ORANGE PARK, Fla. (CBS/AP) Garbage trucks were the key to finding seven-year-old Somer Thompson's body and garbage trucks may be the key to finding her killer.
Officials say investigators tailed nine garbage trucks from Thompson's Florida neighborhood to a Georgia landfill and then picked through the trash as each rig spilled its load.
They sorted through more than 225 tons of garbage before the little girl's body was found.
At a news conference, Clay County Sheriff Rick Beseler said the quick discovery of Somer's body, two days after she disappeared, may have saved precious evidence that could lead to her killer.
"Had we not done this tactic," Beseler said. "I believe that body would have been buried beneath hundreds of tons of debris, probably would have gone undiscovered forever."
Searching landfills is common when children disappear, but it is unusual to try to zero in on them more efficiently by tracking a neighborhood's garbage trucks, said Ernie Allen, president of the National Center for Missing and Exploited Children.
Somer vanished on her one-mile walk home from school Monday in a heavily populated residential area, about a mile from a stretch of fast-food restaurants and other businesses, in the Jacksonville suburb of Orange Park.
Searchers combed the area before investigators, following garbage trucks that collected trash Tuesday, spotted her lifeless legs in a landfill about 50 miles away.
An autopsy to establish the cause of death is done, but authorities Thursday would not disclose their findings. Beseler would not say if Somer had been sexually assaulted or answer other questions about the condition of the body.
So far the police have questioned more than 155 registered sex offenders in the area. State online records show 88 sex offenders live in Orange Park, a suburb of about 9,000 people just south of Jacksonville Naval Air Station.
Now as the search for a missing girl turns into the search for her killer, the garbage trucks may again play a pivotal role.
Investigators will presumably try to pinpoint the trash bin or garbage can where she was dumped, based on the trash around her and the truck's pickup route. That could hopefully help them piece together a better timeline and offer a firmer direction for the investigation.
No arrests have been made.
MORE ON CRIMESIDER
October 22, 2009 - Somer Thompson Body Likely Found, Says Florida Sheriff
October 21, 2009 - Search for Missing 7-Year-Old Somer Thompson Leads to Body in Landfill
October 20, 2009 - Somer Thompson Vanished After School, Seven-Year-Old Girl Missing in Orange Park, Fla.