Evidence of individual identity almost as incriminating as a fingerprint can be gleaned from how we use language.
“A lot of us litter our writings, our texts, our e-mails, and our letters with a little bit of ourselves,” said author and storyteller Jack Hitt. As forensic linguistics has become more accepted in American courtrooms, he said, testimony from linguists has sealed both convictions and acquittals. Hitt, who gave the James Kenney Lecture in September for the Program for Humanities in Medicine, wrote an article about the topic for The New Yorker in July.
In one case, although the physical evidence was not overwhelming, a jury found a man guilty of killing his family based largely on the linguistic constructions in anonymous threatening e-mails sent before the murders. Consistently misplaced apostrophes and fused spellings (“goodtime”) were identical to material that the suspect was known to have written.
Forensic linguists look “for any kind of unconscious pattern,” Hitt said. They also listen to voice recordings for “the beats in that sentence and the pause in that comma.”
Experts have delivered a split verdict. “Half the body of forensic linguists doesn’t think that forensic linguistics should be involved in criminal cases,” Hitt said.