controls and alternate hypotheses
You've asked me this before and I've answered you.
OK. In that case, do I have you right that you believe it would have been standard practice to gather other items (spoons etc) from the drawer that Raffaele's kitchen knife was removed from? I don't mean to bang on about this, in fact I'd forgotten the discussion until you brought it up, but people keep discounting the knife in part because such controls were not done. As discussed I've seen no citations indicating this is how the police normally behave anywhere, just Steve Moore saying that in a different location they should have gathered up every knife.
shuttlt,
It seems to me that you are approaching this issue incorrectly. You are asking whether something is standard procedure, when you should be asking whether it makes good scientific sense to do so.
Let us consider the knife first.
Mark Waterbury wrote, “Perhaps even more important for the knife DNA, no control experiments were run to follow the handling of the item from the field through to the laboratory. That is, to see if other, random objects retrieved from the same drawer and handled in the same, unprofessional way, might also appear to have DNA on them.” To put it another way, finding Meredith’s DNA on any other object in the drawer falsifies the hypothesis that Meredith’s cells were on the kitchen knife prior to its collection.
Take the bra clasp, for another example. Mark Waterbury wrote, “Control experiments to check for this would have been simple. The clasp was retrieved from a pile of debris, shown in the picture, left by the fastidious investigators in Meredith’s room. Testing a few other items from that pile to see if they, too, had picked up DNA dust from the floor would tell us whether there was anything special about the clasp. Of course, that wasn’t done.”
Finally let us turn to the luminol footprints. Mark Waterbury wrote, “Amanda’s DNA was said to be found in one of these footprints. Did they also test a meter away from the footprints, to see if her DNA was all over the apartment where she lived?” Of course, the forensic police missed another important experiment with respect to the luminol-positive areas; specificly, they failed to report any confirmatory tests for blood.
Do these experiments make sense from a scientific standpoint? I believe that they do. Let me end with a quote I have probably given before. It comes from
Norah Rudin’s and Keith Inman’s list of the ten top ways to improve forensic science.
“1. Pose alternate hypotheses! Ask the right question!
Forensic scientists should aggressively pose alternate hypotheses. Hypothesis testing and comparison is the very core of science. The forensic scientist should actively assist the client to ask the right question(s) in the context of the case. The most brilliant answer to the wrong question will be irrelevant!” The whole list is well worth one’s time to digest.
You did answer the question about new evidence before but your answer veered off into a different direction than the one I imagined its taking.