Most people get a better sense of a person when meeting them face-to-face. The person sitting across from us in an interview may steeple their fingers in a show of confidence or cross their arms over their chest defensively. But interviewing someone over the phone is more challenging because you can’t see the person and how they react to your questions—all you have to go off of is their voice.
But there is a way for law enforcement to analyze the truthfulness of suspects or witnesses via the phone. The Computer Voice Stress Analyzer (CVSA®) is a truth verification system that can be used with either a live telephone call or a recorded call to ascertain deceptive answers. Whether you are using a semi-structured interview methodology or a structured covert interview format, you need to verify the accuracy of the answers you are hearing. Recording those interviews gives you the edge because you can listen to the call numerous times, check for discrepancies, and analyze the CVSA charts in order to combat the ease of lying over the phone.
The Unique Challenges of the Telephonic Interview
Sometimes, the telephone is the only way to get information. When a person calls in a tip about a crime anonymously, it helps to know if this is a crank call or if they are presenting genuine information. And in a range of other types of cases—including kidnappings, fraud committed over the telephone, sex offenders or human traffickers, and hackers who use social engineering to obtain information—the telephone may be your only point of contact with suspects at the beginning of the investigation. Sometimes, a criminal investigation leads you to overseas sources, and, again, the telephone interview is the best way to make contact as quickly as possible while avoiding a lot of the red tape and lowering the impact on police resources.
However, such cases pose special problems for law enforcement. When you are talking to someone only using audio, they could easily lie about their identity or location, unless you are able to trace their call. Is there anyone else is in the room, perhaps feeding them information? That is also difficult to ascertain.
A number of studies have shown that lying on the telephone is common because of how easy it is. Cornell University researchers conducted a study involving 30 students. For a period of seven days, the researchers monitored the student’s social media and telephone interactions. They discovered that 37 percent of their telephone conversations included lies, while only 27 percent of their face-to-face interactions were deceptive. Lead researcher Jeff Hancock, Assistant Professor of Communication, concluded that people are less likely to lie if they know the conversation is recorded or documented. Given this information, it is reasonable to be suspicious of any claims received over the telephone.
How to Determine Truthfulness over the Telephone
While there are verbal cues that give away whether someone is being deceptive, it is inadvisable to rely on your perception alone, no matter how well trained you are in picking up these cues. In another study, researchers from the University of Portsmouth in the U.K., including Aldert Vrij (renowned for his work in studies on deception), conducted two studies measured by Criteria-Based Content Analysis (CBCA) where mock insurance claimants were interviewed over the phone by insurance company staff. They had a 50 percent success rate at determining which of the claimants were lying. In a second study, some of the participants listened to a model statement about an event that was truthful and unrelated to an insurance claim. Those who listened to the statement and told the truth scored higher on the CBCA than those who lied, but only those who told the truth and listened to the model statement sounded more believable than the liars. Essentially, statement analysis techniques such as CBCA may help investigators look for verbal cues in an individual’s statement, but while there appears to be a positive impact on an investigator’s ability to determine truthfulness using this technique, there are still too many variables for accurate results.
In contrast, a truth verification system such as the CVSA provides a technological analysis for determining deception in a telephone interview. The CVSA picks up verbal cues unidentifiable by the human ear, thus allowing investigators to analyze parts of speech that would otherwise be inaccessible to them otherwise. Law enforcement agencies receive hundreds of calls a day through emergency lines or crime specific tip lines, so vetting the most important of these calls could save many investigative hours and perhaps even a life.
Unlike the polygraph, which requires face-to-face contact, the CVSA can be used in covert recordings of telephone conversations or live telephone calls. The CVSA is particularly useful when conducting structured covert calls because you can also access notes, a template, or other formal strategies during the interview. This ability is especially important for cases where questions must be asked in a certain order or detailed information is required.
When presented with criminal evidence disseminated over the phone, it’s important to work with more than intuition, human identified verbal cues, or techniques such as CBCA to prove the validity of statements. People lie easily when they can hide their faces, but the CVSA transforms their voices into clear, readable charts indicating deception. The information contained in these charts speaks louder than any words that come across the phone line.
Please reach out to us at NITV Federal Services to learn more about our CVSA systems and training programs.