News organizations across America yesterday carried an Associated Press story about how the police chief of a small town in Tennessee was using polygraphs to “weed out racists” from the hiring process:

Police Chief’s Polygraph Targets Racist Applicants By SHEILA BURKE Associated Press

COOPERTOWN, Tenn. March 8, 2013 (AP) A police chief hired to rebuild a tiny Tennessee department dismantled by scandal is using a lie-detector test to keep racists off his force. Coopertown Police Chief Shane Sullivan took over the department in November, becoming the 11th chief in as many years. He was hired on the heels of a series of police scandals that for a few months left Coopertown with no police at all. Years before that, a mayor was voted out of office after the local prosecutor accused him of racism and running a notorious speed trap. Law enforcement experts say Sullivan’s polygraph approach is unusual, though some departments use the devices for other purposes during the application process. Others try to root out bias in other ways. One polygraph expert warned that lie detectors can’t accurately predict racism for reasons that include people’s inability to recognize their own racism. Sullivan said he doubts racists will even apply for the force if they know about the tests. “I think the polygraph will definitely keep these people from applying,” the 39-year-old chief said. And he believes the policy is working, because he says it’s already discouraged some applicants. “I’ve told a couple of ones about the polygraph who have not called me back.” …

The fact that an applicant didn’t call back after being told about the polygraph requirement doesn’t necessarily mean that the applicant was a racist afraid of being caught by the lie detector. In fact, that is very unlikely to be the case. As the article goes on to explain, the polygraph question is not whether one holds racist attitudes, but whether one has committed a hate or race-based crime. Presumably, very few law enforcement applicants, even those with strong racial biases, have committed such crimes. It’s quite possible that the applicants lost interest for other reasons, such as low pay and poor career prospects with the tiny, trouble-plagued department.

The new chief intends for his lie detector idea to help clean up the Coopertown’s image. Candidates are required to answer whether they have ever committed a hate crime or a race-based crime.

“It doesn’t ask if you’ve ever made a racist remark or slur,” the chief said. Nor does the test ask people if they are prejudiced against any ethnic or religious minority. Sullivan, who has taken the lie detector test himself, said he’s hoping to establish a professional police department that can eventually provide 24-hour service seven days a week. Right now, he doesn’t have the staff to police the town around the clock and leaves those duties up to the sheriff’s office. He’s already hired two police officers, both of whom have passed the polygraph, and he wants to add more. The department’s budget is about $250,000 this fiscal year, Sullivan said, and the chief makes $41,000. Bob Peters, a spokesman for the American Polygraph Association, said asking about factual matters is a better approach than using subjective questions about prejudice or racism. He says a polygraph can’t accurately predict whether someone is racist. “There might be people whom I might think have racist attitudes but they might not think so,” said Peters, whose association has established best practices for use of the polygraph. Peters says the new chief is using the best approach, and some voters are applauding him.

American Polygraph Association (APA) spokesman Bob Peters, is correct that a polygraph can’t accurately predict whether someone is a racist. So why is Coopertown, Tennessee police chief Shane Sullivan attempting to use it for that purpose?

With regard to the APA’s “best practices for use of the polygraph,” note that § 3.3 of its “Model Policy for Law Enforcement/Public-Service Pre-employment Polygraph Screening Examinations” states: “Polygraph test results should never be used as the sole basis for the selection or rejection of a law-enforcement or public-service applicant.” Chief Sullivan’s policy of rejecting applicants who fail the polygraph violates this “best practice.” Maybe APA spokesman Bob Peters should have mentioned that.

“I am very pleased with Chief Sullivan and the effort he is making to create a sound and secure police department for Coopertown,” said Valorie Buck, chairwoman of the Coopertown Community Development Committee. Malik Aziz, national chairman of the National Black Police Association, said the best way to keep bigots from being cops is through extensive background checks. It’s not unusual for police departments to use polygraphs on people before letting them join the force. Police applicants can be asked about past drug use or whether they have been involved in criminal activity. “I haven’t heard of any agency using a polygraph specifically geared toward eliminating racists from the application process,” he said.

In 2005, the Los Angeles Police Department’s pre-employment polygraph screening examination included the relevant question, “Based on your personal bias, have you ever committed a negative act against anyone?” However, it seems that it has been removed from the inventory of relevant questions. But by 2009, that question had been removed from the repertoire.

Of course, any notion that the polygraph could be used to weed out racists from the hiring process would require that the polygraph should actually be able to detect deception. But it can’t. Polygraphy is a thoroughly discredited pseudoscience, and as retired FBI Supervisory Special Agent Dr. Drew Richardson has observed, polygraphers are involved in the detection of deception “to the extent that one who jumps from a tall building is involved in flying.”

Indeed, relying on unreliable polygraphs my actually introduce racial bias to the hiring process. A suppressed 1990 study (1.3 mb PDF) by the Department of Defense Polygraph Institute (now known as the National Center for Credibility Assessment) suggests that truthful blacks are more likely to fail polygraph examinations than truthful whites.

Keeping racists out of law enforcement is a noble goal. Polygraphs are not the way to accomplish it.