Investigators are now taking a closer look at the stepmother of Kyron Horman, the 7-year-old Oregon boy who vanished from his elementary school almost three weeks ago.
Police have distributed a questionnaire in the Portland, Ore. area asking local residents about Terri Horman and the truck she was driving when she took the boy to school the day he disappeared.
They've also asked Harmon to take two polygraph exams. The move is not unusual in a cases like Kyron's because the polygraph examiner can have a difficult time zoning in on the right questions.
"Certainly the concern is whether the child has been murdered, kidnapped, whatever," polygraph examiner Ken Simmons. "But they don't know, as far as I know, so they're shooting in the dark. And that makes the test more difficult than if you knew specifically what happened."
Although investigators haven't said whether Harmon is a suspect, the recent attention focused on her has her friends coming to her defense.
"She's the last person who saw Kyron, and so it makes sense that she's looked at," Jaymie Finster, a friend of Harmon, conceded. "But, you know, I guess we wonder how long that will take before they see she didn't do anything."
Polygraph experts said people shouldn't make too much of the fact Harmon has gone through the procedure twice.
"I'm certain they would be looking at her, but I don't think it would indicate she's the one and only or that they're confident it's her," Simmons said.
Detectives have insisted they're just trying to be thorough. So far, there's been been no arrest and no trace of the 7-year-old boy.
"We can't release specific information about the investigation because we can't compromise it," Multnomah County Sheriff's Spokeswoman Lt. Mary Lindstrand told CBS affiliate KOIN. "We will not compromise the investigation."