Frequently Asked Questions about Polygraph Examinations
(Questions about what to expect during a polygraph examination are answered)

American Polygraph Association website answers to frequently asked questions
about using polygraph in credibililty assessment.

Validity & Reliability of Polygraph Testing
The American Polygraph Association believes that scientific evidence supports the high validity of polygraph examinations.

Research on Voice Stress Analysis (VSA)
"Validity of voice stress measures was poor."

APA Code of Ethics
American Polygraph Association membership Code of Ethics.

Polygraphs Can Be Admissible in Court
Polygraph Quick Reference Guide to the Law (APA)

SAN DIEGO -- A former San Diego police officer accused of raping a prostitute has passed a polygraph test supporting his defense, according to information obtained by 10News. Dan Dana, 26, was ordered to stand trial in June after a 35-year-old woman claimed he raped her in Presidio Park while he was on duty. William Wolfe, Dana's attorney, said Dana was specifically asked if he forced the woman to have sex. When he responded with "no," the polygraph showed Dana was telling the truth, according to Wolfe. When asked what was the point of the polygraph test when it is likely not admissible in court, Wolfe said, "When you have a case that boils down to his word against hers, what could be more telling - whether it's admissible or not -- than he passed a polygraph examination as to the claims she's making?" Wolfe said he will turn over the full polygraph results to the district attorney's office in hopes the case against Dana will be dropped. Dana faces more than 17 years in state prison if convicted of rape under the color of authority, oral copulation under the color of authority, false imprisonment and assault by an officer.

Source: www.10news.com January 2012

A polygraph test is not usually admissible in court, but it sure came in handy for a King George County suspect. Robbery and firearms charges against 19-year-old Dontrell Terrance McCreary were dropped yesterday in King George Circuit Court, largely because McCreary passed a lie detector test. McCreary is already serving a 12-year prison term for his role in a series of armed robberies in Stafford County between Feb. 1 and March 4 of last year. All four robberies occurred in North Stafford, and a man was shot in the shoulder during one of them. McCreary, whom Stafford authorities named as the shooter, was also charged with a Dec. 21, 2009, robbery in King George. King George Commonwealth's Attorney Matt Britton said that while McCreary confessed to his activities in Stafford, he adamantly insisted he was not involved in the King George incident. Britton said the victim was not able to positively identify McCreary in two photo lineups but eventually did identify him after seeing his picture in a newspaper. Britton said McCreary also had alibi witnesses for his whereabouts on the night of the King George incident. Britton said he finally struck a deal with McCreary's attorney in which McCreary would plead guilty if he failed a polygraph exam but the charges would be dropped if he passed. He passed. In Stafford, McCreary pleaded guilty to two counts of robbery, malicious wounding, conspiracy and using a firearm in the commission of a felony. He was sentenced to a total of 33 years in prison with all but 12 years suspended. McCreary and Julio Mayes were arrested and later convicted after a victim in one of the Stafford robberies recognized one of them from high school.

Source: http://fredericksburg.com December 2011

MITCHELL COUNTY - New details involving missing Colorado City teen Hailey Dunn. Clint Dunn, Hailey's father, tells NewsWest 9 he took a polygraph test and passed. While the Mitchell County Sheriff's Office could not release the results of that test, they did confirm he was cleared as a suspect. According to Clint Dunn, his girlfriend also passed a polygraph test. Hailey has been missing since December 27th. Her mother's boyfriend, Shawn Adkins, remains the only person of interest in the case.

The suspect in the brutal beating of San Francisco Giants fan Bryan Stow has taken two Polygraph tests in the last two days, and a polygraph expert for the defense team hinted Wednesday night that he has passed. Giovanni Ramirez, 31, was arrested May 22 following an intensive investigation into the beating outside Dodger Stadium. Stow was attacked by two men as he left the stadium, suffering grievous injuries. The 42-year-old paramedic remains in critical but stable condition under heavy sedation to prevent seizures caused by traumatic brain injury. Shortly after his arrest, Ramirez demanded a polygraph test, his attorneys said. Even though results of lie detector tests are seldom admissible in state court, one of Ramirez's attorneys Jose Romero said he hoped the move would convince prosecutors not to press charges. The defense team administered a polygraph Tuesday night at the Men's Central Jail and police carried out their own test Wednesday.

Source: http://www.sfexaminer.com October 2011

A Brighton woman charged with stealing her alleged lover's wife's jewelry and coins from a bank safe-deposit box is "100 percent innocent," a police sergeant said Friday. The Livingston County prosecutor's office dismissed all charges lodged against Maria Ann Parker, according to court documents. "We had a lot of evidence to show that she was innocent," defense attorney Vincent Farougi said. "She had essentially passed the handwriting analysis. They didn't find her fingerprints on the safe-deposit box. She passed a private polygraph, but it wasn't until I spent about three hours at the bank going through their signature-card records that I found a signature card that matched, or closely matched, the signature on the card of the Mojdah Daniels safe deposit box." Multiple messages seeking comment from Prosecutor David Morse were not returned. However, Michigan State Police Detective Sgt. Sean Furlong confirmed Friday that his investigation proved Parker's innocence. "In my 21 years, I've never had someone completely innocent; Miss Parker is completely innocent," Furlong said. Parker was charged in May 2010 with identity theft and larceny in a building. Although prosecutors dropped the charges of identity theft, she was bound over to Circuit Court for trial after Daniels testified at a preliminary hearing in October that she recognized Parker in bank surveillance photographs as the woman believed to have been given unauthorized access to Daniels' safe-deposit box in March 2009. Daniels claimed in court her husband fired her from his orthodontist practice after she learned her husband and Parker "were having an affair." Daniels also testified that she discovered a pearl-and-diamond necklace as well as 50 gold coins missing from her safe-deposit box at the former National City Bank in Brighton in September 2009. She said she was surprised to find that someone had opened the box, which she discovered when she noticed an unfamiliar signature on the bank card used to gain access to the box. Furlong said the woman in the bank surveillance photos is not Parker, but another bank customer who went to the bank that day to access her personal safe-deposit box. However, a bank representative inadvertently pulled the wrong signature card, which the customer said she signed without noticing if it was her card, Furlong said. "It's not until three months later that Miss Daniels enters her (safe-deposit box) and sees an unknown signature," the detective sergeant explained. "She makes a complaint believing it's Maria Parker, but Maria Parker is 100 percent innocent in this charged crime. "Miss Parker went through a long agony over this," Furlong added. Farougi said the missing items have since been accounted for. He said the whole ordeal has been upsetting for his client, who "had her life on hold for more than a year." During that time, Parker was denied an opportunity to attend college out of state because of bond conditions. "Her life was materially affected the whole process," Farougi said. "In order for the criminal justice system to work, people have to be honest. They cannot use the system for their own selfish needs."

Source: www.livingstondaily.com September 2011

The suspect in the brutal beating of San Francisco Giants fan Bryan Stow has taken two Polygraph tests in the last two days, and a polygraph expert for the defense team hinted Wednesday night that he has passed. Giovanni Ramirez, 31, was arrested May 22 following an intensive investigation into the beating outside Dodger Stadium. Stow was attacked by two men as he left the stadium, suffering grievous injuries. The 42-year-old paramedic remains in critical but stable condition under heavy sedation to prevent seizures caused by traumatic brain injury. Shortly after his arrest, Ramirez demanded a polygraph test, his attorneys said. Even though results of lie detector tests are seldom admissible in state court, one of Ramirez's attorneys Jose Romero said he hoped the move would convince prosecutors not to press charges. The defense team administered a polygraph Tuesday night at the Men's Central Jail and police carried out their own test Wednesday.

Source: www.sfexaminer.com August 2011

A man accused of killing a Farmers Branch police officer 27 years ago walked out of jail a free man on Tuesday. There was a big hug for Gary Pettigrew from his companion. Earlier this month, the Dallas District Attorney dropped the case against him, saying they don't have the evidence to convict him. The free man was released carrying all his belongings in a paper bag. He says he believes his arrest was politically motivated by the DA's office. "Because they did not have any more evidence than they did before, except a guy who told them something that wasn't credible," said Pettigrew. "He was an ex-convict trying to knock some time off his time." Pettigrew maintained his innocence and even turned down a plea bargain. He also passed a polygraph test. District Attorney, Craig Watkins has declined interviews about this case with News 8 but says the case remains open. Pettigrew says he just wants to get back to his life now.

Source: www.wfaa.com July 2011

Woodland Hills, CA, /PRNewswire/ -- "Almost no human being can beat a polygraph test," says Dr. Louis Rovner, a noted psychologist and polygraph expert in California. In fact, lie detection technology has become so sophisticated that a polygraph can now detect a person's efforts to try to beat the test.

In a recent Deputy Sheriff Magazine article, Dr. Rovner writes that there are several books and pamphlets available on the Internet which claim to teach people how to beat a polygraph test. None of these, he says, can do what they claim.

Dr. Rovner feels that the idea of beating a polygraph test after reading a short book is absurd. "This is about the same as saying that you will be able to perform a Beethoven Piano Concerto at Carnegie Hall by simply reading a book about piano playing." The interplay between the sophisticated technology of the polygraph, the experience of the examiner, and the involuntary physiological reactions of the subject is so complex that almost no one can look truthful on the polygraph when he is actually lying.

"Beating the polygraph," says Rovner, "is impossible for most people." The polygraph is a scientific instrument which records physiological changes in our bodies. Polygraph examiners are trained to look for subtle abnormalities in these changes as a person answers a series of questions. The changes are involuntary reactions that occur in our bodies when we are not being truthful. "In order to beat the test," he says, "a person must use his central nervous system to override the involuntary activity of the autonomic nervous system, and he must do it on cue." Given the anxiety of a typically polygraph subject, it is extremely unlikely that anyone could successfully fool the polygraph.

Scientific research into polygraph accuracy has been going on for more than 40 years. "Overall," says Dr. Rovner, "we are confident that polygraph tests have a 96% accuracy rate when done properly." That statement is backed up by hundreds of research studies and experiments. Rovner's own published research shows that people cannot beat a polygraph test simply by reading about it.

Source: Rovner & Associates