The full-scale search for a missing 9-year-old girl ended its final day as law enforcement officers turned to child abduction experts for help.

Investigators and hundreds of volunteer searchers have uncovered little evidence during five days of scouring the rural area where Jessica Lunsford disappeared, and the full-scale search was suspended Monday afternoon.

"To continue this, we would be spinning our wheels," said Citrus County Sheriff Jeff Dawsy (search).

Instead, law enforcement officers were turning to 20 experts from the National Center for Missing and Exploited Children (search) to help crack the case. They planned to focus on a three-quarter mile radius area around Jessica's home.

Jessica's father described the change as a second phase of the investigation. After making a plea for her safe return while choking back tears, he expressed confidence that his daughter would come home.

"Just drop her off. I'll come get her," Mark Lunsford answered when asked what he would say to whoever had Jessica. "I know whoever has got Jessie, they have to have a heart."

He also expressed gratitude for the outpouring of support. "It's been overwhelming, the people that have shown up," he said. "It makes me feel real good to know everyone's trying to help me out."

Lunsford said he remains convinced that his daughter did not leave home voluntarily even though authorities have uncovered no evidence she was abducted. He said it's unlikely Jessica was lured away.

"She just didn't go with strangers," Lunsford said. He said authorities also are looking for a stuffed purple dolphin missing from his daughter's room.

The sheriff said nothing suspicious was found on the family's computer and that Lunsford and his father, Archie Lunsford, had both passed FBI (search) tests that measure changes in voice stress levels as a way of verifying whether a person is telling the truth.

Mark Lunsford also passed an FBI polygraph test. "None of his answers to questions set any alarms off," Dawsy said.

Jessie hasn't been seen since her grandmother tucked her into bed Wednesday night; the girl's father discovered she was missing early Thursday.

Some of the 160 volunteer searchers who showed up Monday were frustrated that they found no clues.

"There is disappointment, I guess," said William LaVerle Coats, pastor of Faith Baptist Church, where Jessica Lunsford attended services last Wednesday shortly before disappearing. "We are expecting a miracle."