A Chicago Tribune investigation found that Chicago police have long ignored voluntary standards for conducting polygraph exams, even as those methods and the examiners themselves have factored into cases costing the city millions of dollars in damages. At least five defendants — four of whom were charged with murder — have been cleared since 2002. In a sixth case, a federal appeals court threw out a murder conviction, leading to the release last month of a Chicago mother prosecuted in the death of her 4-year-old son. The paper suggests Chicago police used their polygraph unit as a tool to obtain false confessions.
Chicago police polygraph examiners have not followed key standards as published by national industry groups when administering the exams, which have long been controversial. The Chicago examiners’ results don’t have to be reviewed by a second examiner or supervisor. The unit has no continuing education requirements in place. And it records only a fraction of its polygraphs. For decades, the department did not use numerical scoring for the tests, even though such scoring is strongly recommended by major industry groups. Police said in 2012 that they had recently moved to numerical scoring. Also, one of the unit’s three examiners said he has not always taken notes in interviews before the tests, though state law requires it.