A body in the boot of alleged killer mum Casey Anthony’s car is the only plausible explanation for the smell detected there, her capital murder trial in Florida has heard.
"The odour was extremely overwhelming ... I recognized it as human decomposition," claimed expert witness Arpad Vass as the trial of Anthony (25) moved into its third week.
Vass, a pioneer in the biochemistry of human decomposition at the Oak Ridge National Laboratory in Tennessee said the test results confirmed what his nose had already told him. But defense lawyer Jose Baez has dismissed his findings as "junk science".
Casey Anthony is standing trial for a first-degree murder charge stemming from the June 16, 2008, death of her 2-year-old daughter Caylee. If convicted she faces the death penalty.
Prosecutors are trying to prove that Anthony suffocated her daughter with duct tape and contend that traces of decomposition were found in her car.
Anthony has pleaded not guilty. Her defense attorney says the toddler drowned in her grandparents' swimming pool
Vass testified that he has worked for 20 years in the Oak Ridge lab's outdoor body farm, where human remains are studied in various stages of decomposition.
He said he has worked with 50 bodies from the time of death until they were skeletonised, plus hundreds of other bodies in various stages of decay.
In the air analysis of the car trunk sample, Vass said he and other scientists detected 51 compounds including an unusual quantity of chloroform. Chloroform is released by decaying bodies, Vass testified.
"We were shocked. We had never seen chloroform at that level," Vass testified.
Legal experts say the air analysis could be used as grounds for an appeal if Casey is convicted..
Defense lawyer Jose Baez objected repeatedly to Vass' testimony yesterday. He argued Vass was testifying out of his field of expertise or about lab work performed by another scientist at Oak Ridge.
At one point, Baez questioned Vass out of the jury's presence so the trial judge could hear what questions the defence attorney wanted to ask.
During that exchange, Vass told Baez, "I don't think you quite understand what's happening here."
In their opening statement, prosecutors told jurors someone had researched chloroform, once a popular anesthetic, on the Anthony family computer in the months before Caylee's death.
Vass testified the lab also conducted laser tests on a sample of the carpet from Casey's car trunk to look for inorganic elements such as calcium, sodium, magnesium, iron and carbon. Vass said calcium was found in the greatest quantity.
"They showed the inorganic elements associated with human decomposition were significantly elevated," Vass said.
Further chemical tests of the carpet were performed to look for compounds that had not been converted to a gas but were stuck in the fibers. Vass said the tests uncovered butyric acid.
"It is the first (fatty acid) compound liberated during human decomposition," Vass said.
Vass said all the results were compared to tests of samples of carpet from the trunks of two cars pulled from a junkyard in Knoxville which showed no significant levels of any of the compounds or elements.
Judge Belvin Perry previously issued a pretrial order denying a defense request to exclude the air tests.
Until now, the tests had never been admitted in a trial in the United States.
Setting the stage for Vass' testimony, Orange County Sheriff's Office crime scene supervisor Michael Vincent testified on Saturday that he helped obtain several air samples from the car trunk and a forensics bay where the sheriff's office stored the car.
Vincent said air samples also were taken from a bag of trash that had been in the car trunk.
The samples were sent to Vass. The Oak Ridge lab deems his work "groundbreaking," but defense lawyer Jose Baez has dismissed it as "junk science."
The trial in Orlando, Florida continues.