Blood spatter? Fact or myth?

[Jean-Pierre]

OK - have managed to find a version of the paper here.

http://projects.nfstc.org/workshops/resources/literature/Amplification/35_The%20Effect%20of%20Luminol%20on%20Presumptive%20Tests%20and.pdf

Whilst on the subject, the following explanation of LCA DNA may be helpful. (Apologies for cut and paste)   

DNA
The standard DNA test (SGM+) is used where an identifiable stain such as blood or semen is found. The smallest bloodstain visible with the naked eye (c. 50 - 100 cells) contains enough DNA for this test.
This analyses eleven areas (also called markers or loci) of DNA, consisting of ten variable areas and a sex test.
These areas are copied 28 times and instrumental analysis used to capture and analyse the result.
This test is used to produce DNA profiles for adding to the National DNA Database (NDNAD).
This type of test is used worldwide, and a variety of commercial systems looking at different areas (markers, loci) of DNA are available.
Some samples are invisible to the naked eye, in poor condition due to external factors e.g. fire and water, or have been retained from crimes that occurred many years ago. These may have too little DNA for the standard test to be successful.

Top of page

How the Low Copy Number (LCN) technique works
The LCN test is based upon the same scientific principles as the standard SGM+
test, with variations designed to increase the sensitivity of the process, including copying the DNA sample 34 times rather than the standard 28.
The test can obtain a profile from as few as 5 - 10 cells, or from DNA that is in poor condition. This could be the amount of DNA left on a cup by drinking from it or on a pen by writing with it.
This increased sensitivity means ultra-clean laboratories are needed for the testing to minimise contamination of the sample by DNA from any other source.
Rather than performing a separate quantitation stage, a dilution stage is now included routinely to ensure that nothing else present in the sample has caused the result to be lost.

[Mr Gray]

Every house is full of cellular material
Exfoliated skin is a constituent of dust

[ShiningInLuz]

OK - have managed to find a version of the paper here.

http://projects.nfstc.org/workshops/resources/literature/Amplification/35_The%20Effect%20of%20Luminol%20on%20Presumptive%20Tests%20and.pdf

Whilst on the subject, the following explanation of LCA DNA may be helpful. (Apologies for cut and paste)   

DNA
The standard DNA test (SGM+) is used where an identifiable stain such as blood or semen is found. The smallest bloodstain visible with the naked eye (c. 50 - 100 cells) contains enough DNA for this test.
This analyses eleven areas (also called markers or loci) of DNA, consisting of ten variable areas and a sex test.
These areas are copied 28 times and instrumental analysis used to capture and analyse the result.
This test is used to produce DNA profiles for adding to the National DNA Database (NDNAD).
This type of test is used worldwide, and a variety of commercial systems looking at different areas (markers, loci) of DNA are available.
Some samples are invisible to the naked eye, in poor condition due to external factors e.g. fire and water, or have been retained from crimes that occurred many years ago. These may have too little DNA for the standard test to be successful.

Top of page

How the Low Copy Number (LCN) technique works
The LCN test is based upon the same scientific principles as the standard SGM+
test, with variations designed to increase the sensitivity of the process, including copying the DNA sample 34 times rather than the standard 28.
The test can obtain a profile from as few as 5 - 10 cells, or from DNA that is in poor condition. This could be the amount of DNA left on a cup by drinking from it or on a pen by writing with it.
This increased sensitivity means ultra-clean laboratories are needed for the testing to minimise contamination of the sample by DNA from any other source.
Rather than performing a separate quantitation stage, a dilution stage is now included routinely to ensure that nothing else present in the sample has caused the result to be lost.

Many thanks JP for both of your posts on this.  It would have taken me hours, days or months to search this out.

Is there any indication of when SGM+ replaced SGM in the UK?  Spot 4 came up with a number of matches on NDNAD.  The analyst then cut this to 2, using additional information that could not be put into the NDNAD search.  These 2 were discounted as they were SGM standard, which I understand to be 6x2 plus sex, versus SGM+, which I understand to be 10x2 plus sex.

Now I'm guessing that apart from the totally different odds of 6x2 match v a 10x2 match, the two SGM hits must have been pretty old, with no replacement under SGM+, therefore safe to rule out, but the question is when did new entries in NDNAD switch to SGM+?

When I write up the DNA results on my blog you will be getting an honourable mention for this contribution.

And just a thought out loud.  If the NDNAD was still using SGM, would the 15 out of 19 markers have changed to 12 out of 12?  Would Portuguese courts have accepted this 'evidence', when Portugal appeared to require a higher standard?

[ShiningInLuz]

Every house is full of cellular material
Exfoliated skin is a constituent of dust

So why is it stuck up what is then a very few places of wall?  Is only a wall dusty?

And are the cleaners experts at removing it from the floor, sofa and curtains?  If so, I need to track them down and hire them, because they did one heck of a job.

They cleaned up so well after Mr Gordon bled that the dogs found not a trace.

They missed a spot on the floor that is consistent with Madeleine, and which, if the dogs are to believed, is blood, or worse.

They missed child C Gordon's ... whatever ... stuck up a wall at a height the child could not reach.

They missed the stain on the bedcover in the children's bedroom.

They appear to be both sloppy cleaners and superb cleaners.

Do you have an explanation of the spots that passes first muster?

[Mr Gray]

So why is it stuck up what is then a very few places of wall?  Is only a wall dusty?

And are the cleaners experts at removing it from the floor, sofa and curtains?  If so, I need to track them down and hire them, because they did one heck of a job.

They cleaned up so well after Mr Gordon bled that the dogs found not a trace.

They missed a spot on the floor that is consistent with Madeleine, and which, if the dogs are to believed, is blood, or worse.

They missed child C Gordon's ... whatever ... stuck up a wall at a height the child could not reach.

They missed the stain on the bedcover in the children's bedroom.

They appear to be both sloppy cleaners and superb cleaners.

Do you have an explanation of the spots that passes first muster?

as I have already said
The marks could have simply been remnants of sweaty hands
You seem to have assumed the dogs would react to all remnant human tissue
As I have explained they dont

[Alfie]

I wasn't aware that the dogs had alerted to anything on the floor that was "consistent with Madeleine"..... &%+((£

[Mr Gray]

Many thanks JP for both of your posts on this.  It would have taken me hours, days or months to search this out.

Is there any indication of when SGM+ replaced SGM in the UK?  Spot 4 came up with a number of matches on NDNAD.  The analyst then cut this to 2, using additional information that could not be put into the NDNAD search.  These 2 were discounted as they were SGM standard, which I understand to be 6x2 plus sex, versus SGM+, which I understand to be 10x2 plus sex.

Now I'm guessing that apart from the totally different odds of 6x2 match v a 10x2 match, the two SGM hits must have been pretty old, with no replacement under SGM+, therefore safe to rule out, but the question is when did new entries in NDNAD switch to SGM+?

When I write up the DNA results on my blog you will be getting an honourable mention for this contribution.

And just a thought out loud.  If the NDNAD was still using SGM, would the 15 out of 19 markers have changed to 12 out of 12?  Would Portuguese courts have accepted this 'evidence', when Portugal appeared to require a higher standard?

If the 15 out of 19 had come from the DNA one person they would have had more significance
But they didn't... They came from a soup of 3 to 5 people
This has already been explained at length
You criticise the FSS when it seems you simply do not understand the snap results
Furthermore even if the DNA had been proved to belong to Maddie it would have been of little significance

[ShiningInLuz]

as I have already said
The marks could have simply been remnants of sweaty hands
You seem to have assumed the dogs would react to all remnant human tissue
As I have explained they dont

Kindly explain how C Gordon, a child of 2 years and 3 months, got his sweaty hand approximately 1.8m or higher up the wall, at spot 9.  'Could have' does not cut the mustard.

You assert the dogs do not react to all remnant human tissue.  You haven't explained anything - you have merely asserted.  Hopefully, Keela did not alert to all remnant human tissue.  As to Eddie, when I dig him out for my blog, I will be as precise as I can about what he did and did not alert to.

For the moment, you assert, without supporting it.  And you totally ducked the point as to why this 'dust' was not all over the sofa, the curtains, covering the wall, and surely more on the floor.

You have not explained the 'blood spatter' in the slightest.

[ShiningInLuz]

I wasn't aware that the dogs had alerted to anything on the floor that was "consistent with Madeleine"..... &%+((£

Read the FSS reports.

[Alfie]

Read the FSS reports.

Would you kindly provide the specific cite?  I'm sure you're more likely to have it at your fingertips than I am.

[Mr Gray]

Kindly explain how C Gordon, a child of 2 years and 3 months, got his sweaty hand approximately 1.8m or higher up the wall, at spot 9.  'Could have' does not cut the mustard.

You assert the dogs do not react to all remnant human tissue.  You haven't explained anything - you have merely asserted.  Hopefully, Keela did not alert to all remnant human tissue.  As to Eddie, when I dig him out for my blog, I will be as precise as I can about what he did and did not alert to.

For the moment, you assert, without supporting it.  And you totally ducked the point as to why this 'dust' was not all over the sofa, the curtains, covering the wall, and surely more on the floor.

You have not explained the 'blood spatter' in the slightest.

The child was on someone's shoulders... Happens all the time

Eddie does not alert to dust which contains human skin... That would be impossible as dust is everywhere

The dust was everywhere it simply wasn't collected

As for the blood  splatter.... What are you talking about.... There was no blood splatter
You are simply digging yourself into a deeper hole

[ShiningInLuz]

If the 15 out of 19 had come from the DNA one person they would have had more significance
But they didn't... They came from a soup of 3 to 5 people
This has already been explained at length
You criticise the FSS when it seems you simply do not understand the snap results
Furthermore even if the DNA had been proved to belong to Maddie it would have been of little significance

The bit in bold I happen to find objectionable.  It is another assertion, with zero to help our guests find out how the discussion, which I am confident has taken place, actually went.  It implies an outcome with zero to support that outcome.

The snap results?  Did you mean snap results?  This is a genuine question because your predictive text seems to scramble a lot of your posts.

I think I know enough to be able to interpret the FSS results, whether interim or otherwise.  Therefore, I am confident that if I decide to criticise the FSS results, which I have not yet explained, I will be on solid ground.

You are half right in saying that if the material in a single spot had been found to be from Madeleine, and even if it had been blood, it would have been of very little significance indeed.

The problem is, the topic is not about a single spot, and whether that spot is from Madeleine, and whether that spot is blood.

It is about providing evidence as to whether "blood spatter" is a fact or a myth.

[Alfie]

The child was on someone's shoulders... Happens all the time

Eddie does not alert to dust which contains human skin... That would be impossible as dust is everywhere

The dust was everywhere it simply wasn't collected

As for the blood  splatter.... What are you talking about.... There was no blood splatter
You are simply digging yourself into a deeper hole

If Spot 9 is the spot in the picture at the beginning of this thread then I would dispute that it was 1.8 metres off the ground.  The child could have left a deposit whilst standing on a piece of furniture for example.

[Alfie]

The bit in bold I happen to find objectionable.  It is another assertion, with zero to help our guests find out how the discussion, which I am confident has taken place, actually went.  It implies an outcome with zero to support that outcome.

The snap results?  Did you mean snap results?  This is a genuine question because your predictive text seems to scramble a lot of your posts.

I think I know enough to be able to interpret the FSS results, whether interim or otherwise.  Therefore, I am confident that if I decide to criticise the FSS results, which I have not yet explained, I will be on solid ground.

You are half right in saying that if the material in a single spot had been found to be from Madeleine, and even if it had been blood, it would have been of very little significance indeed.

The problem is, the topic is not about a single spot, and whether that spot is from Madeleine, and whether that spot is blood.

It is about providing evidence as to whether "blood spatter" is a fact or a myth.

Is there anything in the FSS report that supports the view that the spots are blood spatters?  If not, then there's your answer. 

[ShiningInLuz]

The child was on someone's shoulders... Happens all the time

Eddie does not alert to dust which contains human skin... That would be impossible as dust is everywhere

The dust was everywhere it simply wasn't collected

As for the blood  splatter.... What are you talking about.... There was no blood splatter
You are simply digging yourself into a deeper hole

The child was on someone's shoulders happens to one of the better explanations I have heard for this.  The location was squeezed in against a sofa.  And the child was doing something to the wall whilst, what?

The dust was everywhere fails the photo test.  The photo has spots on the walls.

Are you ever going to explain how the sofa and the curtains seem to be basically free of this human dust?