The Cassville Police Department received the latest version of the Computer Voice Stress Analyzer (CVSA) in August. Lt. Danny Boyd, who attended a special training certification class for the operation of the device, uses the device to assist all southern Barry County law enforcement officers, including the Barry County Sheriff's Office.
"It is a very, very useful tool for investigations," said Boyd. "It saves a lot of man hours interviewing people. With this device, we can perform a test within an hour to help direct an investigation."
The CVSA, which operates on a laptop computer, analyzes audible responses to yes and no questions in order to determine if an interviewee is telling the truth or being deceptive.
Boyd has been certified to use a CVSA system for four years. He attended a one-week class in Boone County for his initial certification and recently completed a three-day re-certification course at Port Arrowhead in Lake of the Ozarks. Officers must be certified every two years.
During the training course, officers learn how to read the graphs developed by the CVSA device. They also learn how to ask the right questions in order to obtain information that will be helpful in investigations.
"We spend a lot of time learning to read the graphs and how the machine works," said Boyd.
During training sessions, instructors use a guitar to demonstrate how an individual's voice produces different sound waves when the person is telling the truth or being deceptive.
"This device can be used on any case," said Boyd. "We have used it on several cases involving stealing, child abuse and even rape cases. We can use it on anything that comes through the department."
Boyd often spends around 30 minutes with an interviewee prior to using the CSVA device. The pre-interview is used to develop proper questions for the CSVA device, which analyzes an interviewee's responses as Boyd asks a series of yes or no questions.
After the CSVA device is used, Boyd shares the responses with the interviewee.
The CSVA device can be used to conduct interviews in person or over the telephone. It also allows officers to print a report with the interview information, including the questions and the graph reports, which can be included in an individual's case file.
The CSVA is not only used by law enforcement personnel. Boyd said that many companies are beginning to use the device in the pre-employment screening process.
"This requires less time and money than the traditional polygraph system," said Boyd. "It is a great investment for any law enforcement agency."
The CSVA device was purchased using capital improvement funds.