Forensic Friday: Forensic Linguistics
Words can betray us. They reveal intention, identity, and sometimes guilt. This week, we're examining Forensic Linguistics, a field that treats language like fingerprints. Every sentence tells a story, and the way we speak or write can serve as evidence in criminal and civil investigations.
What It Actually Is (And Isn’t)
Forensic linguistics is the scientific study of language in legal settings. This includes:
Authorship Attribution: Determining whether a specific person likely wrote a disputed document.
Discourse Analysis: Studying how people speak or write in confessions, witness statements, and court testimony.
Threat Assessment: Analyzing whether a communication poses a real, actionable threat.
Statement Validity Analysis: Evaluating whether a suspect’s account holds up under scrutiny based on language patterns.
It is not literary interpretation, and it’s not a guessing game. When done properly, forensic linguistics uses consistent methodology, reference corpora (large data pile of language, used to compare and verify how people actually talk or write), and peer-reviewed techniques to uncover truth or expose fabrication.
Case Studies Where Language Became Evidence
1. The Unabomber (Ted Kaczynski)
In 1995, Ted Kaczynski demanded that newspapers publish his manifesto or he would continue his attacks. When The Washington Post and The New York Times complied, Kaczynski's brother David recognized the phrasing and writing style from old letters and essays. Phrases like “you can't eat your cake and have it too” helped forensic linguists tie the manifesto to Kaczynski, leading to his arrest in Montana.
2. Derek Bentley ("Let him have it, Chris")
In 1953, 19-year-old Derek Bentley was executed by hanging in the United Kingdom after being convicted of murdering a police officer. Bentley had been arrested with 16-year-old accomplice Christopher Craig during a failed robbery. During the standoff, Bentley allegedly shouted “Let him have it, Chris” before Craig shot and killed a police officer. The phrase was interpreted by prosecutors as a command to shoot, while the defense argued it meant “give him the gun.” Craig, the shooter, was too young for the death penalty. Bentley, though unarmed and intellectually disabled, was hanged at Wandsworth Prison. The case remains one of the UK’s most controversial miscarriages of justice and contributed to the eventual abolition of the death penalty for minors and vulnerable adults. In 1998, Bentley was posthumously pardoned (I guess that helped them sleep at night).
3. Jodi Arias Trial
Arias’s interviews, diary entries, and taped calls were scrutinized for inconsistencies and signs of deception. Forensic linguists and psychologists noted her use of distancing language, excessive vagueness, and sudden shifts in tone. These patterns, along with other evidence, helped prosecutors argue that she fabricated key parts of her story.
4. The Derek Eichelberger Case (2005, Pennsylvania)
In 2005, Derek Eichelberger, a mentally disabled teenager from Pennsylvania, was accused of arson and murder after a suspicious fire killed a family member. He gave a written confession, but forensic linguists found that the phrasing, vocabulary, and even sentence structure matched the interviewing officer's known writing style, not Eichelberger’s speech. The analysis supported claims that the confession had been dictated or coerced. Charges were eventually dropped after this and other evidence undermined the confession’s credibility.
Tools, Techniques, and Modern Uses
Corpus analysis involves comparing a suspect's writing to massive databases of known language to see what stands out.
Stylometry looks at stylistic choices like sentence length, punctuation, and even the use of contractions.
Discourse analysis reveals tone, control, and even bias during police interrogations or cross-examinations.
Machine learning and AI are now being trained to spot patterns in large data sets faster than humans can.
One growing area of use is threat interpretation, which analyzes whether a message (such as a note, email, or social media post) is a genuine threat or just provocative speech.
Linguists look for context, modality, word tension, and specificity. For example, “I could kill him” sounds violent, but may not meet the legal threshold of a threat. “I’m going to kill you at 5 PM tomorrow, at your job,” is different. Courts often rely on linguists to explain where that line lies.
Let’s Discuss
Have you ever seen a case where language told the truth before the person did?
Do you believe forensic linguistics should be used more widely in court, or should it always be supplemental to physical evidence?
How easy is it to change your writing style on purpose? Could you fake being someone else online and get away with it?
Should interrogations always be transcribed and analyzed by a neutral linguist to ensure they aren’t coercive?
Let’s crack this wide open.
-The Emerald Sleuth, reviewing the transcript line by line.
