‘…[I]t turns out in some of the world’s most baffling criminal cases—notorious kidnappings, domestic terrorism, thinly veiled threats and collusion, false confessions, mysterious deaths—it was not the chance appearance of some wayward DNA, CSI-style, that finally cracked the code, but some seemingly harmless point about language.
Strange to think that a handful of mere words, short of a blatant confession, could end up pointing the finger at unknown perpetrators of a crime. Perhaps like DNA, words and the ways we use language can potentially reveal features of ourselves, our intentions, and our actions, left hastily at the scene without our being aware of it.
It’s thanks to the quirky use of idioms, oddly-placed punctuation, vocal tics, and certain other idiolectal, dialectal and stylistic markers, that anonymous speakers and authors have often been identified. Linguistic evidence left behind in wire taps, ransom notes, texts, tweets, and emails, (and even pet parrots!) has sometimes led to major breakthroughs and even the resolution of many famous cases. Just like DNA analysis, however, these linguistic markers have to be used cautiously in a forensic context.
Source: JSTOR Daily