NCJ Number
110024
Date Published
1988
Length
9 pages
Annotation
The polygraph records certain involuntary changes in body functions that are thought to be indicative of the subject's attempt to conceal the truth.
Abstract
Estimates of the accuracy of this technique range from 95 percent to chance, and the Federal courts generally have refused to admit polygraph examination results into evidence in criminal trials. The advantages and disadvantages of using a polygraph in corruption cases will vary depending upon whether the test subject is a witness or a defendant and upon the outcome of the test (pass or fail). In almost every circumstance, administering a polygraph examination in a corruption case creates factors that work to the Government's disadvantage. If prosecutors or investigators decide to use the polygraph they must abide by the results: if a pro-Government witness fails, they must dismiss the case, cease investigation, or do without the testimony; if a defendant passes they also must be prepared to abandon the investigation or case. Given this and the questionable accuracy and validity of polygraph results, the wise prosecutor in corruption cases generally will proceed as though the polygraph did not exist.