Wednesday, the Tennessee Bureau of Investigation announced its Polygraph Unit has been awarded accreditation through a national board, Polygraph Law Enforcement Accreditation (PLEA).

In case you have never heard exactly what a polygraph machine is used for, it helps to detect and record changes in physiological characteristics, such as a person's pulse and breathing rates, used especially as a lie detector.

The process, which began in October 2014, required an extensive review of TBI's policies and practices guiding its Polygraph Unit, which currently comprises four polygraph examiners and a supervisor, all of whom are TBI Special Agents. During the accreditation process, volunteer inspectors from several law enforcement agencies across the country worked alongside TBI's personnel to ensure TBI's policies regarding examination techniques, quality control, reporting, and training were up to the highest-possible standards.

"We are pleased to provide this level of service to support our investigations and those of our partner agencies across Tennessee," said TBI Director Mark Gwyn. "Accreditation demonstrates our agency has done everything possible to ensure we operate at the highest, most widely accepted standards."

Accreditation through PLEA was only available to law enforcement agencies beginning in 2010. Currently, 12 agencies have achieved this distinction, including police departments in Los Angeles and Houston, the Florida Highway Patrol, and the North Carolina State Bureau of Investigation.

PHOTO BELOW: From L-R: TBI Deputy Director Jeff Puckett, North Carolina State Bureau of Investigation Special Agent Amanda Nosalek, TBI Director Mark Gwyn, TBI Assistant Special Agent-in-Charge Skip Elrod, TBI Deputy Director Jason Locke