Direct examination of Dr. Arpad Vass by JA continued.
He indicated on Exhibit 123 the chloroform peak. The numbers showed rough approximations of amount of material present. Top # was 16 million counts. This from ICA's car. He then showed another group of peaks which he identified as components of gasoline. There are overlapping compounds of gas and the odor of decomp. Gas cans were in car. Looking at second chart - chromatogram of a standard vehicle, from a junkyard in Knoxville - a car of similar year, make and model. He indicated where the chloroform was on this one.
(Dr. Vass is so cute and bubbly - hard to believe he works with decomp all day).
The chloroform in the standard car was no more than 5,000 at most, as compared to 16 million in the trunk.
In addition to the peak height, you have to look at the area under the peak. Software is used to obtain that area. For ICA's car, the area under was about 400 million. The area under the control sample from two different cars was 10,000. Chloroform is in environmental samples, but it is typically.... (objection by JB - overruled). Chloroform in environmental samples are typically trace amounts.
Carpet was also tested for presence of inorganic compounds - laser inducted breakdown spectography (LIBS) - a nondestructive technique so that the defense could veryify the results.
Objection by JB - overruled.
LIBS a laser based technique - a YAG laser creates green light. (Asked to slow down - he says he gets excited when he knows something - so cute).
Laser is directed onto the carpet. Elements are either in a ground or excited state. Laser sets up an excited state of the electrons. When the laser is turned off, the electrons fall down to a ground state. They then emit the energy they acquired.
Objection by JB - overruled.
The energy produced during excitation of electrons is released as a photon of light and picked up on a spectrometer. Every element produces a light signature. LIBS can be used to identify the elements present in a particular sample.
This technique was used on carpet sample. He was not present when this was done, but he utilized the results in his opinion.
Regarding results of the LIBS exam of the carpet - they were looking at elevated inorganic components consistent with decomp.
He was shown a graph of the results. JB objects to Exhibit - wants to voir dire witness as to methodology.