Continuation Part 11: Amanda Knox/Raffaele Sollecito

[Desert Fox]

Should we abolish juries? Are you suggesting a panel of scientists should preside over legal cases?

It is the judge's job, or suppose to be, to study on the science. He or she needs to verify that the science is solid before it is presented to a jury. The judges in many jurisdictions have looked at the science and have stated that luminol is not evidence of blood and must be confirmed. This science is then taught / confirmed in education in forensics.

 

[acbytesla]

Fortunately, most juries aren't likely deluded into thinking that the lack of a confirmatory test means the substance wasn't blood when they are presented testimonies from experts on both sides.

Fortunately? Fortunately for whom? It certainly doesn't benefit Italy or its judicial system in this case. Or Amanda and Raffaele.

Deluded? What is deluded is thinking that just because Luminol reacts, it must be blood. This is a perfect example of "prejudicial evidence" that would never be shown to an American jury. It presents a powerful picture which may and in very probably is incredibly misleading given the multiple negative TMB tests.

This is the kind of thing that was constantly allowed in this case. Instead of presenting evidence, the Italian system allowed prejudicial narratives and wild speculation.

 

[acbytesla]

Should we abolish juries? Are you suggesting a panel of scientists should preside over legal cases?

On the contrary. But there are certain things that shouldn't be left up to juries. The weight of the scientific forensic community has spoken very loudly about the value of Luminol testing. It is a good investigative tool, but it is a presumptive test for blood only. Using it as evidentiary proof of blood in a court of law is a misuse of this tool.

I'd have a problem with it being used even if there were no negative TMB tests and no confirmatory tests, but it is a true disgrace to use it in this case with the contradictory results from the TMB.

Should the jury just flip a coin? Even though if you presented those same results to a thousand forensic scientists 999 of them would dismiss the likelihood that it was blood?

 

[griffinmill]

The weight of the scientific forensic community has spoken very loudly about the value of Luminol testing.

You seem to have caught the Halkides disease in believing that the studies he quotes, largely authored by professional defense experts, represent the larger scientific community.

Meanwhile, cases go on where juries hear the actual scientific evidence regarding luminol and forensics, from both sides, and make informed decisions as to its weight.

 

[Diocletus]

Not the point. No scientist alive would conclude definitively that luminol is proof of blood. And no doubt every scientist, specific to the question of whether a substance can be proven as blood, would require confirmation.

A legal case does not require scientific certainty of blood, however. And the question isn't confirmation, but rather whether there is a substance other than blood that the luminol could have reacted to, and what the likelihood of that is.

A jury decides this, and every case is different.

Oh good, then you must have that case that we've been looking for. You know, the case where luminol spots negative to TMB and dna have been used to convict.

 

[acbytesla]

You seem to have caught the Halkides disease in believing that the studies he quotes, largely authored by professional defense experts, represent the larger scientific community.

That is a total misrepresentation of the facts.

Meanwhile, cases go on where juries hear the actual scientific evidence regarding luminol and forensics, from both sides, and make informed decisions as to its weight.

Where? Name the cases. Also, name the cases where it is accepted despite contradictory secondary presumptive or confirmatory tests. The reality is even Stefanoni said the negative TMB tests means the substance is NOT blood.

 

[griffinmill]

Oh good, then you must have that case that we've been looking for. You know, the case where luminol spots negative to TMB and dna have been used to convict.

I assume you also know of lots of cases where luminol was thrown out on the basis of a negative TMB test? Or why the luminol wasn't immediately thrown out in this case for that reason?

Maybe you'll cite that Georgia case. Where luminol was thrown out, at least partially on the basis of a lack of confirmatory test. The same one where the defendant confessed, and the luminol was retroactively proved to be valid.

 

[Desert Fox]

I thought I would post this (Thanks to TomG)
http://the-gist.org/2011/03/seeing-red-–-presumptive-tests-for-blood/

Reading the whole thing is a good idea but this is solid:

Daring to presume

All of the techniques described in this article are classed as presumptive tests. This is because they are prone to false positives so, while a negative result is assumed to mean that blood is not present, a positive result is a presumptive positive for blood and further analytical methods are required to confirm that blood is present. A negative result should be confirmed by using a positive control (for example a known blood sample) as the liquid solutions used in these presumptive tests are susceptible to degradation.

Once you have a presumptive positive for blood as well as analysis to confirm the sample is blood, you need to determine whether or not the blood is human and then you can move on to the process of attempting to discover who the blood came from.

So, magic detection sprays do exist, but sadly they do not provide all the answers that they appear to on the television. For that, more scientific analysis is required.

 

[Diocletus]

Maybe you'll cite that Georgia case. Where luminol was thrown out, at least partially on the basis of a lack of confirmatory test. The same one where the defendant confessed, and the luminol was retroactively proved to be valid.

The Georgia case is just a court following the law. Sometimes you can't use evidence, like coerced confessions, because it is unreliable, unfair or illegal.

But, that's all just a distraction. I'm looking for the case where luminol negative to TMB and dna sends someone to jail. The Georgia case is the opposite.

 

[griffinmill]

The Georgia case is just a court following the law. Sometimes you can't use evidence, like coerced confessions, because it is unreliable, unfair or illegal.

But, that's all just a distraction. I'm looking for the case where luminol negative to TMB and dna sends someone to jail. The Georgia case is the opposite.

Or, alternatively, in the Georgia case luminol evidence that should have been admitted wasn't allowed to be weighed by a jury.

Your argument that cases don't exist with luminol positive and further confirmatory tests negative is inherently flawed.

If that was the case, AK/RS attorneys would merely have to point that out. But apparently, luminol interpretation isn't as simplistic as you'd like it to be.

 

[Numbers]

You seem to have caught the Halkides disease in believing that the studies he quotes, largely authored by professional defense experts, represent the larger scientific community.

Meanwhile, cases go on where juries hear the actual scientific evidence regarding luminol and forensics, from both sides, and make informed decisions as to its weight.

griffinmill,

You seem to be mistaking the forensic science community as being composed only of "professional defense experts".

Could you please present some citations from professional forensic scientists stating that one should interpret or understand a luminol test, not followed by any confirmatory test for blood, as definitely indicating the presence of blood?

The luminol test is actually a presumptive test for blood, and may react to many non-blood common substances, including traces of iron and other metals. Soil, which of course may be present on the soles of shoes or feet (depending where you've walked last) often contains traces of metals includiing iron (particularly in the Italian province of Umbria, the original source of umber, and where Perugia is located). Cleaning products also often contain materials that will react with lulminol.

Here's a simple analogy to forensic blood testing: eating. It's a multistep process. One must chew, swallow, and digest. If a 2-year only chews his/her food and then spits it all out without swallowing, one can't say that the 2-year old has eaten. For forensic blood testing, the luminol helps find where the blood may be; a confirmatory test, such as an antibody-antigen test (which is highly sensitive and selective, but is a spot rather than area test) is required to complete the test.

 

[moije2]

Presumptive?

I thought I would post this (Thanks to TomG)
http://the-gist.org/2011/03/seeing-red-–-presumptive-tests-for-blood/

Reading the whole thing is a good idea but this is solid:

Daring to presume

All of the techniques described in this article are classed as presumptive tests. This is because they are prone to false positives so, while a negative result is assumed to mean that blood is not present, a positive result is a presumptive positive for blood and further analytical methods are required to confirm that blood is present. A negative result should be confirmed by using a positive control (for example a known blood sample) as the liquid solutions used in these presumptive tests are susceptible to degradation.

Once you have a presumptive positive for blood as well as analysis to confirm the sample is blood, you need to determine whether or not the blood is human and then you can move on to the process of attempting to discover who the blood came from.

So, magic detection sprays do exist, but sadly they do not provide all the answers that they appear to on the television. For that, more scientific analysis is required.

Reading all this stuff about "presumptive" tests and the debate from the guilt faction which argues that the blobs etc found on the floor must be "presumed" from the positive luminol tests to be blood unless you can find (prove?) another plausible explanation for the positive reaction, then it must be blood. Isn't that their argument? And recently they have buttressed this argument with the idea that since the blobs are close in proximity to known blood then these too must be blood. (Forget that they are also close to a rusty heater.)

I am hearing this word "presumptive" echoing in my head. Why is it called presumptive? Presumptive of blood? Is that really why it is called that? Perhaps there should be a better description or label for the use of that test. Perhaps initial filter of some sort? I am thinking that the "presumptive" part of this is inaccurate, and could just as easily be described as "presumptive" of chlorine, rust, plant etc. This name reeks of "until proven otherwise".

What thinkest thou, my fine skeptics? Is the name of the tests - presumptive - being tossed about not appropriate?

 

[Numbers]

Or, alternatively, in the Georgia case luminol evidence that should have been admitted wasn't allowed to be weighed by a jury.

Your argument that cases don't exist with luminol positive and further confirmatory tests negative is inherently flawed.

If that was the case, AK/RS attorneys would merely have to point that out. But apparently, luminol interpretation isn't as simplistic as you'd like it to be.

On the contrary, you are pointing out the error in a particular court's judgment.

 

[Charlie Wilkes]

You seem to have caught the Halkides disease in believing that the studies he quotes, largely authored by professional defense experts, represent the larger scientific community.

Meanwhile, cases go on where juries hear the actual scientific evidence regarding luminol and forensics, from both sides, and make informed decisions as to its weight.

I assume you also know of lots of cases where luminol was thrown out on the basis of a negative TMB test? Or why the luminol wasn't immediately thrown out in this case for that reason?

Maybe you'll cite that Georgia case. Where luminol was thrown out, at least partially on the basis of a lack of confirmatory test. The same one where the defendant confessed, and the luminol was retroactively proved to be valid.

??? Ignorance may be bliss, but it is still ignorance.

Anyone who knows anything about this subject can easily cite "lots of cases" where misrepresentation of presumptive blood tests has been flagged as a problem in a criminal trial. It just takes time to look them up.

Here is a brief article about a crime lab audit where the focus was on that very subject:

http://www.newsobserver.com/2010/08/19/635632/scathing-sbi-audit-says-230-cases.html

This audit was not commissioned by defense lawyers. It was commissioned by a state attorney general. I can find the full audit report itself, or you can find it yourself if you care. I'm not going to bother looking if you don't care, which seems to be the case.

As for Halkides... he is a professor of biochemistry, which is why he took a particular interest in how luminol was used in the Meredith Kercher case. What are your credentials?

 

[griffinmill]

Could you please present some citations from professional forensic scientists stating that one should interpret or understand a luminol test, not followed by any confirmatory test for blood, as definitely indicating the presence of blood?

Could you please explain why, if this was universally accepted as true, that RS/AK attorneys didn't just rest their case on this unassailable fact? Or why the judges, in the face of this incontrovertible evidence, didn't throw the luminol out?

Do you think maybe, just maybe, the larger scientific community debates the arguments you consider as self evident scientific doctrine?

 

[Diocletus]

Your argument that cases don't exist with luminol positive and further confirmatory tests negative is inherently flawed.

If that was the case, AK/RS attorneys would merely have to point that out. But apparently, luminol interpretation isn't as simplistic as you'd like it to be.

Why? Because a couple if Italian judges were so far as we know the only ones on the world who have ever relied on TMB/dna negative luminol hits to convict somebody?

 

[Diocletus]

Could you please explain why, if this was universally accepted as true, that RS/AK attorneys didn't just rest their case on this unassailable fact? Or why the judges, in the face of this incontrovertible evidence, didn't throw the luminol out?

Yeah. The judges were dumbasses.

 

[griffinmill]

Why? Because a couple if Italian judges were so far as we know the only ones on the world who have ever relied on TMB/dna negative luminol hits to convict somebody?

As I expected. The whole world knows what you think is true, but Italy doesn't.

Additionally, Italy also ignored the fact that every other nation in the world accepts that luminol without confirmatory testing is worthless.

Yet AK/RS attorneys vaguely argued this obvious fact, and the global scientific community has been largely silent in watching it unfold.

 

[Charlie Wilkes]

Reading all this stuff about "presumptive" tests and the debate from the guilt faction which argues that the blobs etc found on the floor must be "presumed" from the positive luminol tests to be blood unless you can find (prove?) another plausible explanation for the positive reaction, then it must be blood. Isn't that their argument? And recently they have buttressed this argument with the idea that since the blobs are close in proximity to known blood then these too must be blood. (Forget that they are also close to a rusty heater.)

I am hearing this word "presumptive" echoing in my head. Why is it called presumptive? Presumptive of blood? Is that really why it is called that? Perhaps there should be a better description or label for the use of that test. Perhaps initial filter of some sort? I am thinking that the "presumptive" part of this is inaccurate, and could just as easily be described as "presumptive" of chlorine, rust, plant etc. This name reeks of "until proven otherwise".

What thinkest thou, my fine skeptics? Is the name of the tests - presumptive - being tossed about not appropriate?

I think "presumptive blood test" is a fine appellation. It accurately describes how luminol is used at crime scenes, when it is used properly, i.e. to develop meaningful evidence.

Here is a case where it was used properly:

http://www.cbsnews.com/news/two-wiv...cious-accidents-was-it-coincidence-or-murder/

Investigators got a luminol result that they presumed was blood because its location and appearance fit with a scenario in which their suspect bludgeoned his wife, loaded her into a car, and then staged an accident to make it look like that was what killed her.

Having found these latent stains, they took their swabs back to the lab. Sure enough - the substance was confirmed to be blood, and in fact it was confirmed to be the victim's blood.

Contrast with the Meredith Kercher investigation, where the presumptive test did not check out in the lab, and the traces themselves do not fit with any plausible theory of the crime - to the point where "Machiavelli" is explaining them by saying Amanda/Raffaele slid around the crime scene on bathmats after committing the murder.

I kid you not. I have been pestering him to elaborate, but he knows better than to take that challenge.

The problem is not that the nomenclature is wrong. The problem is that the guilt faction interprets "presumptive" to mean "definitive" or "conclusive." I don't know what can be done about that.

 

[Numbers]

Could you please explain why, if this was universally accepted as true, that RS/AK attorneys didn't just rest their case on this unassailable fact? Or why the judges, in the face of this incontrovertible evidence, didn't throw the luminol out?

Do you think maybe, just maybe, the larger scientific community debates the arguments you consider as self evident scientific doctrine?

If any such debate were going on, you would be able to produce citations of it.

You may also wish to claim that there is a debate in the larger scientific community as to whether or not the earth is round. Based on your ideas about luminol and rejection of empirical science, you would certainly be in the flat-earth believers; apparently that is your form of "skepticism."