Who killed Meredith Kercher? part 23

[TruthCalls]

As I said before, you are pulling those figures out of your ass. In fact, not just you but everyone is guessing about the sensitivity of the tests. Second, you are ignoring that luminol reacts with numerous other substances. Also, the so called luminol blobs are not prints, they are tracks and cannot be attributed to anyone. It is worthless.

The sensitivity of both Luminol and TMB are affected by numerous factors and the measured results can vary greatly. For Vixen to cite the absolute lowest sensitivity value I could find for TMB (1:10,000) and cite such high numbers for Luminol exposes a deliberate effort to mislead, as if we didn't already know the truth. There are dozens of research papers available that consistently show TMB capable of detecting blood at dilution levels as high as 1 part per million.

But what Vixen ignores is that even when blood is confirmed, unless it can be positively identified by DNA analysis it is useless. Imagine a crime scene where blood is detected and a sample is sent for DNA analysis. When the results come back they show it belongs to someone other than the victim but the investigators nonetheless go forward and claim it came from the victim. I'm guessing Italy might be the only civilized country on the planet that would allow that evidence to be introduced in court, let alone be accepted by two different sets of judges.

 

[acbytesla]

Here's what we know:

Stefanoni sprayed some luminol and immediately got bright flashes of reaction, with visibly concentrated hot spots. This is typical of luminol reacting with cleaners such as bleach, not latent blood.

She decided to run a TMB test.

The results were negative for every single sample.

She did not do any additional confirmatory testing of any kind.

IMO the conclusion is straightforward. She was suspicious based on the reaction that there wasn't latent blood but something else. She ran the TMB test to confirm her suspicion. No further testing was needed, she was satisfied ("you can be certain") it was not blood. She then mislead (lied) in court to help her employers.

Yes. That is the point. If Stefanoni was of the belief that the TMB produced a false negative result and still convinced that it was blood it would be incumbent for her to follow-up with some confirmatory test. Which she did not do. This is highly unprofessional.

How does anyone make an honest assessment that it is or isn't blood in light of totally contradictory results? Vixen attributes it to anecdotal guesses about the sensitivity of TMB. But that is patently dishonest and certainly isn't following the evidence. She isn't dismissing the negative TMB results for any other reason than she doesn’t like that result. It is her "faith" and nothing else.

 

[acbytesla]

The sensitivity of both Luminol and TMB are affected by numerous factors and the measured results can vary greatly. For Vixen to cite the absolute lowest sensitivity value I could find for TMB (1:10,000) and cite such high numbers for Luminol exposes a deliberate effort to mislead, as if we didn't already know the truth. There are dozens of research papers available that consistently show TMB capable of detecting blood at dilution levels as high as 1 part per million.

But what Vixen ignores is that even when blood is confirmed, unless it can be positively identified by DNA analysis it is useless. Imagine a crime scene where blood is detected and a sample is sent for DNA analysis. When the results come back they show it belongs to someone other than the victim but the investigators nonetheless go forward and claim it came from the victim. I'm guessing Italy might be the only civilized country on the planet that would allow that evidence to be introduced in court, let alone be accepted by two different sets of judges.

The problem of course is DNA is present without blood and the presence of Meredith's DNA can be expected all over her apartment. So, let's say you spray Luminol all over a room and get presumptive positive results and you follow it up with multiple TMB tests and they produce negative results, you also test for DNA and in one or more spots find the victim's DNA, does that mean it was actually blood after all? I don't think you can fairly reach that conclusion. There are much better tests that are considered confirmatory. I don't believe DNA is one of those tests.

 

[Vixen]

Do you actually work at being so wrong or does it come naturally?

There are dozens of studies available that document TMB being sensitive to blood up to 1:1,000,000. Luminol up to 1:5,000,000. Luminol is no doubt more sensitive but TMB is still considered sufficiently sensitive so as to be considered a confirmatory test (when negative, it's susceptibility to false positives, just as with Luminol, is what keeps it a presumptive test)

The prints were not identified and per court testimony they COULD NOT be identified.

Most of the prints either had no DNA or didn't have Meredith's DNA.

Testing with TMB does NOT nullify DNA analysis. There are dozens of research papers readily available that bear this out. I know you are bright enough to find this on your own but should you choose to feign ignorance I'll certainly be happy to provide several links.

You are trying to quote Stefanoni's court testimony and screwing it up royally. What Stefanoni claimed was that 50% of the traces she has identified with Luminol tested negative with TMB. She does not say that in those cases she performed confirmatory tests against the samples which tested negative and confirmed they were actually blood. So, what one could infer from this is that Luminol is actually very prone to false positives and the TMB results confirm this. I invite you to cite a credible research paper that suggests TMB has a 50% false negative rate though I can assure you I won't be holding my breath.

Luminol is the initial test of choice because it is extremely sensitive and can be sprayed over large areas at one time. No other reason. It remains a presumptive test and is prone to false positives. It can never be used alone as evidence of blood.

But you continue to ignore the elephant in the room. There are three footprint traces in Amanda's room which reacted to Luminol. These traces tested negative for blood using TMB. But even more damning for the prosecution is that they tested positive for Amanda's DNA but not Meredith's. So what does this mean? Well, it means whatever made the print was not broken down with bleach because Amanda's DNA was present. And since there was no known source of blood from Amanda that could have resulted in her leaving three prints in her own room, there can only be one logical conclusion - the prints were made by something other than blood, and certainly something other than Meredith's blood.

Your contortionist efforts to claim a TMB negative, DNA negative trace is still Meredith's blood is almost as entertaining as your claiming scientists are honest and ethical but judges are not, except when we are discussing scientists who find in favor of Amanda and Raffaele, such as C&V (and, I assume, Gil, Hampikian, Waterbury, etc.) in which case they to become corrupt as well.

From Wiki:

Luminol is a white-to-pale-yellow crystalline solid that is soluble in most polar organic solvents, but insoluble in water.

Forensic investigators use luminol to detect trace amounts of blood at crime scenes, as it reacts with the iron in haemoglobin. Biologists use it in cellular assays to detect copper, iron, and cyanides, as well as specific proteins by western blot.

In other words, some plants, especially brightly coloured ones, contain zeaxanthin, lypsocines, lutein, carotine, etc and some of these substances react to chemiluminescence which can be catalysed by adding luminol to a hydrogen peroxide solution. If night photography s set up (complete darkness) then this luminous flash can be capture on film.

It is highly unlikely that coinciding with a bloody murder Amanda and Raff dipped their feet in any of these substances. The objective truth is and as captured on film, is that footprints identified as Amanda's and Raff's by experts who applied intricate engineering tools and precise measurements to do so.


From wiki

Drawbacks[edit]
Luminol has drawbacks that can limit its use in a crime scene investigation:

Luminol chemiluminescence can also be triggered by a number of substances such as copper or copper-containing chemical compounds,[13] and certain bleaches. As a result, if someone cleans a crime scene thoroughly with a bleach solution, residual cleaner makes the entire crime scene produce the typical blue glow, which effectively camouflages organic evidence such as blood.
Horseradish sauce, via the enzyme horseradish peroxidase, catalyses the oxidation of luminol, emitting light at 428 nm (blue in the visible spectrum), which may result in a false positive.
Luminol can detect the small amount of blood present in urine, and can be distorted if animals' urine is present in the room being tested.
Luminol reacts with faecal matter, causing the same glow as if it were blood.
Luminol's presence may prevent other tests from being performed on a piece of evidence. However, it has been shown that DNA can be successfully extracted from samples treated with luminol reagent.[14]
Excessive smoke in an enclosed space—e.g., a car that someone frequently smokes in—can cause positive results with Luminol.[12]

You are really reaching to claim the above factors were involved.

 

[Vixen]

The sensitivity of both Luminol and TMB are affected by numerous factors and the measured results can vary greatly. For Vixen to cite the absolute lowest sensitivity value I could find for TMB (1:10,000) and cite such high numbers for Luminol exposes a deliberate effort to mislead, as if we didn't already know the truth. There are dozens of research papers available that consistently show TMB capable of detecting blood at dilution levels as high as 1 part per million.

But what Vixen ignores is that even when blood is confirmed, unless it can be positively identified by DNA analysis it is useless. Imagine a crime scene where blood is detected and a sample is sent for DNA analysis. When the results come back they show it belongs to someone other than the victim but the investigators nonetheless go forward and claim it came from the victim. I'm guessing Italy might be the only civilized country on the planet that would allow that evidence to be introduced in court, let alone be accepted by two different sets of judges.

The source of my information comes from a good authority.

 

[TruthCalls]

The problem of course is DNA is present without blood and the presence of Meredith's DNA can be expected all over her apartment. So, let's say you spray Luminol all over a room and get presumptive positive results and you follow it up with multiple TMB tests and they produce negative results, you also test for DNA and in one or more spots find the victim's DNA, does that mean it was actually blood after all? I don't think you can fairly reach that conclusion. There are much better tests that are considered confirmatory. I don't believe DNA is one of those tests.

No disagreement there. However, the point I'm making is; even if proper follow-up confirmatory testing wasn't done to confirm whether this was blood or not, it DID still undergo DNA analysis and Meredith's DNA was not found. So this confirms that they were getting Luminol hits that are provably NOT Meredith's blood. I'm satisfied it wasn't blood because false negatives by TMB are rare, but more importantly, it proves that whatever it is it did not come from Meredith. This proves that Luminol is reacting to something other than Meredith's blood, and that was all the defense needed to show.

But to your point, I do believe DNA can be considered a confirmatory test that blood is NOT present, much as TMB (and Luminol) are. If DNA IS there it could be something other than blood, but if it isn't there then it's extremely unlikely (perhaps definitive) not to be blood. And on that... some of the traces had no DNA at all.

 

[Vixen]

Yes. That is the point. If Stefanoni was of the belief that the TMB produced a false negative result and still convinced that it was blood it would be incumbent for her to follow-up with some confirmatory test. Which she did not do. This is highly unprofessional.

How does anyone make an honest assessment that it is or isn't blood in light of totally contradictory results? Vixen attributes it to anecdotal guesses about the sensitivity of TMB. But that is patently dishonest and certainly isn't following the evidence. She isn't dismissing the negative TMB results for any other reason than she doesn’t like that result. It is her "faith" and nothing else.

Faith or lack thereof has nothing to do with it. Stefanoni is a hard hat scientist with no interest in framing innocent kids to life imprisonment instead of the real killers. She ran the tests in a cold scientific way and is simply reporting the cold scientific results. sure, it inolves some interpretation, that only comes with experience. We know that Stefanoni is extremely experienced and beat of stiff competition for her role as head of her team.

If you believe Stefanoni rigged it, you need to present your rationale.

 

[Vixen]

The problem of course is DNA is present without blood and the presence of Meredith's DNA can be expected all over her apartment. So, let's say you spray Luminol all over a room and get presumptive positive results and you follow it up with multiple TMB tests and they produce negative results, you also test for DNA and in one or more spots find the victim's DNA, does that mean it was actually blood after all? I don't think you can fairly reach that conclusion. There are much better tests that are considered confirmatory. I don't believe DNA is one of those tests.

What is it with the PIP they keep using the phrase, 'all over'?

Nobody's DNA was 'all over' anything.

 

[acbytesla]

The source of my information comes from a good authority.

Personally, I don't have that high of an opinion about <SNIP>.

Edited by Locknar: 

SNIPed, breach of rule 0.

 

[TruthCalls]

From Wiki:



In other words, some plants, especially brightly coloured ones, contain zeaxanthin, lypsocines, lutein, carotine, etc and some of these substances react to chemiluminescence which can be catalysed by adding luminol to a hydrogen peroxide solution. If night photography s set up (complete darkness) then this luminous flash can be capture on film.

It is highly unlikely that coinciding with a bloody murder Amanda and Raff dipped their feet in any of these substances. The objective truth is and as captured on film, is that footprints identified as Amanda's and Raff's by experts who applied intricate engineering tools and precise measurements to do so.


From wiki



You are really reaching to claim the above factors were involved.

Damn you can be dense. Once more... it does not matter how unlikely something might be - science is science. TMB is very sensitive and very reliable wrt negative readings. DNA analysis is also very accurate. A trace that tests negative with TMB and negative for Meredith's DNA is NOT made from Meredith's blood. You can go round and round all you want but you're convincing no one but yourself.

 

[Vixen]

Damn you can be dense. Once more... it does not matter how unlikely something might be - science is science. TMB is very sensitive and very reliable wrt negative readings. DNA analysis is also very accurate. A trace that tests negative with TMB and negative for Meredith's DNA is NOT made from Meredith's blood. You can go round and round all you want but you're convincing no one but yourself.

The excerpt bagels presented, supposedly 'proving' Stefanoni said the TMB was negative, is extremely tenuous, as Stefanoni almost certainly said nothing of the sort and definitely not in the context claimed.

 

[bagels]

Faith or lack thereof has nothing to do with it. Stefanoni is a hard hat scientist with no interest in framing innocent kids to life imprisonment instead of the real killers. She ran the tests in a cold scientific way and is simply reporting the cold scientific results. sure, it inolves some interpretation, that only comes with experience. We know that Stefanoni is extremely experienced and beat of stiff competition for her role as head of her team.

If you believe Stefanoni rigged it, you need to present your rationale.

No, you believe the results were rigged.

We believe the luminol was bad evidence, and the actual results reflect that, an acquittal.

It is not 2009. Stop posting like it's 2009. You need to supply evidence that the luminol results should have been strong evidence of criminal involvement. For example, by tracking down a neutral expert and having them give their opinion. BTW the PIP actually did this when the trial was in progress and two expert scientists said they found the samples all being blood below the threshold of TMB's detection limit less plausible than the samples being something other than blood.

The PGP's approach to this case post 2015 is extremely confused. You are now the one with a burden of proof to overcome proving corruption and proving the prosecution made their case. The PIP spent years on that side of the fence so maybe you could ask them for pointers

 

[acbytesla]

No disagreement there. However, the point I'm making is; even if proper follow-up confirmatory testing wasn't done to confirm whether this was blood or not, it DID still undergo DNA analysis and Meredith's DNA was not found. So this confirms that they were getting Luminol hits that are provably NOT Meredith's blood. I'm satisfied it wasn't blood because false negatives by TMB are rare, but more importantly, it proves that whatever it is it did not come from Meredith. This proves that Luminol is reacting to something other than Meredith's blood, and that was all the defense needed to show.

But to your point, I do believe DNA can be considered a confirmatory test that blood is NOT present, much as TMB (and Luminol) are. If DNA IS there it could be something other than blood, but if it isn't there then it's extremely unlikely (perhaps definitive) not to be blood. And on that... some of the traces had no DNA at all.

I'm not sure you can. I'm pretty sure I've read that red blood cells do not carry much DNA. Maybe Chris or someone else can weigh in.

 

[TruthCalls]

Faith or lack thereof has nothing to do with it. Stefanoni is a hard hat scientist with no interest in framing innocent kids to life imprisonment instead of the real killers. She ran the tests in a cold scientific way and is simply reporting the cold scientific results. sure, it inolves some interpretation, that only comes with experience. We know that Stefanoni is extremely experienced and beat of stiff competition for her role as head of her team.

If you believe Stefanoni rigged it, you need to present your rationale.

My apologies Vixen, I didn't realize you had a personal, professional relationship with Stefanoni and can attest to the quality and honesty of her work. How this appears to me is; if Vixen feels someone supports the argument for guilt then that someone is honest, ethical and qualified but if they support an argument for innocence then they are dishonest, unethical and unqualified. You do this consistently, be it law enforcement, lawyers, judges, scientists, authors, etc.

So yes, she ran the tests. She ran a TMB test, got a negative result and decided to disregard the results. She then ran a DNA test, it indicated Meredith's DNA was not present and she decided to disregard the results. I'm glad you're impressed with her professionalism but personally, with behavior like this, I don't think she should be trusted in the mail room let alone leading up a lab.

 

[Vixen]

No disagreement there. However, the point I'm making is; even if proper follow-up confirmatory testing wasn't done to confirm whether this was blood or not, it DID still undergo DNA analysis and Meredith's DNA was not found. So this confirms that they were getting Luminol hits that are provably NOT Meredith's blood. I'm satisfied it wasn't blood because false negatives by TMB are rare, but more importantly, it proves that whatever it is it did not come from Meredith. This proves that Luminol is reacting to something other than Meredith's blood, and that was all the defense needed to show.

But to your point, I do believe DNA can be considered a confirmatory test that blood is NOT present, much as TMB (and Luminol) are. If DNA IS there it could be something other than blood, but if it isn't there then it's extremely unlikely (perhaps definitive) not to be blood. And on that... some of the traces had no DNA at all.

Let's go to the court testimony.

A consultant, Sarah Gino is cross-examined:

[re TMB]

About the latter argument is ... is negative quell'accertamento if blood or other material that still reacts to the TMB that exam but appears to have been found Amanda's DNA on those tracks we're talking about ?
SG:
Then aspects that I go to my slide because that memory could say things that are not correct, then we have found for example, 178 tells us that from that material was extracted a profile of Knox, 179 ditto, ditto 180.

and:

At least it was not possible to establish that it was blood, though I say confirms that found DNA of Knox?
SG:
Of course, the genetic profile of Knox was found.MC:
Okay and about always of this TMB, this analysis at the level percentage in his experience, this analysis made on tracks with enhanced luminol are more cases in which the analysis is negative, this type of ... is negative TMB or are more cases in which is positive?
SG:
So, I would say that we can say is a 50 per cent because some times the luminol gives positive traces that in reality the TMB are negative and other times ... I would say a 50 and 50 I can neither say yes or say no to a side or the other.
GCM:
Excuse me, maybe TMB if we can give explanations?
SG:
And 'tetramethylbenzidine TMB, is an acronym that is ...

http://themurderofmeredithkercher.com/Sarah_Gino's_Additional_Testimony


Note: 50% chance of a false positive or a positive negative.

You said I was making these figures up. So not only Stefanoni testified that TMB has this reputation, but consultant S Gino is saying it, too.


Please retract your claim.

 

[TruthCalls]

I'm not sure you can. I'm pretty sure I've read that red blood cells do not carry much DNA. Maybe Chris or someone else can weigh in.

Red blood cells carry no DNA, but short of a lab procedure, how would you remove the white blood cells from a blood sample collected at a crime scene? And even if there are ways that this could happen, the net effect is the same. If you can't find DNA then you can't identify who it came from and therefore it carries no investigative value. That is, unless assumption and speculation is considered sufficient in a court of law.

 

[Vixen]

I'm not sure you can. I'm pretty sure I've read that red blood cells do not carry much DNA. Maybe Chris or someone else can weigh in.

Red blood cells carry no DNA as they are not nucleated.

 

[acbytesla]

What is it with the PIP they keep using the phrase, 'all over'?

Nobody's DNA was 'all over' anything.

Of course it is. Your DNA can be expected all over areas where you spend time. That's why where it is found is very important.

It's all about context. Amanda and Meredith lived in that apartment and spent plenty of time there. So regardless of where you might find Amanda's or Meredith's DNA in that apartment it is problematic to draw any incriminating conclusion. The same may not be said about finding the DNA from Rudy because he is not known to spend any time upstairs in the cottage.

This is not rocket science.

 

[TruthCalls]

Let's go to the court testimony.

A consultant, Sarah Gino is cross-examined:

[re TMB]




and:

http://themurderofmeredithkercher.com/Sarah_Gino's_Additional_Testimony


Note: 50% chance of a false positive or a positive negative.

You said I was making these figures up. So not only Stefanoni testified that TMB has this reputation, but consultant S Gino is saying it, too.


Please retract your claim.

Why would I retract my claim? They are referring to how often TMB provides a negative result to a Luminol positive trace. Neither one of them is opining on how often a Luminol trace was PROVEN to be blood yet received a negative TMB result. You need to work on your comprehension.

As an aside, since TMB is STILL a preferred method as a test for blood, if it was faulty upwards of 50% of the time do you honestly think it would still be used? Have you done ANY research on TMB to better understand not only it's sensitivity but it's lack of propensity for false negatives? That was a rhetorical question, btw.

And for what purpose are you highlighting that Amanda's DNA was found. The whole point of this debate is that the Luminol traces were not made from Meredith's blood. Finding Amanda's DNA does not in any way alter that conclusion - in fact, it re-enforces it.

 

[acbytesla]

Red blood cells carry no DNA, but short of a lab procedure, how would you remove the white blood cells from a blood sample collected at a crime scene? And even if there are ways that this could happen, the net effect is the same. If you can't find DNA then you can't identify who it came from and therefore it carries no investigative value. That is, unless assumption and speculation is considered sufficient in a court of law.

I don't think you can, but isn't the quantity of white blood cells small?

While i agree with you that without DNA, we can't make an attribution, that isn't the hypothesis I'm suggesting. I'm just saying that the failure to find DNA in a presumptive positive luminol area does not mean it isn't blood. But, I am by no means an expert.