Opinion ID: 1210687
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Heading Rank: 9

Heading: Graph 1: Comparison of Ballard and Siuzdak EDTA Measurements [6] (Excluding Samples 1 and 8)

Text: The consistency in results for Dr. Siuzdak and Dr. Ballard strongly suggests that Dr. Siuzdak's results are valid. That is, if Dr. Siuzdak had EDTA contamination in his lab or if his instruments were miscalibrated, the contamination or miscalibration affected all of his measurements equally. If this is true, Dr. Siuzdak's resultsas measurements of relative rather than absolute amounts of EDTAare valid. For purposes of this comparison (and of the above graph), I excluded Samples 1 and 8. Sample 8 is a control not taken from the t-shirt. It is a piece of cloth onto which Dr. Maddox at Orchid Cellmark had placed a known amount of EDTA-preserved blood, with a known concentration of EDTA. Both Dr. Siuzdak and Dr. Ballard found greatly elevated levels of EDTA in Sample 8, though Dr. Siuzdak found a relatively higher EDTA level. That difference may be partially explained by Dr. Siuzdak's relatively higher amounts of EDTA for all of his samples. The remaining disparity may not be significant. Dr. Terry Lee, an expert hired by the State to evaluate the results of Dr. Siuzdak and Dr. Ballard, concluded that the disparity in results for Sample 8, considered by itself, was not significant. Respondent's Analysis of EDTA Test Results, Oct. 28, 2004, Docket No. 264, Ex. A at 2. That leaves Sample 1. Sample 1 is the new sample thought to contain Cooper's blood. It was chosen by Dr. Maddox and Mr. Myers to replace the old sample from Area 6G. Though Sample 1 supposedly contained Cooper's blood, we cannot be sure that it did, as I explained above. Dr. Siuzdak measured an extremely high level of EDTA for Sample 1. Dr. Ballard measured only a somewhat elevated level of EDTA for Sample 1. A possible, perhaps likely, reason for the disparity in their results is that Dr. Siuzdak's piece of Sample 1 contained a great deal of Cooper's blood, while Dr. Ballard's piece contained significantly less, perhaps none. Sample 1 was an unusually large sample by comparison to the other samples. It was also irregularly shaped, unlike the other samples which were simple squares. ER 5202-03. Finally, Dr. Maddox and Mr. Myers assumed that all of Sample 1 contained Cooper's blood. But, as noted above, they did not perform any tests on Sample 1, or its individual pieces, to confirm this assumption. Second, we can conclude that Dr. Siuzdak's EDTA results are very likely valid, based on analysis of Samples 2, 3 and 4. Samples 2, 3 and 4 were supposed to be control samples that contained no blood. Instead, they almost certainly contain significant amounts of blood. Further, it is likely that this blood was planted on the t-shirt. This may be seen if we look at both the DNA and the EDTA results for Samples 2, 3, 4 and 6. All four of these samples were taken from the t-shirt, and were supposed to have been control samples. (Sample 5 has inconclusive DNA results, so I put it to one side. Samples 7, 8, 9 and 10 are control samples that were not from the t-shirt, so I put them to one side also.) For Samples 2, 3, 4 and 6, we have a known amount of DNA and a known amount of EDTA. Samples 2, 3 and 4 all have significant amounts of DNA. Only Sample 6 has no DNA. For all four of these samples, there is a remarkably strong correlation between the amount of DNA in the sample and the amount of EDTA in the sample. The greater the amount of DNA in a sample, the greater the amount of EDTA in that sample. This holds true for the results of both Dr. Siuzdak and Dr. Ballard. This may be seen in two graphs, one for Dr. Siuzdak's results and one for Dr. Ballard's results: