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Published October 06 2013

Police and polygraphs: Metro agencies use lie detectors as an investigative tool

FARGO - Rollie Rust admits he wasn’t a big believer in lie detectors before he went to polygraph testing school.

But after more than three decades of quizzing suspects and other subjects for truthfulness, the retired Fargo police sergeant has concluded that, if used as intended, the polygraph test is “just really kind of a nice tool.”

“Being in this profession for 30-some years, I’m really comfortable with it,” he said. “But I’m comfortable to the point I know that you don’t try the whole case just by the polygraph.”

Lie detector tests have played a role in two recent high-profile murder cases in the region.

According to court records in Otter Tail County, Minn., a father and son charged with killing their relative, 33-year-old Scott Burris, reportedly over drug money he owed them, had failed lie detector tests administered by law enforcement early on in the investigation.

A polygraph exam also was administered to Travis DuBois Sr., the father of two young children murdered in their home in St. Michael, N.D., in 2011. During the test and interview with FBI agents. DuBois confessed to killing the children but later recanted, and another man, Valentino “Tino” Bagola, was convicted Sept. 23 of the stabbing deaths.

Officials with law enforcement agencies in Cass and Clay counties all said last week they use lie detector tests in criminal investigations, though not often. The Fargo Police Department also uses the test in the pre-employment screening process.

How it works

Scientists generally agree there is no bodily response uniquely associated with lying, so a polygraph test measures three indicators of involuntary arousal: breathing, heart rate/blood pressure and skin conductivity, or the sweatiness of the subject’s fingertips, according to the American Psychological Association.

A blood pressure cuff goes on the subject’s arm to detect changes in cardiovascular activity, while rubber tubes called pneumographs are wrapped around the person’s chest to measure breathing rate and depth. Electrodes on the fingertips measure skin conductivity.

According to the APA, the most widely used test format in criminal investigations is the Control Question Test, which compares responses to relevant questions such as “Did you shoot your wife?” to responses to control questions.

The accuracy of polygraph tests remains a controversial subject, but Rust said there have been advancements in the field through the use of computers and software and the development of industry standards.

Investigative tool

Rust was the Fargo Police Department’s in-house polygraph examiner from 1979 until his retirement in 2000. He continued to provide tests part time for the department until 2008.

Rust now works on a contract basis for the West Fargo Police Department, which uses polygraph tests “strictly for investigation purposes, to help eliminate possible suspects, things like that,” West Fargo Police Lt. Duane Sall said.

Lt. Joel Vettel said the Fargo Police Department now contracts for polygraph services with Orie Oksendahl, who has worked as a special agent for the Minnesota Bureau of Criminal Apprehension.

Like Sall, Vettel said the test can be helpful when trying to narrow the suspect pool.

“It gives them a little bit more clarity … in trying to establish the credibility of statements made by individuals in the interview process,” he said.

The Moorhead Police Department and Clay County Sheriff’s Office both rely on the BCA for lie detector tests.

Clay County Lt. Steve Landsem said he couldn’t recall using a polygraph test in a case in nearly 10 years. Sometimes, just to see how the person will respond, investigators will ask, “Just to make sure you’re not a suspect, would you take one?” he said.

Moorhead police have applied polygraph tests in some theft and assault cases, but not often, said Lt. Brad Penas, investigations commander.

“It just helps us determine what our next step is or what direction we want to proceed in,” he said.

The Cass County Sheriff’s Office uses the North Dakota Bureau of Criminal Investigation when it needs a polygraph test, which is normally only two or three times a year, Capt. Mitch Burris said. Depending on the severity of the case, the sheriff’s office may try to use the test when it has circumstantial evidence that points to a certain suspect, he said.

“We don’t just use it on defendants,” he said. “We may ask a victim to do a polygraph if we don’t think the victim is being truthful and we can’t find evidence to sustain what they’re telling us.”

Rust said about 70 percent of his work deals with convicted sex offenders required to take polygraph tests as a condition of treatment and/or probation.

Job interviews

Fargo is the only F-M law enforcement agency that requires applicants to take a lie detector test as part of the pre-employment screening process.

The questions typically pertain to drug use and past behavior, and police also use the test to gauge whether applicants were honest on their written application, Vettel said.

West Fargo police may require an applicant to take a polygraph test “if we feel there’s something there, but as a regular practice, no,” Sall said. Cass County doesn’t use the test in the hiring process, Burris said.

The federal Employee Polygraph Protection Act of 1988 bars most private employers from using lie detector tests to screen job applicants, but it doesn’t apply to public employers such as police agencies or other governmental institutions, according to the APA.

Minnesota law goes a step further than the federal law, prohibiting employers – including police agencies – from directly or indirectly soliciting or requiring a polygraph, voice stress analysis or “any test purporting to test the honesty of any employee or prospective employee.”

Results not admissible

Courts have repeatedly rejected polygraph test results as evidence in criminal cases because of their questionable reliability and accuracy.

As far back as 1950, the North Dakota Supreme Court held that polygraph test results are not admissible in a criminal trial. However, where the prosecution and defense have agreed that the test results should be admissible for the purposes of a motion for a new trial, the Supreme Court has held that the court must consider the results in determining the merits of the motion.

The court also has ruled it’s improper to admit evidence that speaks to whether the accused was willing or unwilling to take a lie detector test.

The U.S. Supreme Court weighed in on the issue in 1998 when it upheld Military Rule of Evidence 707, which made polygraph evidence inadmissible in court-martial proceedings. Justices opined that the rule didn’t violate the accused’s constitutional right to present a defense.

“… There is simply no consensus that polygraph evidence is reliable,” Justice Clarence Thomas wrote in the 8-1 opinion. “To this day, the scientific community remains extremely polarized about the reliability of polygraph techniques.”

Rust said he also provides polygraph services for defense attorneys. While those results also aren’t admissible as evidence in criminal court, they can still affect the outcome of a case.

For example, in the Cass County case of a Devils Lake man who was charged with luring a minor by computer, his attorney said at his January 2012 sentencing hearing that a lie detector test showed the defendant had no sexual contact with anyone under the age of 17 in the last five years and hadn’t met face-to-face with anyone he had met online younger than 17. Prosecutor Ryan Younggren didn’t dispute the polygraph results, saying they were “an important piece” in the plea agreement offered.

Cass County State’s Attorney Birch Burdick said he’s never seen the prosecution and defense agree to submit polygraph results as evidence, but he said it’s still information the state must consider.

“We weigh what we’ve gotten and what the value of that is and then make decisions based on that,” he said.

Polygraph results may be admitted as evidence in civil cases, but Rust said he’s only seen that happen once in his career, in an insurance case with a lot of money at stake.

Attempts to cheat ‘obvious’

The accuracy and reliability of polygraph tests continues to be a source of debate.

A report released in 2003 by the National Academy of Sciences concluded that a specific-incident polygraph test of a person who isn’t trained in countermeasures, or ways to cheat the exam, “can discriminate lying from truth telling at rates well above chance, though well below perfection.”

Rust said attempts to beat the polygraph test are usually “pretty obvious” to an experienced examiner. With the Internet, people can read online how to beat the test, “but if you really wanted to be good at it you’d have to sit down with a professional licensed examiner and understand the complete technique and then practice,” he said.

“What they do is quite obvious, and either you call them on it and tell them to stop doing that, or if it gets too bad, you just stop the exam and state the person is not being cooperative,” he said.

Last month, a federal judge sentenced an Indiana Little League coach to eight months in prison for teaching government job applicants how to beat lie detector tests, McClatchy News Service reported. Prosecutors described 34-year-old Chad Dixon as a “master of deceit” who taught as many as 100 people – including child molesters, intelligence employees and law enforcement applicants – how to beat the tests.

The judge, while acknowledging “the gray areas” between the constitutional right to discuss the techniques and the crime of teaching someone to lie during a government polygraph, said the prison sentence was “absolutely necessary to deter others,” McClatchy reported.


Readers can reach Forum reporter Mike Nowatzki at (701) 241-5528