Science in the Air in Caylee Anthony Case

Lawyers for Casey Anthony, the Florida mother accused of murdering her two-year-old daughter, Caylee in 2008, say the smell of death coming from her car days after the disappearance of her daughter was the result of a garbage bag that had been left in the trunk. A scientist used an untested forensics technique to tell a different story: that smell was the lingering odor of human decomposition.

Prosecutors brought in Oak Ridge National Laboratory senior researcher Arpad Vass, an expert in odor detection, to test air from Anthony’s car for signs of human composition. Vass and a colleague were given a sealed can containing a scrap of upholstery from the car, and using a syringe they extracted some of the air inside.

The scientists then ran the air through a gas chromatography-mass spectrometry device to analyze it for substances, and cross-referenced those results against a database of more than 400 chemical traces of decomposition that Vass has compiled. According to Vass, the air contained an “overwhelmingly strong” scent of decomposition.

Vass said he and his team identified 51 chemical components from the carpet of the car trunk. Of those, 41 were consistent with human decomposition, including butyric acid, the first compound found in human decomposition, in the carpet.

Although this technique has never been used in court before, it could become a regular tool in both the investigation and prosecution of crimes.