Forensic linguists can make or break a court case. So who are they and what do they do?

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If you’re an avid viewer of crime shows, you’ve probably come across cases in which an expert, often a psychologist, is called in to help solve a crime using their language analysis skills.

However, in real life it’s the job of forensic linguists like myself to provide such evidence in courts, here in Australia and around the world.

Forensic linguists can provide expert opinion on a variety of language-related dilemmas, including unattributed voice recordings, false confessions, trademark disputes and, of course, a fair share of threatening letters.

But what do we look for when doing this?

Reading between the lines (and everything else)

Linguistics is the scientific study of language. Thus, linguists are uniquely placed to provide expert opinions on how language is used. Linguists study:

  • grammatical structures, wherein changes in punctuation patterns between texts can signal different authors
  • semantics, which explores how speakers and listeners form meaning, such as when making sense of a written text
  • phonetics and phonology, which refer to the sounds of language. We can recognise subtle differences in the sound of a vowel when produced by different speakers, or by speakers of different dialects and languages.
  • sociolinguistics, which looks at how language use varies across different social groups. For example, we can identify when someone from a non-English language background might misunderstand a question. This is because the variety of English they’re familiar with would differ, in small but notable ways, from native English speakers.

Since the first known forensic linguistic case in 1953, all of the above abilities have proven invaluable in courts time and time again. Yet the work done by forensic linguists seems to largely elude members of the public.

A widely misunderstood field

Ironically, a big problem for forensic linguists (and linguistics in general) relates to language. It comes down to how we use the word “linguist”.

Some people think this refers to a person who speaks many different languages, or is particularly fluent in their speech or writing. These non-technical interpretations are easy to conflate with the academic discipline of linguistics.

But apart from causing linguists a headache at dinner parties, does it really matter if people misunderstand what linguists do?

It seems so. Widespread ignorance on the vitality of forensic linguistics has led to some of the most egregious miscarriages of justice in Australian history.

In 2018, the Western Australia Court of Appeal overturned the conviction of manslaughter for Gene Gibson, an Aboriginal man with a cognitive impairment for whom English was a third language.

Police interviewed Gibson without an interpreter, assuming one wasn’t needed to assess his English fluency. This neglect resulted in Gibson spending nearly five years in prison for a crime he didn’t commit.

People who speak English as an additional language sometimes don’t know their legal rights in situations such as police interviews.

In the past, these defendants or witnesses have been treated as though they understood complex legal English simply because they could chat about the weather, or their family.

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