After a team of more than 100 organized volunteers spent Friday in an expanded search for a 5-year-old girl missing for more than three days, an upbeat spokesman called the day "very productive."

"We did discover some items of interest. I can't go into detail as to what those items are, "Putnam County Sheriff's Office Capt. Rose said in an afternoon news briefing. "We are very hopeful that she is alive ... and we are looking forward to a very positive outcome."

Haleigh Cummings was last seen when she was put to bed at 10 p.m. Monday in her father's home just north of Satsuma.

She was reported missing by her father and his girlfriend about 3 a.m. By first light, a massive search was under way and a statewide Amber Alert was issued.

On Wednesday, with no sign of Haleigh and a belief that a 5-year-old would not go out in the dark alone, investigators said they considered her disappearance an abduction.

Late Friday, the assessment was the same, but the tone was more optimistic.

"We continue to believe this could be an abduction," Rose said. "Whether she was abducted from her own or Haleigh left on her own and somebody picked her up, of course, that person has no rights to Haleigh and that is considered an abduction."

Putnam County Sheriff Jeff Hardy said his investigators have pursued more than 350 leads and the planned to reinterview family members and others who had contact with Haleigh.

"At this time, the world is a suspect," Hardy said. "We really haven't excluded anybody."

Several dozen sex offenders and predators living within 5 miles of the Cummings home have all been interviewed and their homes checked, Hardy said.

Dominick Pape, special agent in charge of the Jacksonville office of the Florida Department of Law Enforcement, said forensic evidence collected during the investigation such as DNA and fingerprints would be a priority.

About 20 agents are working around the clock at a command center parked near the doublewide mobile home where the girl went missing.

Hardy said the experienced volunteer searchers with Texas Equusearch will allow them to cover some difficult terrain and broaden the search area.

"We've observed it from the air, obviously, but we want to get some people on the ground in there," Hardy said. "The areas that the Equusearch people are going to be looking at and it's extremely think and very dense. It's going to be a very tough search today."

Texas Equusearch use horses, all-terrain vehicles and different types of sonar technology in searches for missing people. They have worked on more than 1,000 cases, including searching for missing Orlando toddler Caylee Anthony last fall and Natalee Holloway in Aruba.

Last week, a 2-year-old child was located with the group's help.

"I've been in the same shoes as this family when my own daughter disappeared. Unfortunately, 17 months later, her body was found. I made a promise to God that I'd never leave another family alone," said Tim Miller, founder of Texas Equusearch.

"We just didn't think we'd be back in Florida this close to where Caylee disappeared in this short period of time. It brings back some painful memories," Miller said.

The Putnam County Sheriff's Office asked for the group's help, hoping "a fresh set of eyes" will help lead them to Haleigh.

After Equuasearch's first day, authorities said they they will mount another search on Saturday.