Kentucky school fire forensic case

SEM operator reported fourteen percent technetium in roofing nails. Tom uses it to skewer credulity in chemical analyses: "we can settle this case, we just sell the nails for the technetium."

So they give you a little radioactive technetium, and it's decaying rapidly enough that they can see where the blood vessels are, because the technetium's running through your blood. If you have a blockage in your heart, they can say, we saw something before and there was a blood vessel there, and now we don't see the blood vessel, which means blood is not flowing through. I had a case once where a school burned down in Kentucky, and the people did an analysis in the scanning electron microscope and came up with an analysis that said there was fourteen percent technetium in the roofing nails. I thought, well, we can settle this case — we just sell the nails for the technetium. It just shows you how good some chemical analyses are. Thanks for that expert.

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