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3. The new science of odor analysis is controversial
One of the most disputed pieces of evidence is the result of a new odor-analysis technique developed by Arpad Vass, a forensics anthropologist at Oak Ridge National Laboratory in Tennessee. He claims that his research on cadavers at the University of Tennessee's "body farm" (an outdoor research lab where donated bodies are allowed to decay to study human decomposition) yielded a database of 400 chemical vapors he calls "decomposition odor analysis." Vass testified that the air in Anthony's trunk contained definitive signs of decomposition.
Vass has published articles in the peer-reviewed Journal of Forensic Studies, but Kobilinsky argues that his analysis should not have been admitted given Florida's Frye standard. "Its what the state calls 'state of the art.' It's what I call 'not ready for prime time,' " he says. "It's not junk science, but it never should be brought into a courtroom at this stage."
Prosecutors have also tried to show that the trunk contained unusual levels of chloroform, the chemical they allege Anthony used to kill her daughter. Tests conducted on the air in the trunk by the FBI laboratory and by Vass's odor-analysis technique long after Caylee's disappearance indicated high levels of chloroform. "Chloroform's quite a volatile liquid, and it wouldn't really stick around for that long," Ruth Smith, a professor of forensic chemistry at Michigan State University, says. "Meaning that if chloroform had been used, it was used at very, very high levels, which would not be common." The defense attacked Vass's odor-analysis technique as unreliable for proving decomposition of a body and blamed the stench on garbage found in the trunk.
4. Even evidence of flesh-eating insects isn't proof of a dead body
To bolster the idea that Anthony's car trunk once contained a decomposing body, forensics entomologist Neal Haskell testified about insects found in garbage in the trunk. Insects are common in murder cases where a body is found outside. "You'll have bugs, various insects, and their larvae will be in [the remains]," says Charles Hitchcock, director of autopsy services at Ohio State University. "In that case, you'll sample those at the crime scene."
But without a body in the trunk, Haskell's testimony focused on insects that commonly swarm decomposing bodies. Haskell explained that the chemical composition of a decomposing body changes, and the insects attracted to the corpse will also change, allowing him to create a possible timeline for how long a body (though he could not prove it was a human body) may have been in the trunk, in this case three to five days.
Defense lawyer Baez challenged the idea that the insects were attracted specifically to a decomposing body, asking whether leftover food could also attract the bugs. Haskell explained that the insects in question would be attracted to "decomposing organic material," which is consistent with the prosecution's theory that Caylee's body was in the trunk. But then again, as we've heard, "consistent with" is not absolute proof.
5. Human remains don't tell the whole story
When investigators found Caylee's remains in December 2008, six months after the girl was last seen, it wasn't a pretty sight. Her body had decomposed in a wooded area 20 ft. (6 m) off the road and less than a mile from her grandparents' home. Although investigators found 350 pieces of evidence at the crime scene, they could collect only a handful of bones.
Unlike most fictional cases, finding Caylee's remains yielded few definitive answers. The duct tape found on her skull contained no DNA. "Duct tape in general is great physical evidence in criminal cases," Kobilinsky says. "There is no way anybody can determine if the duct tape had been put on before, during or after death. There's no way you could do it scientifically or medically."
Jurors saw pictures from the crime scene and heard graphic details about plants and bugs that had infested Caylee's remains. "If you have skeletal remains, you're looking for every bone that you can find, and then try to reconstruct," Hitchcock of Ohio State University says.
Anthony's lawyers will likely emphasize that medical examiners were unable to pinpoint the cause of Caylee's death, but Hitchcock explains that can often be the case. In nearly 10% of medical autopsies, it is impossible to definitively determine the cause of death, a percentage that increases in criminal cases. "It is a giant puzzle," Hitchcock says. "It's attention to detail. Every coroner, every medial examiner, every forensic pathologist and dentist and anthropologist is really anal-retentive."
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