Originally Posted by 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.