(CNN) - The presence of a decomposing human body is the only plausible explanation for the odor in Casey Anthony's trunk and the results found in forensic testing, a scientist testified Monday in her capital murder trial.
Testing was conducted on carpet samples from the trunk of the Pontiac Sunfire, along with a spare tire cover, scrapings from the wheel well, air samples and paper towels found in a trash bag that had been in the trunk, Arpad Vass, a senior research scientist at Tennessee's Oak Ridge National Laboratory, testified in the Orlando, Florida, courtroom.
Vass, who spent all day Monday on the stand, said he and his partners have, as part of their general research, identified some 30 compounds as significant in the human decomposition process. Seven of those were confirmed in Anthony's trunk, he said.
Of those, Vass testified under cross-examination by defense attorney Jose Baez, only five were considered because the other two were at trace levels. "We were very, very conservative," Vass said.
Prosecutor Jeff Ashton asked Vass if, given the test results and his own observations regarding the odor, he believed a dead body had been in the trunk.
"I can find no other plausible explanation, other than that, to explain all the results we found," Vass said.
Casey Anthony, 25, faces seven counts in the death of her 2-year-old daughter Caylee, including first-degree murder, aggravated child abuse and misleading investigators. If convicted, she could face the death penalty.
Caylee was last reported seen by her family on June 16, 2008, but no one alerted police until July 15, when the girl's grandmother, Casey Anthony's mother, tracked Anthony down and demanded answers.
Prosecutors allege Anthony used chloroform on her daughter and suffocated her by putting duct tape over the little girl's mouth and nose. They allege Anthony put her daughter's body in her car trunk before disposing of it. Caylee's skeletal remains were found in December 2008, less than a mile from the home of Anthony's parents.
Anthony has pleaded not guilty and denied having anything to do with her daughter's death. Baez has said that when all the facts are known, it will become clear his client is innocent.
The Orlando woman's attorneys argue Caylee drowned in the family pool on June 16, 2008. They say Anthony and her father panicked and covered up the death. George Anthony denied the claim during his testimony.FULL STORY
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