(CBS/WKMG/AP) ORLANDO, Fla. - Dr. Arpad Vass, one of the state's key witnesses in the Casey Anthony murder trial, testified Monday that the odor of human decomposition in an air sample taken from Anthony's car was "extremely, overwhelmingly strong."
Vass, a researcher at the Oak Ridge National Laboratory, also known as the "body farm" for its study of human decomposition, ,pioneered a novel technique for detecting human decomposition from air samples, reports CBS affiliate WKMG.
Vass testified that the odor of human decomposition is different than the smell of animal decomposition.
"I jumped back a foot or two," Vass said of the odor he detected when opening a can containing an air sample from Anthony's Pontiac, reports the station. "It was shocking that strong of an odor could be in that little can."
Vass presented charts showing high levels of certain compounds in samples taken from Anthony's car. One of the compounds present, chloroform, Vass said was found in "shockingly high" amounts on a sample taken from a stained portion of carpet in Anthony's trunk, the station reports.
Chloroform is a chemical associated with decomposition but also can be used to render a person unconscious.
Lead defense attorney Jose Baez made several objections to Vass' testimony, attacking both his credentials and methodology used in doing his research. Baez also accused Vass of having a financial interest in the research he was presenting.
Baez briefly was permitted to question Vass' methodology outside the presence of the jury, but was stopped after Judge Belvin Perry said his questions were outside the scope of his original objection.
Perry previously issued a pretrial order denying a defense request to exclude the air tests from the carpet sample taken from Anthony's car. Until now, the tests had never been admitted in a trial in the United States.
Prosecutors are trying to prove that Anthony suffocated her 2-year-old daughter, Caylee, with duct tape in the summer of 2008. The defense said the toddler drowned in her grandparents' swimming pool, reports WKMG.
Anthony has pleaded not guilty. If convicted, the 25-year-old Anthony could be sentenced to death.