Several years ago, a story went around about an ingenious small town cop who hooked a young thief up to a copy machine the kid thought was a lie detector. When the suspect gave an answer the interrogator didn't like, he hit the print button causing a sheet of paper to come out of the copier that read, "Not True." The suspect, convinced he had been caught by a sophisticated lie detection instrument, confessed.
The copy machine-as-polygraph story illustrates an important point about scientific lie detection and how the polygraph technique can be used by examiners to coax confessions out of guilty suspects. The debate over polygraph accuracy, in this context, is not relevant. What does matter is this: most criminal suspects who happen to be guilty believe that the polygraph works. In the right hands it can be an effective interrogation tool. Years ago, the Georgia Bureau of Investigation made public a video-tape of a murder suspect's polygraph examination and follow-up interrogation. The transcript of this session reveals how a professional polygraph examiner/interrogator can use the instrument to acquire a confession.
The Jorelys Rivera Murder Case
On Friday, December 2, 2010, 7-year-old Jorelys Rivera, a resident of the River Ridge Apartment complex in Canton, Georgia outside of Atlanta, went missing. Three days later, police officers found her body in a dumpster not far from where she had been abducted. Ryan Brunn, a 20-year-old newly hired maintenance man had lured the girl into a vacant apartment where he had raped and murdered her.
On the day following the discovery of the murdered girl's body, Keith Sitton, a special agent with the Georgia Bureau of Investigation, gave the suspect a polygraph test. What follows is the word-for-word account of that session:
SITTON: Regarding that girl, do you intend to answer the [polygraph] questions truthfully?
SITTON: Did you participate in any way in causing the death of that girl?
SITTON: Do you know for sure who caused the death of that girl?
In discussing the results of the polygraph test with Brunn after the examination, Sitton said this to the suspect: "I can see you're not doing good on this test. Those [last two] questions are really bothering me."
"I promise you. I'll take the test again," Brunn replied. His voice was weak and he was obviously nervous.
"There's something on this that you're not telling us. Something that you're keeping to yourself. What is it you're holding back? Because we're going to solve this thing. It's just written all over you. Something's bothering you."
"I'm not bothered at all."
"You haven't told the complete truth about everything."
"I have," Brunn replied.
The GBI agent asked Brunn about having been accused of sexually fondling a young girl in Virginia: "You know what I'm talking about," he said.
"Remember, I said you had to be 100 percent truthful. I asked you [on the polygraph] if anyone made accusations. So what you have done is told me a lie."
"They put things in that child's head. I'm a good person. I didn't do nothing to that little Spanish girl, and I didn't do nothing to the other girl [the one in Virginia].
The next day, Sutton questioned Brunn again. He informed the suspect that according to the polygraph he had lied. To this, Brunn said, "I should have told the truth straight up. But I didn't. I was scared." At this point Brunn made a full confession. He said he had raped the girl, cut her throat, wrapped her in a garbage bag, and dumped her body in the trash compactor.
On January 17, 2011, Ryan Brunn pleaded guilty to murdering Jorelys Rivera. The judge sentenced him to life without parole. A year later, while serving his time at the Georgia State Prison, Brunn used his sweatshirt to hang himself.