The CIA, the FBI and other federal agencies are using polygraph machines more than ever to screen applicants and hunt for lawbreakers, even as scientists have become more certain that the equipment is ineffective in accurately detecting when people are lying.
Instead, many experts say, the real utility of the polygraph machine, or “lie detector,” is that many of the tens of thousands of people who are subjected to it each year believe that it works — and thus will frequently admit to things they might not otherwise acknowledge during an interview or interrogation.
Many researchers and defense attorneys say the technology is prone to a high number of false results that have stalled or derailed hundreds of careers and have prevented many qualified applicants from joining the fight against terrorism. At the FBI, for example, about 25 percent of applicants fail a polygraph exam each year, according to the bureau’s security director.
The polygraph has emerged as a pivotal tool in the CIA’s aggressive effort to identify suspected leakers after embarrassing disclosures about government anti-terrorism tactics. The agency fired a veteran officer, Mary O. McCarthy, on April 20, alleging that she had shared classified information and operational details with The Washington Post and other news organizations, a charge her lawyer disputes.
CIA officials have said that McCarthy failed more than one polygraph examination administered by the CIA, but the details surrounding those interviews remain unclear. Dozens of senior-level CIA officials have been subjected to polygraph tests as part of the inquiry, which is aimed at identifying employees who may have talked to reporters about classified programs, including providing information about the agency’s network of secret prisons for terrorism suspects.