DIRECT EXAMINATION OF MICHAEL SIGMAN BY CM
He is a faculty member at UCF. He has a PhD in chemistry. Joint appointment for the National Center for Forensic Science. BS in 1982 from SW Missouri State University. PhD in 1986 from FSU. He was an NIH post doctoral fellow at the University of Illinois and the University of Chicago.
He worked for 1 year as a research scientist for Dow Chemical. Staff scientist at Oakridge from 1990 to 2002 and then went to UCF.
He has known Dr. Vass since 1990.
Peer reviewed articles - he has 74 publications and book chapters. He's lectured 140 times.
Witness tendered as expert in Chemistry with no objection by JA
On 7/21/08 he received a call from Eric Walton from UCF police officer asking him to speak to Eric Striker about air samples from the car.
Striker told him he had talked to Dr. Vass and they wanted air samples taken from the trunk. Dr. Vass gave his name.
He then called Dr. Vass to ask what type of samples he wanted and what methodology to use. He knows Dr. Vass uses sorbent traps and said he didn't have any Discussed the use of a Tevlar bag and Dr. Vass said that would be acceptable.
He and his associate pulled a liter of air from the air and then 300 ml and put them in a second one. They did not have a pump, so they used a syringe. Trunk was closed when he arrive - opened it up just enough to extract the sample. He left the samples with OCSO - the larger bag was to go to Dr. Vass and the smaller bag went to UCF National Center for Forensic Science.
The first test they ran - they extracted 250 mcl from the bag and injected it into a GCMS. He then explained how the machine works. It is a widely used and well characterized method for doing chemical analysis.
They analyzed the sample and the results showed that there were trace amounts of volatile organic components, but the signal was not strong and the sample was not concentrated enough to be usable. The components were comparable to gas or other petroleum products.
In the first sample, the sample was too weak. They then took a second sample of 330 mcl using a solid phase micro-extraction fiber. This sample had a better signal. They determined if they wanted a better sample, to use the solid phase technique and the results were again consistent with gasoline.
He did not do any quantitative analysis.
Second sample identified several components of gasoline.
On 7/22/08 they returned with a solid phase micro extraction fiber and carbon strip for 40 minutes. They then placed them on ice and returned to the NCFS and analyzed them. The next day they went back to OCSO and left the solid phase and active charcoal filters for 7 hours. These samples had a stronger response showing a primary pattern of gasoline and that there was present in the sample chloroform ( solvent and also formed from the reaction of bleach with organic components in the environment), dimethyl disulfide (present in onions and cabbage and decomp).. and tetrochlorol ethyline (used in dry cleaning or degreaser). A quantitative analysis was not done, but could have been done.
He has not done direct studies on decomp. It is reported by Dr. Vass and Dr. Steferopolis that there are a whole host of compounds released in decomp.
It is his opinion, based on his samples and analysis, the three compounds were present, but gave very low readings, based solely on his data and test he could not conclude that there had been human remains in the trunk.
He understands that there was garbage found in the trunk of the car.
He took a total of 6 air samples - 2 tevlar bags, 40 min solid extraction fiber, 40 min carbon strip, 4 solid base micro extraction fibers.
The solid phase micro extraction fibers (40 min) and two 7 hour exposures contained the three components. They were not found in the tevlar bag.
No further questions.
15 minute recess. (10:09)