Forensic Linguistics and Its Role in Criminal Investigations

Introduction

“In Richard Price's novel "Lush Life," a detective explains how he determines whether someone is lying about his level of participation in a crime: "When we're interviewing somebody who claims to be a witness but we think he was maybe a little more…involved than that? It's called an I-test. You sit them down and take their statement, written, dictated, whatever, and when you're finished, you count up and divide the pronouns. If a girl gets shot and the boyfriend's story consists of sixteen Is and mys, but only three hers and shes?--he just flunked”. The technique he describes in this passage is a crude form of the discipline known as forensic linguistics.”

Linguistics is the scientific study of all aspects of human language. Linguistics consists of various sub-fields such as:

1. Phonetics is the study of sounds and analyses how our brain is able to tell these sounds apart.
2. Phonology studies how sounds or signs are arranged in each language, and how changing the order changes the meaning of the sentence.
3. Morphology studies how individual words are formed from smaller meaningful units called morphemes. “For example, the English word 'untied' is made up of three parts, one refering to the process of reversing an action (un-), one indicating the action of twisting string like things together so they stay (tie), and the last indicating that the action happened in the past (-d).” 2: 'What Is Linguistics?'
4. “Syntax is the study of how phrases, clauses and sentences are combined in particular languages.”
5. Semantics is study of the meaning of words or phrases.
6. Pragmatics involves the study of how speakers of a language communicate with one another. It analyses the context of the spoken content and how the spoken content derives meaning from its context..
7. “Historical Linguistics is the study of how languages have changed over time.”
8. Sociolinguistics is the study of how social factors such as location, age group, ethnicity contribute to the variations is language (e.g. dialects)

Forensic linguistics is the branch of linguistics that applies rigorous, scientifically accepted principles of linguistics to issues of law and legal evidence. It has two sub fields

1. written, which includes analysis if textual matter and
2. spoken, analysis of speech and paraverbal cues.

Some of the most frequently used applications include the following:

• Voice identification.
• Dialectology: to identify an individual by analyzing his dialect and manner of speaking.
• Language analysis: Identification of a speaker’s dialect and native language.
• Discourse analysis: analyses conversations to figure out who was the first person to introduce an idea. It is mainly used in criminal cases.
• “Linguistic proficiency, to help figure out whether a person understood his or her rights.”

Forensic Linguistics can be applied to a wide range of cases and situations in which language could be considered evidence. Yet, regardless of its extensive uses, forensic linguistics is still an underutilized tool.

Body

The History And Use Of Forensic Linguistics

History of Forensic Linguistics

Professor Jan Svartvik, famously known as the father of forensic linguistics, coined the term ‘forensic linguistics’ and used it for the first time in his most famous work “The Evans Statements: A Case For Forensic Linguistics” in which he spoke about his work in the Timothy John Evans Case ( refer to case 1 in appendix-1). This was the beginning of the use of forensic linguistics as evidence in the field of law.

Uses Of Forensic Linguistics In Criminal Investigation

In reference to case 2 in the Appendix-1, we see the role that language plays in criminal investigation and how forensic linguistics can be used to clear such barriers and solve issues that may crop up during criminal investigation. Though there are many uses of forensic linguistics this paper shall exclusively focus on handwriting analysis and authorship attribution.

Handwriting analysis:

Everyone has a different fingerprint; in the same manner every individual’s handwriting is unique to that individual. A thorough analysis of a person’s handwriting can reveal their identity and also their state of mind while writing the said text. What makes a person’s handwriting unique is that there will always be variations in “Angularity of letters, slope, speed of writing, pressure exerted, letter and word spacing, relative dimensions of letters, connections, pen movement, writing skill, and finger dexterity” in the writings of two individuals. [7: 'How Forensic Linguistics Can Aid Investigations' ] Handwriting analysis aims to verify the authenticity of a document whose validity is the subject of investigation. Most cases that involve handwriting and document examination are those relating to fraud. A document examiner focuses on answering 3 questions while analyzing a document: “

1. Is the document genuine?
2. Has the document been changed in any way and how was it changed?
3. Which person or machine wrote and produced the document?”

Handwriting analysis is usually done through comparisons with examples (handwriting samples). A person’s writing style can change depending on the type of paper used and the instrument of writing used; hence, it is necessary that one must collect a large number of examples to show the examiner the natural variations in an individual's handwriting. One more important point to be kept in mind while conducting a handwriting analysis is that comparisons of a document must be done with similar samples. For example, if the authenticity of a signature is in question then that signature must be compared to samples of the same signature. To identify the authenticity of a signature one must focus on the quality of the lines and the design of the letters. The above picture shows the natural variations in one's signature. Though all 4 look different, by looking closely at the shape of the letter ‘y’, ‘r’ ,‘h’ and ‘t’; along with analyzing the spacing between the words, which are similar in all the 4 samples, we can conclude that the signature is by the same person. The below five points can be conclusively established, after an analysis:

• Positive Identification – when the suspect’s sample matches that of the document in question to rule out all possibilities of other possible writers.
• Probable Identification - there are a combination of similarities pointing to one writer, however, this alone cannot establish validity of the evidence, and it leaves only theoretical possibility of another writer.
• Unable to Determine - there are not enough examples to reach a conclusion.
• Probable Elimination - the exemplars and the suspects’ samples do not match; the suspect cannot be excluded from investigation.
• Positive Elimination - the suspect's sample and the exemplars do not match at all, eliminates the suspect as the author.

A suspect will try their best to alter and modify their style of writing when asked for a sample of writing, it is therefore safer for one to obtain handwriting samples of the suspect from their home or their personal writing which was not done under duress. There are certain methods that are employed by the police and other handwriting examiners to get the best results from their suspects, these include:

1. Making sure that the suspect is sitting comfortably at a desk
2. Giving the suspect a pen and paper which is similar to the document in question
3. Dictating to the suspect a text that contains certain words or phrases similar to the document in question
4. The text must be dictated at-least thrice, as noticeable discrepancies will be seen if one is intentionally trying to modify their handwriting.
5. Signatures of the suspect must be obtained with a combination of other writings, as only asking for their signatures gives them ample room to think and modify it.

Authorship attribution:

Handwriting analysis includes Author attribution. “Authorship attribution is concerned with identifying authors of disputed or anonymous documents, which are potentially evidential in legal cases, through the analysis of linguistic clues left behind by writers.” This can be seen in reference to case 2 in appendix 1 in which Dr. Shuy was able to come up with a positive description of the suspect based on his idiolect. Idiolect refers to the way a person speaks and writes a particular language. An individual’s idiolect is unique just like their fingerprint. It is influenced by various factors such as practice, exposure to the language, the person’s profession and his geographic location. In case 1 of appendix-1, Jan Svartvik was able to identify the ‘police speak’ (the language, style of writing and speaking that is a common characteristic of police officers) that was used in the recorded statements. Instead of writing the statements verbatim they wrote down not only their perception of what the suspect said, but also their own opinions about the statement, which in turn corrupted the integrity of the recorded statements and inevitably led to the conviction of Evans, an innocent man. In case 2 of appendix-1, Dr. Shuy mentions how the use of the word ‘devil strip’ gave away the criminal’s identity. ‘Devil strip’ is an example of the idiolect of the suspect which was influenced by the geographic location of his birthplace i.e. Akron, Ohio. The idiolect of an individual not only includes their vocabulary and the way they pronounce words but also the way they use punctuations, the spacing between words when they write and certain phrases which they commonly use.

Conclusion

Forensic linguistics, though a very comprehensive field of study, is an underutilized one. There are many uses of forensic linguistics in criminal investigation, ranging from analysis of written and textual documents to speech and phonetic analysis. Forensic linguistics in criminal investigation relies on the analysis of language and style of writing used in-order to dispense justice. This can be witnessed in reference to the Evans case’ (in which professor Svartvik was able to detect the tampering of the suspects statement by the police) and the case handled by Dr. Shuy (where by analyzing the use of the word ‘devil strip’ he was able to positively identify the culprit). It must be remembered that forensic linguistics does not deal with whether a suspect is guilty of crime or not, it only focuses on identifying the author of a given text.

Appendix

In the Timothy John Evans Case (1950), Timothy John Evans went to the police station in South Wales and said that he had “disposed of'' his wife. The police initiated an investigation based on his statement and found her body, together with that of their daughter, at his home in London. Evans was taken into custody. He made four statements to the police, all of which, though detailed, contradicted each other. In the absence of other suspects at the time, Evans was convicted of the murder of his wife and daughter and was hence, hanged.In one of his four statements Evans had mentioned a man named John Christie, one of the other tenants in the building in which the Evans lived. Timothy Evans claimed that John Christie was the murderer of his wife and daughter. This statement did not convince the jury during the trial hence, did not take it into consideration. 3 years after Evans death it was revealed that John Christie was a serial killer, which brought up his case before the Court again. A committee was formed to campaign on Evans’s behalf. A member of the committee invited Jan Svartvik to apply his expertise of textual analysis to the Evans statements.Svartvik, by analyzing the grammar used in the recorded statements, found out that the statements recorded by the police, though claimed to be transcribed word to word, had actually been produced by more than one policeman.

The police had transcribed Evans’s oral statements based on what they understood instead of writing them verbatim and the section of the text that had incriminated Evans too was transcribed based on the police’s understanding and opinion of what Evans had said. After this revelation the court pardon Evans, this revelation also brought about the abolition of capital punishment in Great Britain in 1965.This was the beginning of the use of forensic linguistics as evidence in the field of law.

Case 2

Roger Shuy, a famous linguist, was given a “pencil-scrawled ransom note, left at the doorstep of the parents of an abducted juvenile” by the police to analyse. [11: international journal of humanities ] “The note read:Do you ever want to see your precious little girl again? Put $10,000 cash in a diaper bag. Put it in the green trash can on the devil strip at corner 18th and Carlson.Don’t bring anybody along. No kops!! Come alone! I’ll be watching you all the time. Anyone with you, deal is off and the daughter is dead!!!” On examination, Dr. Shuy noticed that the ransom note had a lot of spelling mistakes e.g. kops, daughter and kan. Dr. Shuy found it weird that a person who couldn’t spell ‘cops’ was able to spell ‘precious’ and ‘diaper’. He also noticed that the punctuation used and the sentence structure indicated that the writer of the ransom note was well versed and fluent in English. He therefore deduced that the person who wrote the ransom note was in fact an educated person who was intentionally mis-spelling words in an attempt to hide their identity.

What stood out the most for Dr. Shuy was the use of the word ‘devil strip’. ‘Devil strip’ refers to a strip of grass that is found between the sidewalk and the road, and interestingly residents of Akron, Ohio were the only ones to use this word. Hence, Dr. Shuy was able to come to the conclusion that the writer was a well-educated person from Akron, Ohio. This example brings up two important points. First, linguistics helps build a profile, not identify an individual. Second, even when someone attempts to disguise his language, there is simply too much that is not under his conscious control. We have evidence, like his spelling, that this writer intended to disguise his language—but he did not disguise (oravoid) the telltale phrase devil strip. People are generally not aware that their speech differs from everyone else’s, unless something occurs to highlight that fact. In the above case it was the use of the phrase ‘devil strip’. The writer unconsciously believed that since the use of ‘devil strip’ was common in his hometown that it would be commonly in use everywhere else too. It was this mistake that gave him away, without the use of ‘devil strip’ it would have been impossible to determine the identity of the accused.