Can you use language to solve a crime?
22 September 2005
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People who work with languages do a lot of things you probably never thought of. Think about this scenario:
It's a dark and stormy night. You're leaving a party, and when you get in your car, your car says, "Count to five." It won't start unless you do, so you count: one, two, three, four, five. "Sorry, says your car, you've had too much to drink," and shuts off.
By analyzing your voice, the car's computer knows you're intoxicated. Your voice can tell a lot about you: where you grew up, your emotional state, whether you're lying -- even who you are. And voice analysis is one of the things that linguists do; it's part of a field known as Forensic Linguistics. It's the application of linguistic science to matters concerning the law, crime, and the courts.
In voice analysis, speech is broken down electronically, using a computer, and then examined for clues about the speaker. You've probably heard it called a 'voiceprint.' Because your voice may change over time, or with illness, voiceprints aren't as accurate as
fingerprints -- which are unchanging from birth to death -- but they're a very useful tool in solving crimes.
And then there's analysis of writing. Consider The Case of the Dog Club Letters. No, this isn't a Sherlock Holmes story. It's an actual case where the committee members of a dog club received threatening, anonymous letters. Personal details in each letter hinted that the writer was actually a committee member, but which one?
A forensic linguist compared the letters with the writings of each member. Analysis of their writing styles, including punctuation, capitalization, and spelling, revealed that the letter writer was... the dog club's treasurer. He was drummed out of the club.
Ranging from doggy letters to the text of stage plays that may or may not have been written by Shakespeare, authorship can be determined by comparing patterns such as word groupings, sentence length, grammatical usages, and much more. This, by the way, is how forensic linguists used computer programs to identify the author of some of the Federalist Papers, which had been in dispute for two hundred years.
And remember those anthrax letters that followed the nine-eleven attack? The question came up: were the letters written by foreigners, suggesting a connection to nine-eleven? Analysis of the letter sent to Senator Tom Daschle showed the writer had great familiarity with the Roman alphabet, far more than most Arabic writers might have. Forensic linguistics revealed that the broken English and misspelled words were faked, and that the letters were written by a native English speaker.
A bane of education is plagiarism -- often by students who take other people's writings from the Internet. Forensic Linguistics to the rescue! The same techniques used on the Federalist Papers can be used to detect whether material is plagiarized. Computer software reads a student paper, then scans millions of written works for duplication of specific words, phrases, sentences -- even ideas.
Finally, a major concern of Forensic Linguistics is to clarify legal talk, so that people can understand the meaning of a law that may be couched in gobbledygook. For example, on the subject of expert witnesses the law reads: "Expert evidence presented to the court should be, and should be seen to be, the independent product of the expert uninfluenced as to form or content by the exigencies of litigation." The forensic linguist simplifies this to say, "Expert witnesses should be free from prejudice." Today, linguists are designing computer programs that automatically translate legalese into ordinary English.
So, there's a lot going on in this field. If you want to learn more, just Google the words 'Forensic' and 'Linguistics'. And the next time you think of crime fighting super heroes, forget the cape and bulging muscles -- and picture a laptop-toting linguist.
That's the linguistic thought for today, which comes from Dr. Robert D. Rodman, Professor in the Department of Computer Science at North Carolina State University. And this is the Five-Minute Linguist at the College of Charleston, in cooperation with the National Museum of Language. Visit us at www.cofc.edu/linguist. And keep in mind that wherever you are, and whatever you do... language makes a difference.