LINGUISTS HAVE CRACKED TOUGHER CASES

Jack Grieve is most well-known for leading a team that identified the author of the Bixby Letter, a famous 1864 letter sent by President Abraham Lincoln to a mother who ostensibly lost five sons in the Civil War (the letter features prominently in the opening of Saving Private Ryan).

The letter is only 139 words long, but Grieve’s team was able to use a technique known as “n-gram analysis” to determine with virtual certainty that it was actually written by Lincoln’s secretary, John Hay.

Even quotidian sentences can be written a number of different ways. “He’s got a book,” for instance, can also be “he has a book.” “The earth” can be written as “the world.”

N-gram analysis is a way of digitally highlighting all these individual tics in order to compare them against existing writings by suspected authors.

The more tics that line up, the more analysts are confident in identifying a “suspect.” If an investigator was given enough writing samples from White House staffers, Grieve suspects that it would be possible to zero in on an author using n-gram analysis.