Let's talk about this...
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son of adam
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David Fairhurst
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RL Tavernaro
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I'll quote myself from a previous thread in responding to comments similar to John Berry's from an alleged examiner of 20 years of experience.
The use of plain impressions is common sense... how often does a natural finger touch on a surface resemble the contrived placement of a rolled fingerprint on a fingerprint card? I would think that an experienced latent print (mark) examiner would know of situations in which multiple plain impressions taken in sequence, covering all areas of pertinent friction ridge skin on that particular finger or hand, is the most practical way to get a true and accurate picture of the ridge detail present. When apparent distortions are present, multiple prints may be necessary to determine ridge detail behavior under various directional pressures. While not necessary for every comparison, this procedure should certainly be in every examiner's arsenal of tools.
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son of adam
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RLT you have this to say, "I would think that an experienced latent print (mark) examiner would know of situations in which multiple plain impressions taken in sequence, covering all areas of pertinent friction ridge skin on that particular finger or hand, is the most practical way to get a true and accurate picture of the ridge detail present."
Again, latents are chance impressions. They cannot be repeated. In addition, I have examined marks where the 'double touch' is so subtle, it is not obvious at first glance. Only comparisons allow it to become apparent that there is distortion within the impression. With that knowledge as "an experienced latent (mark) examiner" I would say that by taking plain impressions only, there is a risk that something could be missed.
RLT, do you think that you can be 100% certain that you have the most desirable prints for the job if you only have plain impressions to make that assessment on? Another aspect of taking both plain impressions and rolled impressions is that the rolled impressions can be compared with the plain impressions on the form allowing the examiner to be sure that they are working with the best prints possible.
Plain and rolled.
Again, latents are chance impressions. They cannot be repeated. In addition, I have examined marks where the 'double touch' is so subtle, it is not obvious at first glance. Only comparisons allow it to become apparent that there is distortion within the impression. With that knowledge as "an experienced latent (mark) examiner" I would say that by taking plain impressions only, there is a risk that something could be missed.
RLT, do you think that you can be 100% certain that you have the most desirable prints for the job if you only have plain impressions to make that assessment on? Another aspect of taking both plain impressions and rolled impressions is that the rolled impressions can be compared with the plain impressions on the form allowing the examiner to be sure that they are working with the best prints possible.
Plain and rolled.
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sark
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How tenable is it to choose NOT to compare the top when it needed only better elim prints and the decision to proceed was high profile and took one year. Donald Findlay QC exploited the inability of SCRO to analyse the top part at the 1999 perjury trial in cross-examination.
The Convener: It seems to me that the issue about the top part of the print is quite important. You do not seem to give the top half the same weight as the bottom part for reasons that Mr Geddes has explained. It seems obvious to me that if you felt that you did not have something to compare it with, you should have got a print form with which you were happy.
Robert Mackenzie:Deputy Head Glasgow At the time of the challenge—the extra comparisons and so on—I was satisfied, and I presume that Mr Dunbar was satisfied, that the material that we had was sufficient to eliminate. To my knowledge, we did not consider asking for another set of prints.
Alan Dunbar: We did not request that.
....................... Surely you
Col 3600
could get another McKie print.
Robert Mackenzie: What we had was limited, in that the two rolled impressions that I saw were smudged, particularly to the right-hand side, but the PLAIN impression was sufficient for me. The thought never occurred to me to ask for prints to be retaken.
Stewart Stevenson: On what basis can you say that the marks are out of sequence in the top half if you have nothing to compare them with?
Col 3601
Alan Dunbar Quality Assurance Officer Glasgow If we had taken the elim-if it had been completely rolled with no smudges on it-we may have been able to COMPLETE the comparison but we were not able to do that.
The Convener: It seems to me that the issue about the top part of the print is quite important. You do not seem to give the top half the same weight as the bottom part for reasons that Mr Geddes has explained. It seems obvious to me that if you felt that you did not have something to compare it with, you should have got a print form with which you were happy.
Robert Mackenzie:Deputy Head Glasgow At the time of the challenge—the extra comparisons and so on—I was satisfied, and I presume that Mr Dunbar was satisfied, that the material that we had was sufficient to eliminate. To my knowledge, we did not consider asking for another set of prints.
Alan Dunbar: We did not request that.
....................... Surely you
Col 3600
could get another McKie print.
Robert Mackenzie: What we had was limited, in that the two rolled impressions that I saw were smudged, particularly to the right-hand side, but the PLAIN impression was sufficient for me. The thought never occurred to me to ask for prints to be retaken.
Stewart Stevenson: On what basis can you say that the marks are out of sequence in the top half if you have nothing to compare them with?
Col 3601
Alan Dunbar Quality Assurance Officer Glasgow If we had taken the elim-if it had been completely rolled with no smudges on it-we may have been able to COMPLETE the comparison but we were not able to do that.
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Andrew Schriever
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I think some people are failing to grasp the whole picture about these plain impressions. PW obviously did not go and take one set of plain finger impressions from McKie and go on about his business.
He has stated in this thread, and before, that he took 80-100 plain impressions of McKie's left thumb. He took those impressions with the sole intent of reproducing the placement and pressure of the latent print in question.
All fingerprint examiners know that you will rarely get the exact same area of friction ridge skin twice when you are taking known prints. You may get one that is canted a little bit towards the center of the finger, the next may be a little more of the edge of the finger, the next may get more of the tip of the finger. So it is safe to assume that the sum total of all the inked prints taken represent very close to 100% of the area of the friction ridge skin which supposedly deposited the latent print.
Therefore, the arguement that a plain impression is not sufficient to record the needed area of friction ridge skin for complete comparisons is null and void. We aren't talking about A plain impression, we are talking about 80-100 plain impressions.
So to answer SofA's question for RLT:
He has stated in this thread, and before, that he took 80-100 plain impressions of McKie's left thumb. He took those impressions with the sole intent of reproducing the placement and pressure of the latent print in question.
All fingerprint examiners know that you will rarely get the exact same area of friction ridge skin twice when you are taking known prints. You may get one that is canted a little bit towards the center of the finger, the next may be a little more of the edge of the finger, the next may get more of the tip of the finger. So it is safe to assume that the sum total of all the inked prints taken represent very close to 100% of the area of the friction ridge skin which supposedly deposited the latent print.
Therefore, the arguement that a plain impression is not sufficient to record the needed area of friction ridge skin for complete comparisons is null and void. We aren't talking about A plain impression, we are talking about 80-100 plain impressions.
So to answer SofA's question for RLT:
I would say: Absolutely. If you have one finger in question, 80-100 plain impressions of that finger should prove to be FAR SUPERIOR comparison material than rolled impressions. Any competent latent print examiner who suggests otherwise has an agenda.RLT, do you think that you can be 100% certain that you have the most desirable prints for the job if you only have plain impressions to make that assessment on?
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RL Tavernaro
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SofA,
Andrew is correct & you are at least partially correct. I never suggested that rolled prints should be avoided, and actually believe that there is value in having both rolled and plain available.
As has been pointed out, it would be highly unusual (and suspicious) to have either a latent mark or an inked print exactly duplicated. Therefore the 'most desirable' inked print may be as unattainable as exactly reproducing the latent.
The point remains that one or more plain impressions may provide the best comparison exemplar for reasons previously stated, especially when a particular area of interest has been established. Stating this fact in no way discounts the value of a rolled print in certain situations, including when there is a wide horizontal area of ridge configuration to account for. In that situation, it is far more convenient to use a single exemplar rolled print (assuming both prints are of sufficient quality without excessive distortion), than having to use two or more plain impressions.
Regards, RLT
Andrew is correct & you are at least partially correct. I never suggested that rolled prints should be avoided, and actually believe that there is value in having both rolled and plain available.
As has been pointed out, it would be highly unusual (and suspicious) to have either a latent mark or an inked print exactly duplicated. Therefore the 'most desirable' inked print may be as unattainable as exactly reproducing the latent.
The point remains that one or more plain impressions may provide the best comparison exemplar for reasons previously stated, especially when a particular area of interest has been established. Stating this fact in no way discounts the value of a rolled print in certain situations, including when there is a wide horizontal area of ridge configuration to account for. In that situation, it is far more convenient to use a single exemplar rolled print (assuming both prints are of sufficient quality without excessive distortion), than having to use two or more plain impressions.
Regards, RLT
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son of adam
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I'm partially correct? To want the best set of prints to hand (rolled and plain, not plain only not rolled only) in order to carry out the most accurate comparison possible?
80 - 100 sets of plain prints - I'm sure this will be taken as another controversial attack. It's not. Taking such a large number of plains only and none rolled for comparison against a chance impression could be seen as being irresponsible.
Let's say for sake of debate that Y7 does have movement to an angle of 66 degrees which would not be apparent unless a perfectly rolled impression had been taken. If that is the case, then taking 100 plain impressions sets could turn out to be a waste of time and energy.
Plain and rolled.
80 - 100 sets of plain prints - I'm sure this will be taken as another controversial attack. It's not. Taking such a large number of plains only and none rolled for comparison against a chance impression could be seen as being irresponsible.
Let's say for sake of debate that Y7 does have movement to an angle of 66 degrees which would not be apparent unless a perfectly rolled impression had been taken. If that is the case, then taking 100 plain impressions sets could turn out to be a waste of time and energy.
Plain and rolled.
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Dick Dastardly
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The earth is flat: discuss.
I am confused, but not for the first time in all of this.
The 66 degree twist has been repeated again on this site, which originates from Mr.Swann's opinion.
I find this opinion surprising.
What images did he use (Daily Mail, internet, "originals" or otherwise) to come up with this theory? Did he use plain or rolled? When did he first think that this was the explanation? Did SCRO think this, and if so when did it first occur to them? Did McKenzie and Dunbar at Tulliallan (when they relied upon the top portion of the image) also think it had been twisted through 66? Did they say so?
Further, would it have been possible for the left thumb of McKie to have been twisted over when considering the actual position of the print on the door frame? (It was high up and slightly turned in any event, I understand)
I just cannot help wondering that if I start with the assumption that the earth is flat, I can then point to factors that support it.
Whereas if I ask myself, what shape is the earth, I can then consider the evidence and come to a conclusion.
So can the twist be replicated by Mr.Swann in the lab without causing distortion? And can he reproduce extra intervening ridges with pressure being caused as he seemed to tell the Inquiry?
I am not taking swipes. I am genuinely interested in the answers to these questions.
The 66 degree twist has been repeated again on this site, which originates from Mr.Swann's opinion.
I find this opinion surprising.
What images did he use (Daily Mail, internet, "originals" or otherwise) to come up with this theory? Did he use plain or rolled? When did he first think that this was the explanation? Did SCRO think this, and if so when did it first occur to them? Did McKenzie and Dunbar at Tulliallan (when they relied upon the top portion of the image) also think it had been twisted through 66? Did they say so?
Further, would it have been possible for the left thumb of McKie to have been twisted over when considering the actual position of the print on the door frame? (It was high up and slightly turned in any event, I understand)
I just cannot help wondering that if I start with the assumption that the earth is flat, I can then point to factors that support it.
Whereas if I ask myself, what shape is the earth, I can then consider the evidence and come to a conclusion.
So can the twist be replicated by Mr.Swann in the lab without causing distortion? And can he reproduce extra intervening ridges with pressure being caused as he seemed to tell the Inquiry?
I am not taking swipes. I am genuinely interested in the answers to these questions.
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Andrew Schriever
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RL Tavernaro
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SofA,
The partially correct comment was in reference to your apparent assumption that I was advocating the use of plain impressions only, which I was not.
In general, I have no argument with the desirability of having both rolled and plain inked fingerprints available to compare with a questioned print. I do argue, however, that to never consider using a plain impression, or worse to deny any value in using plain impressions, is demonstrably wrong. I believe you or any experienced, competent examiner should agree with that. In my personal experience there have been many occasions when both rolled and plain impressions were available, that the plain impressions presented the most accurate and reliable data for the specific comparison/identification.
Regards, RLT
The partially correct comment was in reference to your apparent assumption that I was advocating the use of plain impressions only, which I was not.
In general, I have no argument with the desirability of having both rolled and plain inked fingerprints available to compare with a questioned print. I do argue, however, that to never consider using a plain impression, or worse to deny any value in using plain impressions, is demonstrably wrong. I believe you or any experienced, competent examiner should agree with that. In my personal experience there have been many occasions when both rolled and plain impressions were available, that the plain impressions presented the most accurate and reliable data for the specific comparison/identification.
Please refer back to my earlier quote in this thread for an explanation of why multiple plain prints might be appropriate. In addition, Posted by Pat Wertheim, Thu Jun 29, 2006 4:39 pm:80 - 100 sets of plain prints - I'm sure this will be taken as another controversial attack. It's not. Taking such a large number of plains only and none rolled for comparison against a chance impression could be seen as being irresponsible.
I submit that your questions have been answered, I hope to your satisfaction. Given the available facts, I don't think we really have much disagreement on this.I took a full set of rolled impressions and plain impressions, as you would expect.
...
Why did I take so many plain impressions to work with? Several reasons. First, to duplicate as closely as possible the direction and pressure represented in the touch that produced the latent --....
Second, because I was on vacation with Dave Grieve and David Ashbaugh, I took extra inked impressions to give to them.
Regards, RLT
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son of adam
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AS, I must admit I did not see that particular post, so no, I didn't ignore it on purpose.
I still think that's an extraordinary amount of forms when it's only plains.
66 degree angled distortion. Ok we've heard it before, but it seemed like a good example as a reason for taking both plain and rolled impressions.
I still think that's an extraordinary amount of forms when it's only plains.
66 degree angled distortion. Ok we've heard it before, but it seemed like a good example as a reason for taking both plain and rolled impressions.
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RL Tavernaro
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DD,
I'll take a stab at this from memory, rather than researching it. I'm sure someone will correct me if I stray too far from the facts.
My recollection is that the 66 degree twist actually originated with John Berry. It was not clear to me if Peter Swann reached a similar conclusion independently, or just borrowed from John Berry. Mr. Swann did appear to take pains to credit John Berry for his work.
The 66 degree theory appeared to be predicated on the use of a rolled print (apparently the 'Daily Mail' print figured prominently in the development of this theory), although also taking into account at least one plain impression. A specific common ridge characteristic between the rolled and plain impressions was designated by Mr. Berry & Mr. Swann as the 'Rosetta point'.
Testimony to the Justice 1 Committee by the original SCRO (Glasgow) four seemed to indicate they had some disagreement among themselves regarding the presence of a 'twist'. If memory serves correct, Fiona McBride testified something to the effect that she had not noticed or taken into account a twist in the print, while at least two others did refer to at least the possibility of a twist. To the best of my recollection, none claimed to have originally arrived at a conclusion of 66 degrees of twist.
Regards, RLT
I'll take a stab at this from memory, rather than researching it. I'm sure someone will correct me if I stray too far from the facts.
My recollection is that the 66 degree twist actually originated with John Berry. It was not clear to me if Peter Swann reached a similar conclusion independently, or just borrowed from John Berry. Mr. Swann did appear to take pains to credit John Berry for his work.
The 66 degree theory appeared to be predicated on the use of a rolled print (apparently the 'Daily Mail' print figured prominently in the development of this theory), although also taking into account at least one plain impression. A specific common ridge characteristic between the rolled and plain impressions was designated by Mr. Berry & Mr. Swann as the 'Rosetta point'.
Testimony to the Justice 1 Committee by the original SCRO (Glasgow) four seemed to indicate they had some disagreement among themselves regarding the presence of a 'twist'. If memory serves correct, Fiona McBride testified something to the effect that she had not noticed or taken into account a twist in the print, while at least two others did refer to at least the possibility of a twist. To the best of my recollection, none claimed to have originally arrived at a conclusion of 66 degrees of twist.
Regards, RLT
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son of adam
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I note that that there appears to be an issue surrounding the matter of movement/twisting in Impression Y7 in particular the difference in opinion between the experts that identified Y7 as Shirley McKie.
May I point out that there are also differences in opinion between the 'opposing experts' in relation to movement/distortion in Impression Y7. John McLeod expressed that there was movement found in the latent. He also agreed with Peter Swann that it was a complex mark and unequivocally disagreed that it was possible to come to a conclusion in 60 - 90 seconds. Pat Wertheim stated that the mark had been placed once (and if memory serves), he did not find the mark complex at all and of course came to his conclusions in 60 - 90 seconds.
Differences of opinions are an everyday part of the job. That is why open discussion is so important. We have two sides, each side expressing the same findings but differences in how they got there.
There are holes all over this case. Seek and you will find.
Son of Adam
p.s. plain and rolled.
May I point out that there are also differences in opinion between the 'opposing experts' in relation to movement/distortion in Impression Y7. John McLeod expressed that there was movement found in the latent. He also agreed with Peter Swann that it was a complex mark and unequivocally disagreed that it was possible to come to a conclusion in 60 - 90 seconds. Pat Wertheim stated that the mark had been placed once (and if memory serves), he did not find the mark complex at all and of course came to his conclusions in 60 - 90 seconds.
Differences of opinions are an everyday part of the job. That is why open discussion is so important. We have two sides, each side expressing the same findings but differences in how they got there.
There are holes all over this case. Seek and you will find.
Son of Adam
p.s. plain and rolled.
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Dick Dastardly
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Son of Adam
Yes, it is true that there are differences of opinion in some respects. It would be astonishing if there were not. But some opinions in which there are differences are fundamental, and some are not. It may be my opinion that Wayne Rooney should not have been sent off. But the final score in the game cannot be controverted by differences in opinion.
The matter was not helped by McIntosh, the MSP, who was intent in suggesting that there were differences of opinion about matters that were not directly relevant to the issue of whether Y7 is that of McKie.
I was very interested to see from the transcript the evidence from the Durham experts: they cannot in any sense be described as "from the McKie Campaign": their evidence was not produced or fully known to the McKies until the Inquiry. Although McIntosh was at pains to try to use them to undermine other witnesses, what he failed to face up to is that they came to a view that the mark was not McKie's; and they cannot be said to be in any sense biased. That they were aware of the fact of dispute is hardly a good point, as the fact that they were being asked to consider it MUST have been because there was doubt.
It seems that most of the pro ident experts are agreed, including SCRO, that the mark is a difficult one. What I find amazing is, if it IS McKie's, she denied it immediately.
This was a high risk strategy as it might have been a fantastic latent, easily and unanimously identified by all experts. She would also have had to know that the loggist had not logged her in.....
Either she was so lucky in her foresight of the matter, and knew that there were no other prints left by her in the locus, and no witnesses to her entering the locus, and the print left by her would be so poor as to be debatable.....
OR.... it is not her print.
The former suggestion is one that she would have been looking at the same gender mixed showering, airline food, six or seven years of accommodation provided and end of a career if she was "found out". I simply cannot believe that she was that stupid, or that lucky if it is her print.
Yes, it is true that there are differences of opinion in some respects. It would be astonishing if there were not. But some opinions in which there are differences are fundamental, and some are not. It may be my opinion that Wayne Rooney should not have been sent off. But the final score in the game cannot be controverted by differences in opinion.
The matter was not helped by McIntosh, the MSP, who was intent in suggesting that there were differences of opinion about matters that were not directly relevant to the issue of whether Y7 is that of McKie.
I was very interested to see from the transcript the evidence from the Durham experts: they cannot in any sense be described as "from the McKie Campaign": their evidence was not produced or fully known to the McKies until the Inquiry. Although McIntosh was at pains to try to use them to undermine other witnesses, what he failed to face up to is that they came to a view that the mark was not McKie's; and they cannot be said to be in any sense biased. That they were aware of the fact of dispute is hardly a good point, as the fact that they were being asked to consider it MUST have been because there was doubt.
It seems that most of the pro ident experts are agreed, including SCRO, that the mark is a difficult one. What I find amazing is, if it IS McKie's, she denied it immediately.
This was a high risk strategy as it might have been a fantastic latent, easily and unanimously identified by all experts. She would also have had to know that the loggist had not logged her in.....
Either she was so lucky in her foresight of the matter, and knew that there were no other prints left by her in the locus, and no witnesses to her entering the locus, and the print left by her would be so poor as to be debatable.....
OR.... it is not her print.
The former suggestion is one that she would have been looking at the same gender mixed showering, airline food, six or seven years of accommodation provided and end of a career if she was "found out". I simply cannot believe that she was that stupid, or that lucky if it is her print.