Device Helps Police Zero In On Suspect
An apparatus called the computerized voice stress analyzer test (CVSA) is helping some police departments focus more closely on potential suspects. CVSA is intended to gauge the stress in a person’s voice based on vibrations to indicate whether he or she is lying or not.
The system works by recording voice responses during an interview using a microphone; the questions typically have yes or no answers. Patterns that produce pointed peaks suggest that a person is probably being truthful, while a pattern resembling a nearly solid square indicates possible dishonesty.
Detective Dala Milosavljevic in Cudahy, Wis., says his police department has been relying on CVSA since 1998 for robberies, murder cases, and other crimes. He says it is crucial to follow instructions and implement what was learned during training.
The manufacturer of the device, the National Institute for Truth Verification (NITV), believes that such a failure to follow directions probably was a factor in a California case where three teens falsified their confessions about a stabbing death. NITV’s insurance firm agreed to a settlement in conjunction with the case, even though NITV objected, says Bill Endler, the firm’s director.
He said CVSA now plans to conduct a study based on police departments’ data in an effort to resolve questions about CVSA’s reliability.
The devices cost about $13,000 each inclusive of training, compared to about $25,000 for polygraphs, says CVSA.
Abstracted by the National Law Enforcement and Corrections Technology Center(NLECTC) from the Milwaukee Journal Sentinel (05/14/06); Spice, Linda .
