A group searching for missing Washington County boy Jaliek Rainwalker says his adoptive father, Stephen Kerr, is not telling the whole truth. The 12-year-old disappeared last November from his Greenwich home. Shortly after that, Kerr, a man police call a person of interest in the case, gave a 28 minute interview to NEWS10's Anya Tucker.

The group, Texas EquuSearch, brought in two leading voice analysis experts to determine the truthfulness and/or evasiveness of the statements made by Kerr and his wife, Jocelyn McDonald, in that interview.

Now they want police to name Kerr, the last person to see Jaliek, a suspect in the case. NEWS10's Anya Tucker Reports.

"I have dealt with family members, and this is not the way family members react to someone missing. Not at all," said voice analysis expert and private investigator T.J. Ward.

Ward and his partner, Tom Winscher, have worked on high profile cases like the search for Natalee Halloway. In the case of Jaliek, they are hoping that technology called "Layered Voice Analysis" will help police here find out what happened to the boy. "Layered Voice Analysis" is basically a high-tech version of a lie detector test, which measures changes in voice frequency to detect truthfulness.

"When you are deceptive there are changes in frequencies in your voice, no matter who the person is," Tom Winscher told NEWS10.

Each word Kerr spoke in the interview was entered into a special computer program; the same kind of program that is used by Israeli's to ferret out terrorists. Ordinary stresses in the voice are disregarded, but the experts say any change in frequency will show if someone is lying or telling the truth.

"So we sometimes can find things that people subconsciously have hanging out there, and that is what we are looking for," Winscher said.

When studying the interview, Winscher says that Kerr's voice shows he was mostly truthful with NEWS10 when it came to cooperating with police early in the investigation.

Most disturbing to Ward though, is Kerr's behavior and his apparent quickness to anger. A statement by Anya Tucker, "I know you are very passionate about Martin Luther King," prompted a heated response in which he said, "No, I'm very passionate about my son. And you know what? If you can't rely on the people you call your heroes when times are tough - then who do you rely on?"

This came just minutes after a strangely playful moment when we readjusted the microphone NEWS10 affixed to him. With all of this on the same day we were talking about Kerr's missing son.

"It's sort of like he thinks it's funny and he doesn't care," Ward said, "and he is just not reacting like someone who has a loved one missing,"

Ward and Winscher have now recommended to police that Kerr become a suspect in the case. But there is a hitch to all of this. Layered Voice Analysis, just like lie detector tests, are not admissible in court. This is why it's unlikely it will be used against Kerr anytime soon.