ORANGE PARK, Fla. -- Detectives searching for a 7-year-old's killer have interviewed more than 100 sex offenders living nearby, sifted through tons of garbage and combed the well-kept neighborhood where Somer Thompson disappeared.

Missing child posters featuring the slain girl's face, framed by her thick brown bangs, still plaster nearly every utility pole along the mile-long route from Grove Park Elementary School to her home.

Friday evening, Diena Thompson appeared at a candlelight vigil held for Somer, saying her daughter's body will be released to the family for the viewing and memorial next week, but investigators told her she will not be able to see the body.

Instead, Thompson said a lock of Somer's hair will be given to her.

"I'm not going to be able to see her, and I wanted to to tell somebody that," Thompson told friends and supporters. "Maybe it will just make somebody want to say something. If you've seen anything, please, just tell."

Somer was last seen alive walking along the sidewalk in front of a vacant, burned out house on Gano Avenue. Friday, as authorities spent a second day looking for evidence in that house, they said they continue searching for anyone who saw what happened to the 7-year-old after that.

So far, no witnesses have come forward to say they saw Somer attacked or abducted, sheriff's spokeswoman Mary Justino said.

Justino said Friday afternoon that about 900 leads have now come into the Clay County Sheriff's Office tip line, and about 200 of them remain under investigation.

At least 50 detectives will working through the weekend on the criminal investigation -- some still looking for evidence in the 225 tons of garbage that arrived at the Charlton County, Ga., landfill on Tuesday, and the rest working leads in Orange Park.

"We certainly remain encouraged at the progress we are making in this case, but we do want to still encourage people who think that they may have information that could help us to call in to that tipline," Justino said.

The child's teary but resolute mother talked with Channel 4's Casey Black Friday morning, warning her daughter's killer: "We'll get you." She pleaded for anyone with information to "please, please tell" police.

Asked how she's remained strong through this ordeal, Thompson credits the support she has received from those close to her and from total strangers.

"I wish I wouldn't have to be here and experience this, but I don't think, if it wasn't for my friends and family and these people I would be able to get through this," Thompson said.

The day after Somer's body was identified, authorities said they had ruled out all 161 registered sex offenders who lived within a 5-mile radius of the girl's home. Despite doggedly pursuing hundreds of leads, police have not made an arrest.

Somer vanished while walking home from her elementary school on Monday afternoon. The vacant house is on her route through a heavily populated, well-manicured neighborhood, and witnesses last saw the girl alive in front of it. She had gotten upset as she walked home with other children Monday and ran ahead of the group. Somer never made it home.

Neighbors said they were used to watching out for each other's children as they walked to and from school.

Everybody knows everybody here. If there was a stranger on the street, we'd be looking at watching where they were going, seeing what they were doing here," said Monica Loeb, a family friend of the Thompsons.

Somer's mother had a friend greet her children as they came home from school Monday because she was working, according to a police report.

When Somer didn't arrive with the other children around 4 p.m., the friend sent Diena Thompson a text message. She raced home, and flagged down a passing police officer while she, her other children and her boyfriend scoured the neighborhood.

An autopsy was completed by the Georgia Bureau of Investigation and investigators say they know how Somer died, but authorities won't disclose their findings or any details about the body.

Mourning neighbors and others have gathered every night outside the home. On Friday, the mother joined them to sing Somer's favorite song, "You Are My Sunshine."

Thompson spent part of Friday making funeral arrangements, and a law enforcement officer was seen carrying a child's white dress from the family's home. A viewing will be held Monday night and a funeral will follow on Tuesday.