American Polygraph Association website
answers to frequently asked questions
about using polygraph in credibililty
assessment.
(Click on the subject title to retrieve the information.)

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)

LIE DETECTION IN THE
NEWS:

Polygraph Clears Suspect in '06 Death

Kevin L. Mullins said he was unconscious when someone fatally shot Lowell Baker in a North Side apartment in 2006. That didn't sway police, who arrested him in the slaying. But Franklin County prosecutors dismissed the murder case against Mullins this week based on the results of a polygraph examination. "He definitely passed the polygraph," Assistant County Prosecutor Sue Ann Reulbach said. Mullins, 29, was arrested nine days after the Aug. 28, 2006, shooting of Baker, who was found dead in his kitchen at 5740 Arborwood Court, Apt. D. Police said Baker, 24, died in a dispute over drugs. Mullins told investigators that he and two other men went to the apartment to get their money back after Baker sold them bad drugs, Reulbach said. When the apartment door opened, Baker struck Mullins in the head with a hammer, knocking him out. Witnesses reported seeing two suspects carrying a third man away after shots rang out. A trail of blood in a nearby parking lot led police to theorize that one person was injured. Prosecutors dropped all seven charges against Mullins, including aggravated murder, aggravated robbery and aggravated burglary.

Source: www.columbusdispatch.com April 2008

Death of Monticello Teen Ruled Accidental

MONTICELLO - Authorities say 17-year-old Reggie Rios Costello died accidentally. Costello's body was discovered Feb. 27 partially emerged from a basement hatch door outside of a house in the village of Liberty. "There is no evidence of any criminal involvement in the manner in which Rios (Costello) was found," District Attorney Steve Lungen said during a news conference today. "As a result of our findings there are no criminal charges being brought against anybody." Costello, who lived in Monticello, went to the home at 46 Chestnut St. to buy marijuana, and then got into a fight in the hallway with Angelo Dion Johnson, 32, a resident of one of four apartment homes in the complex. Johnson had sold Costello a small amount of marijuana. Authorities speculate that Costello wandered down in the basement after the fight, and then tried to leave the home through the hatch door. It is unclear why he went down there, however. That door was weighed down with snow. Costello got trapped, strangling himself, Lungen said. Lungen said the investigation focused on Johnson. That man's DNA was found on Costello's jacket and pants. Johnson told authorities that he did get into the fight, but that he was unaware that Costello was in the basement or how he got there. He passed a polygraph. There was no evidence of any struggle in the basement.

Source: www.recordonline.com March 2008

Petro Helps Convicted Rapist to Get New Trial

DAYTON, Ohio -- Ohio's former Attorney General Jim Petro is trying to help a man from the Miami Valley get a new trial. Petro filed a motion in Montgomery County Common Pleas Court on Wednesday on behalf of Roger Dean Gillispie. The Ohio Innocence Project is also assisting in the case. After two trials, Gillispie was convicted in 1991 of kidnapping, raping and robbing two women near the Dayton Mall in 1988, but he and his parents have always maintained his innocence. There is no DNA evidence linking him to the case, only witness identification. Petro said Gillispie even passed a lie detector test given by a top polygraph examiner in the state. Gillispie is serving a 15 to 50 year prison sentence at the London Correction Institution. He has already served 17 years.

Source: www.whiotv.com February 2008

Former Tobias Assistant Says He Passed Polygraph Test

Jupiter, Fla. -- A key witness in the Seth Tobias death investigation says he has passed a polygraph test when questioned about his claims that Tobias' wife had a hand in her husband's death. Billy Ash, who claims he was an assistant to CNBC commentator Seth Tobias, has said for months that Tobias' wife, Filomena Tobias, drugged the former hedge-fund manager and drowned him in the couple's $2 million Jupiter mansion pool in 2005. Ash said Filomena was the cause of her husband's death, but Filomena's lawyers have repeatedly questioned the validity of Ash's claims, pointing out Ash's previous arrest record and his past career at an escort agency, WPBF News 25 reported. Court documents from 2003, however, display accusations of Filomena's alleged violent past during her second marriage, one to attorney Jay Jacknin, WPBF reported. Seth Tobias's brothers claim in their probate case that Filomena drowned her husband to get his $25 million fortune. Filomena and her lawyers have since denied any such claim as to her role in her husband's death.

Source: http://www.wpbf.com January 2008

Mike Shanahan Says Travis Henry Passed Polygraph, Hair Test

Broncos running back Travis Henry is in the process of appealing a positive test for marijuana, and because Henry is a repeated violator of the NFL's substance-abuse policy, he'll be suspended for a year if he loses his appeal. But Broncos coach Mike Shanahan is suggesting that the league's drug-testing procedures may have gone too far this time. According to Shanahan, the team administered a lie-detector test to ask Henry if he had used marijuana, and it tested a hair sample as well. Henry passed both tests. "If the tests were positive, Travis would not be on our football team right now. When he went back and took the hair sample and that was negative; the lie detector test and that was negative; we'll let due process take care of itself," said Shanahan at his weekly press conference. As Pro Football Talk notes, Shanahan is essentially saying there's a major flaw with the league's policy of using urine tests to determine whether a player has violated the substance-abuse policy. If Shanahan thinks the Broncos' lie-detector and hair tests are superior to the league's urine tests, I hope he's also urging the league to abandon urine testing as the sole means of determining whether a player used drugs.

Source: http://sports.aol.com November 2007

Trial is Delayed for Polygraph

WARREN - A judge Monday delayed a murder trial to allow the defendant time to take a polygraph exam that could clear him of the charges. William Keith Gunther, who was linked this year to a 13-year-old murder through a state DNA databank, has told his attorney he had sex with the victim, but did not kill her. Gunther, through his attorney John Fowler, agreed to a polygraph exam in which the results can be used as evidence in a future trial. Gunther's trial had been scheduled to start Monday but now has been delayed at least 90 days by Trumbull Common Pleas Judge W. Wyatt McKay. Gunther, 35, is accused in the rape and murder of Priscilla Code Jan. 15, 1994. Her murder had remained unsolved until a crime lab this year came up with a DNA match in the case. Gunther was arrested in the Miami area earlier this year. The indictment against Gunther includes firearm specifications on both the murder and the rape, which is how police were able to match DNA to Gunther. A statewide databank links up with a national databank that includes more than 2 million known offenders and forensic profiles from nearly 100,000 cases, including those that are unsolved.

Source: http://tribune-chronicle.com October 2007

Polygraph Unbeatable, Says California Psychologist.

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