FLORIDA detectives searching for a seven-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.

Somer was last seen alive walking along the sidewalk in front of a vacant house, and authorities said on Friday that they're searching for anyone who saw what happened to the seven-year-old after that. Investigators sifted through evidence from that vacant house and the Georgia landfill where her body was found Wednesday.

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

"What we've been trying to figure out is who frequents that area, because obviously it's more than just the people who live there," she said.

The child's teary but resolute mother appeared on television interviews and warned her daughter's killer: "We'll get you." She pleaded for anyone with information to "please, please tell" police.