Forensic linguistics is a sub-field of applied linguistics that uses the study of language to solve crimes. Forensic linguists use their knowledge of grammar, syntax, semantics, phonetics, and sociolinguistics to analyze written and spoken language in order to identify the author of a text, determine the authenticity of a document, or interpret the meaning of a statement.

Forensic linguists may be called upon to investigate a wide variety of crimes, including:

• Authorship analysis: Forensic linguists can use their knowledge of language to identify the author of a text, even if the author has tried to conceal their identity. This is often done by comparing the linguistic features of the text to the known linguistic features of the author.
• Authenticity analysis: Forensic linguists can also be used to determine the authenticity of a document. This is often done by looking for inconsistencies in the document's language, such as changes in grammar or vocabulary that suggest that the document was written by more than one person.
• Meaning analysis: Forensic linguists can also be used to interpret the meaning of a statement. This is often done by considering the context in which the statement was made, as well as the linguistic features of the statement itself.

Forensic linguists play an important role in the criminal justice system. They can help to solve crimes, exonerate the innocent, and ensure that justice is served.

Here are some examples of how forensic linguists have been used in criminal investigations:

• In the 1990s, a forensic linguist was used to help identify the author of the Unabomber manifesto. The linguist was able to identify linguistic features in the manifesto that were consistent with the known linguistic features of Ted Kaczynski, who was eventually convicted of the crimes.
• In 2002, a forensic linguist was used to help determine the authenticity of a letter that was purportedly written by Adolf Hitler. The linguist was able to identify linguistic features in the letter that were inconsistent with Hitler's known linguistic style, leading to the conclusion that the letter was a forgery.
• In 2016, a forensic linguist was used to help interpret the meaning of a statement made by a witness in a criminal trial. The linguist was able to show that the witness's statement was ambiguous, and that it could be interpreted in two different ways. This evidence helped to exonerate the defendant, who was ultimately found not guilty.

Forensic linguistics is a growing field, and forensic linguists are increasingly being called upon to help solve crimes. As the field continues to develop, forensic linguists will play an even more important role in the criminal justice system.