What is Linguistic Evidence?

A text with some value in legal proceedings comes in many different forms to police officers, detectives, private investigators, security specialists, intelligence analysts, attorneys and private individuals. Some civil disputes are obviously associated with certain types of linguistic evidence, such as trademarks, service marks, and patent applications. In certain criminal scenarios, some forms of linguistic evidence are likewise obvious: a bank robbery note, a threat letter, a suicide note, a ransom note.

SOMETIMES THE LINGUISTIC EVIDENCE IN A CASE IS OBVIOUS, SOMETIMES INVESTIGATORS MUST SEARCH FOR IT

It is clear, from these kinds of documents, that linguistic evidence can play a crucial role in investigating a crime, and the crime with which such a document is associated is also obvious, (although sometimes this kind of document is a red herring to cover up a different kind of crime). For instance, in actual cases, a suicide note has been written to disturb or cover up a murder; a threat letter has been sent in order to mislead investigators away from conspirators.  Whether in civil or criminal scenarios, the words themselves are critical pieces of evidence in proving some aspect of the crime or civil trespass.

Other kinds of linguistic evidence are not so well-known, and the crimes or civil actions to which they attach are likewise not so obvious. Blog posts, dating website profiles, handwritten codicils and wills, business emails and memoranda, personal emails within a family or corporation, graffiti sprayed on a shop’s wall -these kinds of linguistic evidence can occur in many different crimes or civil and security investigations.

FUNDAMENTAL QUESTIONS ASKED ABOUT LANGUAGE-BASED EVIDENCE

At ILE our research agenda is set for the “four corners of forensic linguistics,” (Chaski 2013), to reflect the fundamental questions we have been asked, repeatedly, about some document relevant to a case. Often the crucial investigative issues are:

  1. author/speaker identification: Who authored this document? Who spoke this voicemail message?
  2. text similarity: Are these texts or screen names related to each other? Are these trademarks too similar? Are these manuals too close for comfort?
  3. text typing: Is this document really what it purports to be — is it a real suicide note, a real threat letter, a real confession, a real predatory chat, etc?
  4. linguistic profiling: What can be determined about the author’s background from this text?

STAKEHOLDERS FOR LINGUISTIC EVIDENCE

The stakeholders for linguistic evidence are

  • law enforcement,
  • private and civil investigators,
  • the national, business and executive security communities,
  • the academic and research community,
  • the legal community, and
  • any citizen whose life, liberty and finances are being affected by the proper or improper use of linguistic evidence in criminal or civil litigation.
    From its inception, ILE has recognized our stakeholders’ need for reliable methods of answering the fundamental questions. ILE has a history of testing methods to find out how well they work.