It’s certainly no lie that polygraph tests results are persona non grata in courtrooms in South Carolina and most other states.
Judges have long been skeptical of the examinations. Larry Hyman Jr., a South Carolina at-large judge, wrote in 2010 that their results aren’t admissible as a matter of public policy and judicial efficiency.
Not only are they unreliable, he wrote when he denied a motion to allow lie detector test results in a Horry County murder trial, they have the potential to open the floodgates for prisoner litigation. Law enforcement has long used polygraph examinations for criminal investigations in South Carolina, and Hyman reasoned that allowing their admissibility would lead to every defendant who has ever taken a lie detector test to either try to get the results admitted, or attempt to have another polygraph examination administered.
“Given the potentially high monetary cost, the potential for massive amounts of litigation on old cases, and the low reliability and utility of the polygraph examination, this court finds that polygraph examinations are inadmissible in court,” he wrote.
But polygraph exams are fair game for law enforcement, prosecutors, and the defense in investigations and negotiations, and some attorneys keep them in their war chests as weapons to leverage their more difficult cases.
“In some cases–not in every case–if I have a situation where a client profess their innocence, we may give them the opportunity to take a polygraph test,” said Dan Blau, a criminal defense and appellate attorney in Raleigh. Blau calls them “an arrow in my quiver,” and a successful polygraph test can help bolster a defense case in several ways, he said.
If a person’s under investigation but hasn’t been charged, a defense attorney can use a successful polygraph as leverage to keep law enforcement or a district attorney from filing charges, or at least give them pause and possibly file lesser charges.
Blau stresses, though, that it’s entirely up to law enforcement or prosecutors to make those calls. Some are open to polygraph results, while others want nothing to do with the tests, which measure factors such as blood pressure and respiration.
“Don’t expect that the results of the polygraph are going to be the determining factor in what happens in a case,” he said. “Different people have different opinions on the validity of a polygraph exam. I know a law enforcement officer who was a polygraph analyst, and she put hardly any stock in it at all. You never really know exactly how it will be received. However, if you have a client who wants to do everything to prove their innocence, it can be a very valuable tool.”
A client also has to have the money for the test, which can cost up to $1,000, so a person charged with a serious crime is much more likely to opt for one versus someone who is charged with shoplifting, Blau said.
Another way the results can help is if someone is charged with a crime such as sex abuse, an accusation that often tears families apart, pitting relatives against relatives. If a client passes a polygraph test in such cases, the results might sway some family members into accepting their claims of innocence.
Blau said that successful polygraph results “can be an opportunity for a client to demonstrate to his friends or family or other people that he did not do what he is accused of doing.”
Defense attorneys can also use polygraph tests to help craft a defense strategy for a client whom they don’t believe is telling the truth, said Andrew Goldstein, a polygraph examiner who conducts the exams for attorneys in South Carolina.
“Sometimes the attorney just wants to know if the client is telling the truth,” Goldstein said. “I go in there to see if they are being honest. What the attorney does with the information is their business. They are there to help the client and sometimes helping them is not putting them in front of a judge or a jury when they are better off taking a plea deal.”
After a conviction, the test can be useful pre-sentencing, Blau said. He took on a federal case where a man was convicted of drug trafficking. The man took a lie detector test that ostensibly showed he didn’t traffic as much drugs as he was accused of. Blau submitted the findings to the officer who prepared the man’s pre-sentencing report, and he got a lighter sentence
Rufus Edmisten, a partner with Edmisten & Webb Law in Raleigh, was North Carolina’s attorney general when the North Carolina Supreme Court ruled polygraph test results inadmissible in that state. He was also deputy counsel for the U.S. Senate’s Watergate Committee, whose chairman, the late U.S. Senator Sam Ervin, famously called lie detector tests “20th Century witchcraft.”
For his part, Edmisten knows of an attorney who kept a polygraph machine in his office, and SBI agents under his watch used the exams for investigative purposes.
“I can find times when they are useful,” Edmisten said. “I would say that the biggest use for them was that they do promote confessions. There are many times when people would be hooked up to the lie detector and they would confess. I have also seen times when a brazen liar can beat a test up one side and down the other.”
That being said, Edmisten said a polygraph test can be “a good tactic” for an attorney.
“If it is used as leverage and is considered with other evidence, that’s just fine,” he said.
Follow Bill Cresenzo on Twitter @bcresenzosclw