"All the world is a suspect," Detective John Merchant of the Putnam County Sheriff's Office told reporters. "We are going to treat everybody, every family member, every associate, like a suspect until we eliminate them."
As police launched a massive search effort that included divers and K-9 units, Crystal Sheffield, begged for her daughter's return.
"Whoever has her, I know you're watching," Crystal told "Good Morning America" in February. "She ain't done nothing wrong. Please bring her back."
Haleigh, whose parents do not live together, disappeared from Ronald Cummings' Satsuma, Fla., home on Tuesday, Feb. 10. He reported her missing in an desperate 911 call.
"I just got home from work and my 5-year-old daughter is gone," he told a dispatcher. "If I find whoever has my daughter before you all do, I'm killing them. I don't care if I spend the rest of my life in prison."
There are 44 registered sex offenders within a five-mile radius of the home.
Police were interested in one sexual predator wanted in Marion County, although he is not considered a person of interest in the girl's disappearance.
Ronald Cummings had left Haleigh and her 3-year-old brother in the care of his 17-year-old girlfriend, Misty Croslin.
"She was sleeping right next to me," Croslin told the Palatka Daily News. "I can't believe I didn't hear anything."
Ronald Cummings told police that when he returned from work early Tuesday morning, the back door was propped open and Haleigh was gone.
"Somebody came in my back door, broke into my home and stole my daughter," he said.
"I don't know why somebody would take her," the mother said. "I'm scared for her. She is probably scared and cold and hungry."
The Associated Press contributed to this report.