Linguistic Lie Detection: A Valuable Investigation Tool
When assessing a witness statement for credibility, common sense goes a long way. So does training and experience in detecting deception. This is one area where you don’t want to get things wrong. People have been wrongly convicted of crimes based on bad attempts at deception detection, and guilty people have been freed for the same reason.
That’s why there is an entire field of study around the skill of detecting deception in written statements.
Unlike techniques used to detect deception in investigation interviews, assessing written statements removes the variables introduced by body language, which can be influenced by culture and language, says Nejolla Korris, an expert in linguistic lie detection and CEO of InterVeritas International. Korris’s firm provides linguistic statement analysis, social media risk training, interview training, investigative services, intelligence gathering and litigation support.
Detecting Deception in Statements
“I might get a police statement or an affidavit of a statement that was given in court, and I’m not able to see the subject,” says Korris. “I’m able to determine whether or not they are telling the truth or where it may beg some more questions because a lot of lies are lies of omission rather than lies of commission. So people will give us signals that lead us to ask more questions about areas that they skip over, for example - especially in written statements.”
The method Korris uses to examine statements is known as SCAN (Scientific Content Analysis), developed by Avinoam Sapir, a former Israeli polygraph examiner. Sapir observed that liars and truth-tellers use different types of language. He used these observations to develop criteria to differentiate between true and fabricated statements.
Some of the basic things look for to detect deception in written statements are changes in pronouns, gaps in time, and evasive answers, says Korris.
To learn more about gathering and assessing evidence in investigations, read 15 Types of Evidence and How to Use Them.
Changes in Pronoun
“If a person says I got up, took a shower, got dressed, I went and had breakfast, we left for work… that change in pronoun tells us right away that there was somebody else. If they don’t say who they are one of the questions we have to ask is who were you with?” explains Korris.
Gaps in Time
“We also look for huge gaps of time. Sometimes if we asked a person what happened: I got up, took a shower, got dressed, I had breakfast, later on I left for work. The ‘later on’ is a clue for us that something happened from the time they were having breakfast to the time they left for work. So we ask them to fill in the gaps,” she says.
Korris also looks for evasion in statements. “When you ask somebody a question and they give you an answer that has nothing to do with your question… they hope that just by virtue of you getting a response that you are going to move onto the next question.” This type of deception can be effective if the interviewer is not listening for the responses and simply skips on, says Korris.
Getting it Right
When detecting deception, there’s always a danger of misinterpreting what someone is saying, and that can be devastating in an investigation. Too often, investigators rely on deception detection tactics to come to conclusions about a witness or suspect.
“Sometimes people have the expectation that it will tell us what the answer is, rather than telling us it’s a clue that we have to probe the person that we’re talking to more,” says Korris. It’s really just a tool, she says, to help investigators develop a line of questioning that will elicit the truth.
Download your free Detecting Deception Cheat Sheet to learn more.