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Old 17th November 2020, 07:04 AM   #531
Chris_Halkides
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not bleach and not bleach-cleaned blood

Originally Posted by JTF View Post
Again, my reference was to the photographs taken of this particular area of Avery's garage. If you felt mislead, I apologize, but the photographs clearly depict a glowing portion of the garage floor. You nor I have any expertise in determining the reason or reasons for the luminol reaction, yet it appears that even the prosecution/defense experts didn't have a definitive explanation for this reaction. What is not in dispute is that the day after Halbach's disappearance, Avery took the day off from work, he asked his nephew to assist him with cleaning the garage floor with bleach, and that the jeans worn by Dassey contained several bleach stains. A ballistics expert for the prosecution matched a bullet found in Avery's garage to a rifle located on the wall over Avery's bed, Halbach's DNA was found on the bullet, and so on and so forth.
JTF,

We know that the luminol reaction was not due to bleach (Creamer J.I., et al., Luminescence 2005; 20: 411–413, the citation that was previously given). When known blood on concrete is cleaned with bleach, the phenolphthalein test (the Kastle-Meyer test) is still positive. See Table 1, bottom entry in Gross AM, Harris KA, Kaldun GL. "The effect of luminol on presumptive tests and DNA analysis using the polymerase chain reaction." J Forensic Sci 1999; 44(4):837–840. It is very difficult to see how bleach could destroy iron ions, and first-row transition metal ions often give false positives in presumptive tests for blood. Yet in the Avery garage the K-M test gave a negative result. Therefore, we know that the luminol-positive area was not likely to be bleached-cleaned blood. Please speak for yourself when it comes to expertise. Also, expertise is not the same as detailed knowledge. I agree that the substance in question has not yet been identified.
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Last edited by Chris_Halkides; 17th November 2020 at 07:52 AM.
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