Polygraphs have both criminal and civil applications: 

1. Criminal Investigation

   If a pool of suspects is large, the polygraph can help to eliminate people and narrow the field.  It can also be used during interrogation to elicit confessions.  Whenever polygraphs are used with suspects, they must be advised of their rights and their attorneys must be present to witness any waiver of their rights.

   The wording of the test questions is generally devised between the investigator and the polygrapher, based on the facts of the case.

   Informants, such as jailhouse snitches, may also be subjected to a polygraph to help determine the reliability of their statements.

   The same is true of some potential witnesses. 

2. Employment Screening

   After the fifties and up until the government took action in 1988, more then 80 percent of polygraph tests given were for this purpose.  Potential employees were asked about past dishonesty and criminal behavior in order to avoid hiring people who might damage the company.  Then its use was banned under the Federal Employee Polygraph Protection Act (EPPA), except in government jobs, companies that manufactured or dispensed drugs, and companies that do sensitive work on government contracts.  Under this law, an employer in a private business can ask an employee to take a polygraph only if the employer provides clear documentation of his or her suspicions, and the employee may not be fired only on the basis of polygraph results.

   The FBI administers some 5000 polygraphs a year for people entering sensitive jobs, with each applicant taking two separate tests with different types of questions.

   Since the 1950s, the polygraph has been used extensively for applicant screening in police departments.  Some 25% are disqualified based on polygraph information, such as illegal drug use, employment dishonesty, and involvement in felonies.

3. Civil Litigation

   Violations among private citizens and businesses taken through a legal procedure in the civil arena are punishable with monetary awards.  These include personal injury, property damage, intentional misconduct, and breaking contracts.  Polygraphs may be used on witnesses or suspects, as long as there is no violation of the EPPA. 

4. Post-conviction Sex Offender Testing

   Polygraphers go through specialized training for this in order to be able to interview subjects and attend to cognitive processing that can be unique to some types of offenders. 

James Calams, of Calams & Associates, Ltd., is a professional polygrapher based in Phoenix Arizona. (Jcalams@cableone.net).  With fifteen years of experience as a police officer and twenty as an investigator in which he developed a program to track roving criminals, he now works fulltime doing polygraph testing.  Most of his work involves pre-employment, certification, and "specific issue" testing for police departments, although he also works in private industry.  

"Specific issue testing," he explains, "is about a single incident or issue, such as a police officer involved in excessive force, theft, or some other kind of crime.  Recently I was hired by a battery company that was missing $123,000 worth of merchandise.  I tested all of the employees on that issue."

He points out that someone may be guilty of a crime but still pass a polygraph test.  "A lot of it has to do with your conscious and subconscious psychological set and the type of admissions you make."  The accuracy rate for pre-employment testing, he estimated, was 72-78 percent, while specific issue testing is better, at 80-90 percent.

"You're talking with someone about their entire lives, from the day they were born to the day they're sitting with you, and you have control questions prepared to compare against the relevant questions.  If the person stole money, the relevant questions will all pertain to money, and the control questions are questions about their earlier life histories."

To conduct a good polygraph test, Calams says, you have to be a good interviewer.  "In my police training, I got to talk to people from all different walks of life.  I don't put myself above anyone and I can talk to anyone.  There are three things that I need to do as an interviewer: get information, give information, and make a friend.  That's how you get people to talk.  If you can do that, you're job is done."

Although polygraph testing has become much more accepted in the scientific community, its use in court is still viewed with suspicion.

In a 1998 case, United States v. Scheffer, the U. S. Court of Appeals for the Armed Forces decided that President Bush's decision to ban all use of polygraphs from military courts was unconstitutional.  It was appealed to the Supreme Court, which ended up in a complex legal situation. They reviewed the studies and left the decision as to whether or not to admit polygraph evidence up to each jurisdiction.  Any court can decide to exclude it per se (under any circumstances) or to evaluate it case by case, according to the ruling in Daubert that it has a reliable scientific foundation.  The polygraph appears to compare favorably with evidence like fiber analysis, ballistics comparison, and blood analysis, all of which have become standard court procedures.

One reason for using a polygraph result in court is to bolster the credibility of witnesses by showing them to be non-deceptive.  Another is to impeach the credibility of a witness.  However, once allowed, litigants may try to introduce such readings for most or all witnesses, and then experts would be called in for some, substantially increasing the length and cost of cases.  

Even with the imperfect accuracy rates, the polygraph is superior to the ability to detect deception through observation or statement analysis by even the most experienced professionals.  The question, however, is whether it is the best device on the market.  Let's look at another that has been offered as its own form of lie detection.