Manny Garcia, Peter Wallsten, and Amy Driscoll of the Miami Herald report of reliance on polygraphy in determining the credibiliy of statements made by an informant. Excerpt:
The Florida Department of Law Enforcement and the FBI are investigating a possible plot to kill Gov. Jeb Bush with a truck bomb in Tallahassee, law enforcement officials confirmed Thursday. . .
The investigators were skeptical. The inmate supplying the information has failed at least five lie-detector tests during the past eight to 10 days conducted by the Secret Service and the FBI. The inmate was specifically asked about the alleged plot against the governor when he failed, prompting some agents to characterize him as “51 percent pathological liar, 49 percent truthful.” He has been jailed since July 2001.
Characterizing someone as a liar or truthful on the basis of polygraph “test” results is foolhardy. Unfortunately, many American law enforcement agencies continue to allow polygraph results to influence their decisions despite the fact that these “tests” are easily beaten and have not been proven to determine truth from deception better than chance in a peer-reviewed study conducted under field conditions.