Forensic Expert Testifies About Decomposition, Chloroform Allegedly Found in Trunk

One of the prosecution’s key forensic experts testified on Monday morning about the analysis his laboratory conducted on carpet and air samples from the trunk of Casey Anthony’s car.

Dr. Arpad Vass of the Oak Ridge National Laboratory, sometimes referred to as “the body farm,” explained to the jury how human decomposition works on a cellular level and what chemicals are produced during the process. He stated that in his experience dealing with hundreds of dead bodies—and following the decomposition of approximately 50 of them from start to finish—the odor of human decomposition is unique and is even distinguishable from animal decomposition.

When he opened an air sample taken from Anthony’s trunk after her daughter Caylee was reported missing in July 2008, he testified that he “essentially jumped back a foot or two” because the smell was overwhelmingly strong. He said he recognized the odor as that of human decomposition.

Vass also spoke about the chemical compounds discovered while testing a sample from the trunk’s carpet. He showed the jury graphs indicating one particularly large peak in the level of chloroform. He said experts in the lab found the amount of chloroform to be “shockingly high,” so they conducted additional testing on it.

He identified chloroform as one of the chemical compounds that they have found to be produced during human decomposition. Prosecutors have also alleged that Casey Anthony researched how to make chloroform on the internet earlier in 2008.

Another test found butyric acid in the fibers of the trunk lining. Vass testified that would be the first chemical compound released during decomposition.

Defense attorney Jose Baez objected to Vass’ testimony, and Judge Belvin Perry heard arguments on that issue earlier this year, but Perry had ruled that the jury should be able to determine the credibility of the evidence themselves. Some of the forensic testing methods Vass used on air samples in this case have never before been admitted as evidence in a US court.

Outside the jury’s presence, Baez questioned Vass about data he was using from tests that others in his lab performed, but Perry stated that expert witnesses are allowed to rely on reports by others to form their opinions. Vass’ testimony is expected to continue Monday afternoon following the lunch break.