New Polygraph Gets Mixed Response
PCASS Allows for Controversial US Army Portable Lie Detector Usage
The Army is trying out a portable polygraph machine with its soldiers to question captured enemies. Some support the new technology while others strongly oppose its use.
U.S. troops over in Afghanistan will soon have a new weapon to use on the battlefield. This month, soldiers will be given portable lie detectors to use when questioning bombing suspects and screening local police, interpreters and allied forces. The new equipment has already been tested in Iraq and the U.S. Army is going ahead with its deployment there.
The PCASS
The new device is being called the Preliminary Credibility Assessment Screening System, or PCASS. It is a hand-held instrument that connects three sensored wires to the hand of the person being questioned. As with full-sized polygraph machines, the questioner asks a series of about 20 questions in either Persian, Arabic or Pashto. The questions start out basic and gradually get to the root of the questioning. The interviewer will type in the answer to each question and afterwards, the screen displays the results. Green means the person has told the truth, red means they have lied, and yellow registers when the machine cannot decide.
The Army has acquired 94 of these machines at $7,500 each. Other branches of the military are looking into purchasing them as well. They were purchased from Lafayette Instrument Co. in Lafayette, Ind. The program inside each devise was created by the Advanced Physics Lab at Johns Hopkins University. They have currently cost about $2.5 million to develop and utilize.
Controversy Over Its Use
The introduction of this new polygraph machine has not been warmly welcomed by some, however. One statistics professor, Stephen Fienberg, conducted a study of the polygraph and disagrees that untrained soldiers will be using the equipment and that the machine has not gone through serious tests and studies. This is nothing new to polygraphs in general. Currently, polygraphs are only used in police investigations and security screenings. They are not used as evidence in most U.S. courts.
These new devices are especially not expected to be as accurate as full-sized machines because the pulse is taken through the fingertips instead of through an arm cuff where both pulse and blood pressure can be measured as opposed to the pulse alone. The PCASS also does not measure the change in breathing and is unable to catch changes in movements that could be used to throw off the machine. The fact that it is easy to use is as much a drawback as it is an advantage because the users of the machine do not go through extensive testing as they do with other polygraph machines.
Support For the Machine
Supporters of the device, however, claims that the PCASS is up to 90 percent accurate when yellow readings are not counted. When these readings are included, hwoever, the tests drop to between 63 and 79 percent accuracy levels. However, this is still better than human intuition alone. Supporters also say that it is not meant to be a stand alone indicator of the truth but rather a temporary tool used for on the spot questioning.
