases involved fastfood giant McDonald's claiming that it had originated the process of attaching unprotected words to the 'Mc' prefix (referred to as McWords) and was unhappy with Quality Inns International's intention of opening a chain of economy hotels to be called 'McSleep.'[3]

In the 1980s, Australian linguists discussed the application of linguistics and sociolinguistics to legal issues. They discovered that a phrase such as ' the same language ' is open to interpretation. Aboriginal people have their own understanding and use of 'English', something that is not always appreciated by speakers of the dominant version of English, i.e., 'white English'. The Aboriginal people also bring their own culturally based, interactional styles to the interview.

Areas of study

The range of topics within forensic linguistics is diverse, but research occurs in the following areas:

The language of legal texts

The study of the language of legal texts encompasses a wide range of forensic texts. That includes the study of text types and forms of analysis. Any text or item of spoken language can potentially be a forensic text when it is used in a legal or criminal context.[2] This includes analysing the linguistics of documents as diverse as Acts of Parliament (or other law-making body), private wills, court judgements and summonses and the statutes of other bodies, such as States and government departments. One important area is that of the transformative effect of Norman French and Ecclesiastic Latin on the development of the English common law, and the evolution of the legal specifics associated with it. It can also refer to the ongoing attempts at making legal language more comprehensible to laypeople.

The language of legal processes

Among other things, this area examines language as it is used in cross-examination, evidence presentation, judge's direction, police cautions, police testimonies in court, summing up to a jury, interview techniques, the questioning process in court and in other areas such as police interviews.

Forensic text types

Emergency call

In an emergency call, the recipient or emergency operator's ability to extract primarily linguistic information in threatening situations and to come up with the required response in a timely manner is crucial to the successful completion of the call. Intonational emphasis, voice pitch and the extent to which there is cooperation between the caller and the recipient at any one time are also very important in analysing an emergency call. Full cooperation includes frank and timely responses.

Urgency plays a role in emergency calls, so hesitations, signs of evasiveness, and incomplete or overly short answers indicate that the caller might be making a false or hoax call. A genuine call has distinctive interlocking and slight overlap of turns. The recipient trusts the caller to provide accurate information and the caller trusts the recipient to ask only pertinent questions. If the caller uses a rising pitch at the end of every turn, it might represent a lack of commitment; the recipient's use of a rising pitch indicates doubt or desire for clarification. The call ideally moves from nil knowledge on the part of the recipient to a maximum amount of knowledge in a minimum possible period of time. This makes the emergency call unlike any other kind of service encounter.[2]

Ransom demands or other threat communication

Threat is a counterpart of a promise and is an important feature in a ransom demand. Ransom demands are also examined to identify between genuine and false threats. An example of a ransom note analysis can be seen in the case of the Lindbergh kidnapping, where the first ransom note (sometimes referred to as the Nursery Note) stated: "We warn you for making anyding public or for notify the Polise the child is in gut care.[sic]".[4] From the sentence, the kidnapper makes the claim that the child is in good hands but to make such a claim, the note would have to be written before the perpetrator enters the premises. Therefore, the claim is false (at the time of writing) since the kidnapper had not even encountered the child when he wrote the note.[5]

Kidnappers may write statements that later end up being true, such as "your child is being held in a private location" being written ahead of time.

Suicide letters

A suicide note is typically brief, concise and highly propositional with a degree of evasiveness.[2] A credible suicide letter must be making a definite unequivocal proposition in a situational context. The proposition of genuine suicide is thematic, directed to the addressee (or addressees) and relevant to the relationship between them. Suicide notes generally have sentences alluding to the act of killing oneself, or the method of suicide that was undertaken.[6] The contents of a suicide note could be intended to make the addressee suffer or feel guilt. Genuine suicide letters are short, typically less than 300 words in length.[2] Extraneous or irrelevant material is often excluded from the text.[6]

Death row statements

Death row statements either admit the crime, leaving the witness with an impression of honesty and forthrightness; or deny the crime, leaving the witness with an impression of innocence. They may also denounce witnesses as dishonest, critique law enforcement as corrupt in an attempt to portray innocence or seek an element of revenge in their last moments (Olsson 2004). Death row statements are within the heavily institutionalized setting of death row prisons. The Forensic Linguistics Institute holds a corpus of these documents and is conducting research on them.

Social media

Social media statements are often context specific, and their interpretation can be highly subjective. Forensic application of a selection of stylistic and stylometric techniques in a simulated authorship attribution case involving texts has been done in relation to Facebook.[7] Analysis of social media postings can reveal whether they are illegal (e.g. sexist) or ethical (e.g. intended to harm) or whether they are not (e.g. simply provocative or free speech).[8]

Use of linguistic evidence in legal proceedings

These areas of application have varying degrees of acceptability or reliability within the field. Linguists have provided evidence in:

Specialist databases of samples of spoken and written natural language (called corpora) are now frequently used by forensic linguists. These include corpora of suicide notes, mobile phone texts, police statements, police interview records and witness statements. They are used to analyse language, understand how it is used, and to reduce the effort needed to identify words that tend to occur near each other (collocations or collocates).

Author identification

The identification of whether a given individual said or wrote something relies on analysis of their idiolect,[10] or particular patterns of language use (vocabulary, collocations, pronunciation, spelling, grammar, etc). The idiolect is a theoretical construct based on the idea that there is linguistic variation at the group level and hence there may also be linguistic variation at the individual level. William Labov has stated that nobody has found a "homogenous data" in idiolects,[11] and there are many reasons why it is difficult to provide such evidence.

Firstly, language is not an inherited property, but one which is socially acquired.[12] Because acquisition is continuous and life-long, an individual's use of language is always susceptible to variation from a variety of sources, including other speakers, the media and macro-social changes. Education can have a profoundly homogenizing effect on language use.[2] Research into authorship identification is ongoing. The term authorship attribution is now felt to be too deterministic.[13]

The paucity of documents (ransom notes, threatening letters, etc) in most criminal cases in a forensic setting means there is often too little text upon which to base a reliable identification. However, the information provided may be adequate to eliminate a suspect as an author or narrow down an author from a small group of suspects.

Authorship measures that analysts use include word length average, average number of syllables per word, article frequency, type-token ratio, punctuation (both in terms of overall density and syntactic boundaries) and the measurements of hapax legomena (unique words in a text). Statistical approaches include factor analysis, Bayesian statistics, Poisson distribution, multivariate analysis, and discriminant function analysis of function words.

The Cusum (Cumulative Sum) method for text analysis has also been developed.[14] Cusum analysis works even on short texts and relies on the assumption that each speaker has a unique set of habits, thus rendering no significant difference between their speech and writing. Speakers tend to utilize two to three letter words in a sentence and their utterances tend to include vowel-initial words.

In order to carry out the Cusum test on habits of utilizing two to three letter words and vowel-initial words in a sentential clause, the occurrences of each type of word in the text must be identified and the distribution plotted in each sentence. The Cusum distribution for these two habits will be compared with the average sentence length of the text. The two sets of values should track each other. Any altered section of the text would show a distinct discrepancy between the values of the two reference points. The tampered section will exhibit a different pattern from the rest of the text.

Forensic stylistics

This discipline subjects written or spoken materials (or both), to scientific analysis for determination and measurement of content, meaning, speaker identification, or determination of authorship, in identifying plagiarism.[15]

One of the earliest cases where forensic stylistics was used to detect plagiarism was the case of Helen Keller's short story "The Frost King". The blind American author was accused of plagiarism in 1892 with regard to the short story. Upon investigation, The Frost King was found to have been plagiarised from Margaret Canby's book Frost Fairies which had been read to her some time ago. Keller was discovered to have made only minute changes to common words and phrases and used less common words to put the same point across, suggesting mere alterations to original ideas.

Keller used 'vast wealth' instead of 'treasure' (approximately 230 times less common in the language) 'bethought' instead of 'concluded' (approximately 450 times less common), 'bade them' instead of 'told them' (approximately 30 times less common). Keller used the phrase 'ever since that time' whilst Canby chose 'from that time' (the latter 50 times more common than the former). Keller also used ' I cannot imagine' whereas Canby used ' I do not know'. 'Know' is approximately ten times more common than 'imagine'.

Keller relied on a lexis that is less common when compared to Canby's. The Flesch and Flesch-Kincaid readability test showed that Canby's text showing more originality compared to Keller's. Canby's text obtained a higher grade on the reading ease scale compared to Keller's. The distinctions between Keller and Canby's text are at the lexical and phrasal level.

Other examples of plagiarism include the cases between Richard Condon, author of The Manchurian Candidate and English novelist Robert Graves; and between Martin Luther King Jr and Archibald Carey.

Judging by the text in The Manchurian Candidate, Condon's work is seen to be rich in clichés such as "in his superstitious heart of hearts." While Helen Keller took pride in using rare phrases and avoids common source words, Condon was fond of expanding existing words into phrases and existing phrases into more extensive ones. Condon was also found to have borrowed from a wide range of Graves' work.[2]

In the plagiarism case of Martin Luther King Jr, almost half of his doctoral dissertation was discovered to have been copied from another theology student. King simply changed the names of the mountains and used much more alliteration and assonance.[16]

Carey's and Graves' texts (source texts) were noticeably shorter, pithier and simpler in structure while Condon's and King's texts relied on 'purple' devices, extending the existing text and flourish their language significantly.

Discourse analysis

Discourse analysis deals with analyzing written, oral, or sign language use, or any significant semiotic event. According to the method, the close analysis of a covert recording can produce useful deductions. The use of 'I' instead of 'We' in a recording highlights non-complicity in a conspiracy. The utterance of 'yeah' and 'uh-huh' as responses indicate that the suspect understands the suggestion, while feedback markers such as 'yeah' and 'uh-huh' do not denote the suspect's agreement to the suggestion. Discourse analysts are not always allowed to testify but during preparation for a case they are often useful to lawyers.

Linguistic dialectology

This refers to the study of dialects in a methodological manner based on anthropological information. It is becoming more important to conduct systematic studies of dialects, especially within the English language, because they are no longer as distinct as they once were due to the onslaught of mass media and population mobility. Political and social issues have also caused languages to straddle geographical borders resulting in certain language varieties spoken in multiple countries, leading to complications when determining an individual's origin by means of his/her language or dialect.

Dialectology was used during the investigations into the Yorkshire Ripper tape hoax.[17]

Forensic phonetics

The forensic phonetician is concerned with the production of accurate transcriptions of what was being said. Transcriptions can reveal information about a speaker's social and regional background. Forensic phonetics can determine similarities between the speakers of two or more separate recordings. Voice recording as a supplement to the transcription can be useful as it allows victims and witnesses to indicate whether the voice of a suspect is that of the accused, i.e., alleged criminal.

A man accused of manufacturing the drug Ecstasy was mis-heard by the police transcriber as 'hallucinogenic' [18] The police transcriber heard "but if it's as you say it's hallucinogenic, it's in the Sigma catalogue." However, the actual utterance was "but if it's as you say it's German, it's in the Sigma catalogue."

Another disputed utterance was between a police officer and a suspect. One of the topics of conversation was a third man known as 'Ernie'. The poor signal of the recording made 'Ernie' sound like 'Ronnie'. The surveillance tape presented acoustic problems- an intrusive electronic-sounding cackle, the sound of the car engine, the playing of the car radio, the movement of the target vehicle, and the intrusive noise coincided with the first syllable of the disputed name.[2]

Forensic speechreading is the complement of forensic voice identification. Transcripts of surveilled video records can sometimes allow expert speechreaders to identify speech content or style where the identity of the talker is apparent from the video record.


Evidence from forensic linguistics has more power to eliminate someone as a suspect than to prove him or her guilty. Linguistic expertise has been employed in criminal cases to defend an individual suspected of a crime, and during government investigations. Forensic linguists have given expert evidence in a wide variety of cases, including abuse of process, where police statements were found to be too similar to have been independently produced by police officers; the authorship of hate mail; the authorship of letters to an Internet child pornography service; the contemporaneity of an arsonist's diary; the comparison between a set of mobile phone texts and a suspect's police interview, and the reconstruction of a mobile phone text conversation. Some well-known examples include an appeal against the conviction of Derek Bentley and the identification of Theodore Kaczynski as the so-called "Unabomber".

The criminal laboratories Bundeskriminalamt (in Germany) and the Nederlands Forensisch Instituut (in the Netherlands) both employ forensic linguists.[9]

Forensic linguistics contributed to the overturning of Derek Bentley's conviction for murder in 1998 although there were other non-linguistic issues. Nineteen-year-old Bentley, who was functionally illiterate, had been hanged in 1953 for his part in the murder of PC Sidney Miles; he had been convicted partly on the basis of his statement to police, allegedly transcribed verbatim from a spoken monologue. When the case was reopened, a forensic linguist found that the frequency and usage of the word "then" in police transcripts suggested the transcripts were not verbatim statements but had been partially authored by police interviewers; this and other evidence led to Bentley's posthumous pardon.[19]

In the case of Theodore Kaczynski, who was eventually convicted of being the "Unabomber", family members recognized his writing style from the published 35,000-word Industrial Society and Its Future (commonly called the "Unabomber Manifesto"), and notified the authorities. FBI agents searching Kaczynski's hut found hundreds of documents written by Kaczynski but not published anywhere. An analysis produced by FBI Supervisory Special Agent James R. Fitzgerald identified numerous lexical items and phrases common to the two documents.[20] Some were more distinctive than others, but the prosecution argued that even the more common words and phrases being used by Kaczynski became distinctive when used in combination with each other.[18]

Forensic linguistic evidence also played a role in the investigation of the 2005 disappearance of Julie Turner, a 40-year-old woman living in Yorkshire. After she was reported missing, her partner received several text messages from Julie's mobile phone, such as "Stopping at jills, back later need to sort my head out", and "Tell kids not to worry. sorting my life out. (sic) be in touch to get some things".[21] Investigators found that letters written by Turner's friend Howard Simmerson shared several unusual orthographic and punctuation features with the text messages, suggesting that Simmerson had been aware of the contents of the messages.[22] Simmerson was eventually found guilty of Turner's murder.[23]

Forensic linguist John Olsson gave evidence in a murder trial on the meaning of 'jooking' in connection with a stabbing.[24]

During the appeal against the conviction of the Bridgewater Four, the forensic linguist examined the written confession of Patrick Molloy, one of the defendants  a confession which he had retracted immediately  and a written record of an interview which the police claimed took place immediately before the confession was dictated. Molloy denied that the interview had ever taken place, and the analysis indicated that the answers in the interview were not consistent with the questions being asked. The linguist came to the conclusion that the interview had been fabricated by police. The conviction against the Bridgewater Four was quashed before the linguist in the case, Malcolm Coulthard, could produce his evidence.

In an Australian case reported by Eagleson, a "farewell letter" had apparently been written by a woman prior to her disappearance. The letter was compared with a sample of her previous writing and that of her husband. Eagleson came to the conclusion that the letter had been written by the husband of the missing woman, who subsequently confessed to having written it and to having killed his wife. The features analysed included sentence breaks, marked themes, and deletion of prepositions.[25]

Additional forensic linguistics concepts

Linguistic fingerprinting

A linguistic fingerprint is a concept put forward by some scholars that each human being uses language differently, and that this difference between people involves a collection of markers which stamps a speaker/writer as unique; similar to a fingerprint. Under this view, it is assumed that every individual uses languages differently and this difference can be observed as a fingerprint.[2] It is formed as a result of merged language style. A person's linguistic fingerprint can be reconstructed from the individual's daily interactions and relate to a variety of self-reported personality characteristics, situational variables and physiological markers (e.g. blood pressure, cortisol, testosterone).[26] In the process of an investigation, the emphasis should be on the relative rather than absolute difference between the authors and how investigators can classify their texts. John Olsson, however, argues that although the concept of linguistic fingerprinting is attractive to law enforcement agencies, there is so far little hard evidence to support the notion.[2]


Intra-author variations are the ways in which one author's texts differ from each other. Inter-author variations are the ways in which different authors' writing varies. Two texts by one author do not necessarily vary less than texts by two different authors.

Forensic transcription

The two main types of transcriptions are written documents and video and audio records. Accurate, reliable text transcription is important because the text is the data which becomes the available evidence. If a transcription is wrong, the evidence is altered. If there is failure to transcribe the full text, evidence is once again altered unwittingly. There must be emphasis on the text being the evidence. A transcription of an audio file should never be assumed to be completely accurate. Each type of transcription contains its own problems. A handwritten document might contain unusual spellings which may result in ambiguous meanings, illegible handwriting and illustrations that are difficult to comprehend. A scanned document is tricky, as it may alter the original document. Audio and video documents can include repetitions, hesitation, nonsensical talk, jargon which can be hard to understand and speakers mumbling incoherently and inaudibly. Non-linguistic sounds such as crying and laughing may also be included in the audio and video text which cannot be transcribed easily. Because of this, civil libertarians argued that interrogations in major criminal cases should be recorded and the recordings kept, as well as transcribed.[27]

See also


  1. "Centre for Forensic Linguistics". Aston University.
  2. 1 2 3 4 5 6 7 8 9 10 John Olsson (2008).. Forensic Linguistics, Second Edition. London: Continuum ISBN 978-0-8264-6109-4
  3. Ayres, Jr, B. Drummond (22 July 1988). "McDonald's, to Court: 'Mc' Is Ours". New York: The New York Times. Retrieved 19 March 2012.
  4. "The Kidnapping". PBS Online.
  5. Falzini, Mark W. (9 September 2008). "The Ransom Notes: An Analysis of Their Content & "Signature"". Archival Ramblings.
  6. 1 2 John Olsson (2004). An Introduction to Language Crime and the Law. London: Continuum International Publishing Group
  7. C.S. Michell (2013). Investigating the use of forensic stylistic and stylometric techniques in the analysis of authorship on a publicly accessible social networking site (Facebook) (PDF) (MA in Linguistics thesis). University of South Africa.
  8. C. Hardaker (2015). The ethics of online aggression: Where does “virtual” end, and “reality” begin? BAAL Conference on The Ethics of Online Research Methods. Cardiff. Available online.
  9. 1 2 Peter Tiersma, What is Forensic Linguistics?
  10. Coulthard, M. (2004). Author identification, idiolect and linguistic uniqueness. Applied Linguistics, 25(4), 431-447.
  11. Labov, William (1972) Sociolinguistic patterns. Philadelphia, PA: University of Pennsylvania Press, p192.
  12. Miller, C. (1984). "Genre as social action." Quarterly Journal of Speech, pp 151-167
  13. Grant, T. D. (2008). Approaching questions in forensic authorship analysis. In J. Gibbons & M. T. Turell (Eds.), Dimensions of Forensic Linguistics. Amsterdam: John Benjamins.
  14. Morton, A.Q., and S. Michaelson (1990) The Qsum Plot. Internal Report CSR-3-90, Department of Computer Science, University of Edinburgh.
  15. "How does forensic linguistics/stylistics work in criminal issues? Answers". March 5, 2014.
  16. "Boston U. Panel Finds Plagiarism by Dr. King". The New York Times. 11 October 1991. Retrieved 2008-06-14.
  17. Martin Fido (1994), The Chronicle of Crime: The infamous felons of modern history and their hideous crimes
  18. 1 2 Coulthard, M., & Johnson, A. (2007). An introduction to forensic linguistics: Language in evidence. Oxford: Routledge:162-3.
  19. Coulthard, R.M. (2000). " Whose text is it? On the linguistic investigation of authorship ", in S. Sarangi and R.M. Coulthard: Discourse and Social Life. London, Longman.
  20. Fitzgerald, J. R. (2004). "Using a forensic linguistic approach to tracking the Unabomber." In J. Campbell, & D. DeNevi (Eds.)Profilers: Leading investigators take you inside the criminal mind (pp. 193-222). New York: Prometheus Books.
  21. Speech Patterns in Messages Betray a Killer, Elizabeth Svoboda, New York Times May 11, 2009
  22. Dear Garry. I've decided to end it all: The full stop that trapped a killer, Daily Mail, 3 July 2009
  23. "Life term for man who shot lover". BBC News. 8 November 2005. Retrieved 16 November 2011.
  24. Trial of Rehan Asghar, Central Criminal Court, London, January 2008.
  25. Eagleson, Robert. (1994). 'Forensic analysis of personal written texts: a case study', John Gibbons (ed.), Language and the Law, London: Longman, 362373.
  26. Pennebaker, J. W. (1990). 'Physiological factors influencing the reporting of physical symptoms'. The Science of Self-report: Implications for Research and Practice. Mahwah, NJ: Erlbaum Publishers, pp. 299-316
  27. "Recording Police Questioning". The New York Times. 15 June 2004.

1 - Coulthard, M. and Johnson, A. (2007)

25 - Forensic linguistics; An Introduction to Language, Crime and Law (with original cases in Bureau of Police Investigation and Courts) by Azizi, Syrous & Momeni, Negar, Tehran: JahadDaneshgahi Publication, 2012.

Further reading

External links

This article is issued from Wikipedia - version of the 9/5/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.