Forensic Linguistics

Forensic linguistics can be useful in court settings.
Basic linguistic knowledge can be valuable.
Linguists can provide evidence in court for various reasons:
- Identifying speakers in a recording.
- Judging the genuineness of a confession.
- Interpreting vague or coded language.

Bomb threat made to Pan Am Airlines.
The defendant, Prince Uvalde, was a baggage handler with a dispute with the airline.
William LeBob was asked to provide testimony for the defense.
LeBob compared a recording of the bomb threat call with a recording of Prince Uvalde saying the same phrase.
LeBob found that the bomb threat caller had a New England accent, while Prince Uvalde had a New York accent.

Spectrograms visually represent what the tongue is doing in the vowel space.
The vowel quadrilateral shows the position of the tongue when making different vowels.
Analysis of the word "off" showed differences in vowel placement between the caller and the defendant.
Analysis of the words "five" and "die" also showed differences.
These differences indicated that the speakers were not the same person.

The prosecution questioned whether Prince Uvalde could be imitating a New England accent.
LeBob argued that imitators focus on socially relevant features (marked words and sounds) but not the underlying phonological structures.
The bomb threat caller had a perfect reproduction of the Boston sound system, which is unlikely to be imitated perfectly.
Prince Uvalde was acquitted.

A man was accused of killing his wife, but no body was found.
An unsigned typewritten six-page letter claimed the wife had left to live with another man.
The crucial question was who wrote the letter.
The police compiled a corpus of texts:
- The farewell letter (2,500 words, typewritten).
- The husband's writings (3,500+ words).
- The wife's writings (3,300 words).
The husband had weaker literacy skills than the wife.

Non-marking of person -s: Occurred in the husband's corpus and the farewell letter (e.g., "believe" instead of "believes").
Present and past confusion: Occurred in both the husband's corpus and the farewell letter (e.g., "because they believe me" rather than "believed me").
Spelling errors, syntactic errors, and punctuation errors frequently appeared in the husband's text and the farewell letter but not at all in the writing of the wife.
The analysis indicated that the husband wrote the letter.
The husband initially maintained his innocence but then pleaded guilty to manslaughter.
Simple corpus analysis revealed patterns in the way people write.

A bribery case was a spin-off from a larger FBI operation.
Recordings were made covertly over months.
Recordings were dubious, frequently turned on and off, and some tapes were erased.
The hypothesis was that Paul Manziel was willing to pay to get out of completing community service for a drunk driving conviction.
The key question was whether Paul was aware of the plan.

It is easy to tell if someone is present if they are talking.
It is harder to tell if they are present but silent.
Clues to determine presence:
- Greetings or farewells (e.g., "Hello, Paul").
- Pronouns (using "you" or "your" if present, "he," "she," or "they" if not).
- Hearing their voice in the distance talking to someone else.

The plan for the bribe was discussed at a normal volume, and "his" and "he" were used to refer to Paul.
The informant loudly called out to Paul.
Paul's voice became louder, and footsteps were heard, suggesting he was further away and coming closer.
The recording appeared to be doctored.
The evidence suggested that Manziel was not present at the key moment.
The case was dropped before trial.
Lateral thinking about language and discourse can help solve such problems.

Forensic linguistics can be valuable in various legal contexts.
Even a small amount of linguistic knowledge can be helpful.
Future topics in grammar and discourse structures will be covered in the next semester.