Meaning of Failed Polygraphs in Hailey Dunn Case

"They asked if I knew anything about the disappearance of Hailey," said Billie Dunn, the mother of the missing Colorado City teen, on her second appearance on "Nancy Grace."

There she was asked about the polygraph test that she and boyfriend, Shawn Adkins took.

"He took his, I went in, they told me he failed it, I lost it," said Hailey.

She went on to say, "They took me to the courthouse, I took the polygraph test, I failed it."

So what does this mean when both people closely connected to Hailey fail the test?

"If there is a failure or a deception indicated, generally speaking it would indicate the person quite possibly could have some knowledge or involvement in the disappearance of the person," explained Mike Gougler, a polygraph expert

Gougler is not directly involved with this search, and could not speak about the case specifically, but in his experience he says these type of tests can really aid in the investigation.

"When they start running polygraphs early on, they're trying to eliminate people so they can focus their efforts on the most important factor, and that's the safe recovery of the individual that has disappeared."

Gougler says everyone who takes a polygraph is typically told afterwards if they passed or failed, so that's not unusual, but it's unknown if Billie Dunn's claim to know the results of her boyfriend's test will have any impact on this investigation.