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Analyzing the Evidence Evidence is examined in the criminalistics lab The smaller the amount of evidence, the more difficult it is to do species identification. Should the evidence be no more than scrapings from a blood stain found in the back of a pick-up truck, the sample will go directly to the serology section where protein and DNA analyses are performed to determine the family, species, individual and gender of the victim. Body parts, blood, tissue and non-animal evidence--rope fiber, bullets, poisons, pesticides, chips, and oriental potions--are sent to the Criminalistics Section where advanced analytical techniques and traditional forensic methods are called into play. We use two HP 5890 gas chromatographs (GCs)--one with a nitrogen-phosphorus detector--to characterize small volatile molecules. This technique is particularly well-suited for the characterization and confirmation of pesticides such as organophosphates. It also is used for the chemical analysis of poisons as well as oil and musk characterizations. For the most part we use an HP 1090 high performance liquid chromatography (HPLC) with diode array detector (DAD) controlled by an HP ChemStation program for bile identification. Using this system, we are able to distinguish between the bile of bears, pigs, and other species. We also use this configuration to analyze samples for the presence of strychnine. Other instruments in the Criminalistics Section include Fourier transform infrared (FTIR) and microscope FTIR spectrophotometers for determining keratin and fiber identification. We also have a scanning electron microscope (SEM) that we use for inorganic analysis of evidence such as paint chips and for enlarging firing pin impressions on cartridges to show that the continuity of striations is consistent with the striations made by a suspect's weapon. P  A  R  T    3    O  F    4 Next: Making a Case Previous: The Mystery Unfolds A Story of Greed Then there is the questionable survival of the North American black bear. Dealers in illegal Oriental medicines have succeeded in decimating Asian bear populations. With bear gall bladders up to $40,000 on the Korean black market (as opposed to the US market which pays only $150 for a bear gall bladder), poachers have been looking to North American bears as a fresh source. Imagine their delight when nature presented the perfect fraud: similar morphology between the gall bladder of a bear and a pig make the two virtually indistinguishable. In fact, the vast majority (80%) of gall bladder samples taken in Asia have been found to be from domestic pigs. Compare this to samples taken in the U.S., where 18% were from bears and 82% from pigs; and to samples from Canada, where 96% were from North American black bears. Using an HP 1090 HPLC, the lab is now able to identify three distinct bile acids found only in bear gall-- ursodeoxycholytaurine, chenodeoxycholyltaurine, and cholyltaurine. At times, the chemists at the lab need to identify small amounts of tissue or blood