Search for Somer Thompson: Experts say landfill forensics search isn't easy
It's hard to preserve and gather clues even under the best conditions
[snipped...]For homicide investigators, it's one of the most difficult searches to make: sifting through mounds of garbage in hopes of finding leads.
On Wednesday afternoon, a slow and careful search of the Chesser Island Road Landfill in Georgia ended with a grisly discovery - the body of a young girl, presumed to be a 7-year-old Orange Park girl missing since Monday.
Georgia investigators began searching the landfill Tuesday for clues in the disappearance of Somer Thompson. The landfill is where garbage trucks from Orange Park take their trash.
Experts say searching a landfill for criminal evidence can be difficult because there's so much risk of contamination.
Ross Gardner, a national forensics expert based in Oklahoma, said it's usually easy to know where to start looking, because most landfills are strictly organized into cells by location and date.
If it's not well-organized, then "it's kind of poke and hope," said Gardner, a former Army crime-scene investigator and chief of police in Lake City, Ga.
But even at an organized site, landfill searches are a huge challenge. Almost as soon as debris is spread atop the dump, it's compacted by steel-wheeled rollers. By the end of the first day, it will usually be covered with soil to control odors.
"Even in a fresh situation like they were dealing with [in the Somer case], unless you're so lucky that the body just pops out on top, you're going to have to do some excavation," said Paul Laska, a forensic consultant in Palm City. As a crime-scene investigator, he spent a month in 1993 excavating a Martin County landfill looking for a little girl's body.
That can mean bringing in cadaver dogs trained to sniff for human remains to help narrow the search.
Once crews find debris from the right day and hauler, the search can become more like an archaeological excavation, he said, with material sifted delicately, despite the damage already done by daily landfill operations.
It can be difficult to recognize meaningful evidence in a small mountain of twisted refuse and decay.
"You've got broken glass, broken metal, a lot of just nasty stuff in there," Laska said. "You're going to find bones, because that's a garbage dump."
If a body is discovered, it can be difficult to preserve DNA evidence - even if investigators move slowly and carefully. Most of the evidence can be contaminated before search crews even arrive.
Though evidence of sexual abuse inside the body may be preserved, Gardner said anything on the exterior of the body might not hold up as evidence because so much trash gets mixed together. Debris surrounding the body could be connected to the case, such as a glove or a piece of clothing, but that can be very hard to prove.
(more at link)
