CLPEX Chat Board

The following is a partial quotation from an Editorial titled “Changing the Culture” by William Morris the editor of Fingerprint Whorld and is in Vol. 34 No. 13 (December 2007) of that publication.

The working practice in our field of claiming that fingerprinting is infallible is one that I was taught 8 years ago and that a number of significant figures in the fingerprint community still adhere strongly to. To be honest ‘the methodology has a zero-error rate when properly applied’ is a doctrine that has always ended up with me twisting logic in circles when trying to explain it to anyone outside of fingerprints – after all, a car will never crash if it never leaves the garage. But I still used it. Better people than myself had told me it was true, I had to agree with them.

But, the success of the workshop with Dr. Dror was that this doctrine was systematically dismantled. And I realized – it’s OK to say that I’m not perfect and that I make mistakes – as long as I’m sure that I’ve done my work thoroughly, had my work checked and that there aren’t any mistakes in the case I’m presenting in the witness box. In short: I’m human, I’m not perfect – but I know this case is sound.

Like Mr. Morris this is what I was told a number of years ago and it came from people further up the food chain than I, so it must be true. I have used it in the past but now consider it (from my POV) a very weak argument. This change started a couple of years ago but was really crystallized in San Diego when listening to a panel discussion one of the LPE made the comment “you cannot separate the mind from the methodology” (forgive me if my quote is not pinpoint accurate). Wow, she was right. You take away the mind and you have what? The methodology cannot work without the human mind. It is the mind that conducts the Analysis and reaches a Conclusion. We may use an Acronym to describe the process to those who have not been trained, but they are just words that are strung together.

So where does that leave me. Not in a very good position I am afraid without a scientific study (run by scientist), which is academically approved (by PhD’s) and costs 600 million in taxpayers money and administered by government. I could use other studies that may not have approval of scientist and academia such as the one by the fingerprint critic Simon Cole which is based upon the CTS test since 1983, which he states is 0.8 percent. Or a recent one presented in San Diego which states a 0.034 percent error rate.

From my POV I do not have a problem with a stated error rate. It still falls to the individual examiner to be as accurate as they can, be as knowledgeable as they can, document their analysis or examination, have the work checked, and above all in my play book “one must know one’s limitations”.

The final statement in Mr. Morris editorial he asks the question is fingerprinting undergoing a revelation? I would like to say “I hope so.” Your thoughts and ideas?

Charles, I guess you would expect this answer from me but here goes anyway!! I have never been comfortable with he notion of a zero error rate, for either we humans or the methodlogy. You are right, the mind is the methodology, without that the method is relevent. As a result, there must be a link between the psychology associated with decision making and when mistakes do occur. I have been working these issues with Dr Dror for some years now. It has been an uncomforatble ride sometimes as getting the heirarchy to listen is often a slow and laborious process. But let us not forget that my research with Itiel Dror is only skimming the very surface of the psychological debate. It should also be noted that both Ashbaugh and P Wertheim alluded to visual illusions and daily variables respectively, so there can be no doubt that this debate has been around a long time. But do not forget that contextual bias is only a fraction of a fraction of the whole debate. There are literally hundreds of ways in which the human mind can be influenced, context is but one of them. The fact that contextual bias has raised such debate already in past few years is testament to the vast untapped reservoir of research that is needed before we can even begin to understand expert decision makgin not just fingerprints but the whole forensic and wider judicial system. Is there a revelation wthin the domain? Well, I would argue that there is movement, slow movement. The workshops Dr Dror and I give are now widely accepted in the UK as a valuable addition to the overall training of examiners. Our training schools now see such research as core to the understanding of what we do. However, while politics exists, it will still be difficult to progress as fast as I would like certainly. The UK National Fingerprint Board (US SWGFAST) wants us to move forward, as do our own training schools. But can the same be said of SWGFAST?? I respect many of the individuals on SWGFAST, but it is the politics that decrees what gets undertaken....not the scientific merit!!

I hope that 2008 is the year that academia breaks through into mainstream forensic research. I hope that 2008 will be the year when politics takes a back seat to proper scientific discussion. We shall see. Thanks Charles for raising this interesting debate and I hope this thread is the sort of thread that prevails in 2008, rather than the purile banter associated with the McKie case that s so polluting this great message board.

Happy New Year!!!


Dave

Dave, thanks for the response. The following are my personal beliefs and observations and should not be construed as coming from some higher entity. I also fully admit that these personal beliefs and observations might be incorrect and you are more than welcome to state how they are incorrect and change my point of view.

1. I sincerely appreciate the type of work that you and Dr. Dror are conducting and I think it needs to be done.

2. While the research is needed I think that the first study done with students put a bad taste in some people’s mouth. Yes, it may fit within the threshold of cognitive studies, but everyone I know in this discipline that have read that study shakes their head in a negative way. I do not think it convinced very many people of the possible problem.

3. I do agree that Bias can be a factor on some examinations but I want to know how often and under what context. When I read that Bias can affect 50% of the examinations I have to wonder where that came from. That is surely not a reasonable statement. Such statements do not lend much credence to the problem and has a negative effect on properly assessing the problem.

4. I want to know how many errors are really from Bias or from training, or from what I have read an “Information Shortcut”. I tend to believe that the vast majority is from poor training and I do like the concept of an “Information Shortcut” because I have seen it in play. The statement that if an investigator gives me the name of a subject to compare that I am automatically am biased towards that subject, from my POV is a very weak argument. Out of the all the subjects I am asked to compare for investigators, identifications are only made in about 7-8% of those requests. That means 92-93% did not match.

5. The statements that friction ridge analysis is analogous to eyewitness identification does not lend weight to concept of conceptual bias in fingerprints. From my POV apples and bananas.

6. When critics state that fingerprints should be banned because they do not have a stated error rate and have had over 100 years to develop one but have resisted is from my POV not a reasonable statement. Error rates are a fairly new concept adopted by the courts in 1991 and was not even broached with fingerprints until 1999. To say that we have been sitting on our kester for over 100 years is not an accurate statement. There are a lot of human, scientific and technical applications that do not have a stated error rate.

7. While your comments about SWGFAST may have some truth behind it, I firmly believe in the concept. I myself do not agree with everything they have done anymore than I believe everything my country has done. But I am not going to throw the baby out with the bathwater. Dave Grieve said it very well in a prior thread that getting 35 people of differing beliefs to agree on one thing is a very monumental thing and is not easy.

8. From the time fingerprints started to the time that it fully replaced Bertillionage was about 20-25 years. It did not take overnight. Your quest to speed up the process while understandable is probably not going to happen. I think it could if exceptional study or research was done that answers the questions of how many of the errors are the result of bias and how many errors actually occur. From my POV the problem of conceptual bias within the fingerprint community is overstated. Does that mean it does not exist? No! I believe there is a problem but I believe it has been overstated and enlarged upon by certain critics and defense advocates.

9. As far as errors I am concerned when I read where someone has taken Type I, Type II, and administrative errors and put them all in the same mixing pot. The standard in fingerprints has been for a long time to separate Type I , II and A-type errors. Why should that standard change. But critics want all three in the same pot because it adds to their argument. It is simply from my POV not reasonable to add Type I and II errors together to determine an error rate. But it is being done, and I questioned why that is.

10. I do not think that the studies on conceptual bias provided at this time have shown sufficient converging evidence that all errors are caused by bias and that bias is rampart within the fingerprint community.

11. If you want an easy road ahead then I suggest a good study/research on the causes of Type I errors. How often do they occur and the situations in which they occur.

12. I am not a total fan of Zero Error Rate Methodology, but I understand it came as a response to answer a recent question put forward by the courts. In my POV if something does not have a stated error rate does not make it unscientific, unsound, or bad. It just means that there is currently no way to determine accurately and reasonably what the error rate of that human endeavor is. Nothing more---Nothing less.

Again thanks, and keep doing what you are doing.

Charles, thanks for your response. If I may I will attempt to address your points sequentially.

While the research is needed I think that the first study done with students put a bad taste in some people’s mouth.

It should be noted that my research with Dr Dror is about the study of psychology and the human mind. As such, it is the academic question that needs to be answered. If we accept that we are all human, then the frailties of the mind apply to us all, expert or not. That said, as researchers we quickly established that we needed to repeat the experiments to a large extent on fingerprint experts. This was done, twice, with more subtle variables in the 2nd study using experts, but nevertheless the effects were noticed and replecated. However, ongoing study must be done, and nasty taste or not, Dr Dror and myself have gone to great lengths to offer up several sweeteners in the recent past where we have tried to engage the wider forensic community with varying degrees of success. I tend to argue that the fingerprint community needs to embrace challenge and engage academia...even the likes of Cole etc. If we find answers to critics by being full on we will gain their respect and find answers at the same time.

I do agree that Bias can be a factor on some examinations but I want to know how often and under what context. When I read that Bias can affect 50% of the examinations I have to wonder where that came from.

Good questions and ones that further research may help to answer.

I want to know how many errors are really from Bias or from training, or from what I have read an “Information Shortcut”.

Another good question. It is my assertion that bias is a factor in all our lives...because we are human beings....we cannot help it. However, I also hypothesise that training and understanding of such issues can greatly mitigate the more obvious effects. I contest the notion that applied methodology and good training can always be a major issue in offsetting contextual error...just ask the FBI in Mayfield, where the error was made by some very very experienced and highly trained officers.

The statement that if an investigator gives me the name of a subject to compare that I am automatically am biased towards that subject, from my POV is a very weak argument. Out of the all the subjects I am asked to compare for investigators, identifications are only made in about 7-8% of those requests. That means 92-93% did not match.

I see what you are saying. But here is a marker for me to lay down. Using ACE-V do we look automatically for features that match in a print and latent? Or do we look for obvious anomolies? If the former is true,at what pont do I reach that tipping point, that escalation of committment beyond which there is no going back? Even if I subsequently find anomolous features. By the way, this could be the case in negative calls too...so maybe we miss matches too!! Ths of course is only highlighted in the verification phase.....unless there is total blind verification?

e statements that friction ridge analysis is analogous to eyewitness identification does not lend weight to concept of conceptual bias in fingerprints. From my POV apples and bananas.

Bias and other psychological effects are a human trait that are generic across many disiplines. Apples and bananas re both fruit are they not ;.))

When critics state that fingerprints should be banned because they do not have a stated error rate and have had over 100 years to develop one but have resisted is from my POV not a reasonable statement. Error rates are a fairly new concept adopted by the courts in 1991 and was not even broached with fingerprints until 1999. To say that we have been sitting on our kester for over 100 years is not an accurate statement. There are a lot of human, scientific and technical applications that do not have a stated error rate.

I agree with where you base your argument. But I think it is true to say that we as a science have sat on our collective back sides for many generations on the assumption that our work was beyond reproach. We would be collectively be better placed now to offset Daubert etc etc had we engaged in long term research over many many years to look at error rate and other issues.

getting 35 people of differing beliefs to agree on one thing is a very monumental thing and is not easy

Absolutely!! There lies the problem. 35 people turn up to a meeting and group dynamics, personalities and politics conspire to a trend toward the lowest common denominator. Not easy?? It is impossible!!! What we need is for SWGFAST to stop working toward common consensus, and move toward envelope pushing ideas and research. Scientists of the world many centuries ago held the view that the earth was flat. That was the consensus. It took those with vision and bravery to counter this argument. This is what fingerprints needs now...not just in my research, but that of Glenn's, John Vanderkolk's, Christophe Champod's etc etc etc

I believe there is a problem but I believe it has been overstated and enlarged upon by certain critics and defense advocates.

Well, maybe in some cases. But maybe such people need bigger guns to break down the thick walls of dynamic inertia ;.))

Type I and II errors together to determine an error rate. But it is being done, and I questioned why that is.

I would simply ask if we assume that ACE-V is applied correctly then any technial error is valid to be put in the same category? If I miss many hits that should have been called then there is surely a chance that my lack of technical skill will result in me wrongly calling a match that sends a person to jail for life??

I do not think that the studies on conceptual bias provided at this time have shown sufficient converging evidence that all errors are caused by bias and that bias is rampart within the fingerprint community.

I couldn't agree more!! Much much more research is required and should be conducted!! But the community must be open tosuch research andacet whatever the findings may be.

I hope others will contribute to this interesting thread. I think the profession is in good hands while people like you Charles are open minded enough to look at some of these issues with an open mind.

Cheers


Dave

Okay, this discussion has awakened me from my pre-New Year coma. First, the term "anomoly" should NOT be used in reference to latent print examination. "Anomoly" means "deviation from the norm." There IS no "norm" in latent print examination. Each and every latent print is unique...one of the "commandments" of the science of fingerprints. I think the term you are seeking is discrepancy or dissimilarity. If you find an obvious discrepancy there is no "tipping point" beyond which there is no return. Of course we look for obvious discrepancies. You make it sound like we find five or six similar points and make up our minds that it is a match...reach that "tipping point'...then go on to find "anomolies" but can't change our minds back. You are not a latent print examiner if you think that goes on.

I can't deny that bias has an effect on the human mind. That is why most latent print examiners go to great lengths NOT to find out details about the cases they are working on. The details are irrelevant to the examination. I think that's where your "research" breaks down. You assume that we know every gory detail about the cases we work on and that makes our tiny minds break down. We just can't help ourselves! That's just not true. Beyond knowing the case type, (for statistical and reporting purposes), it's not my business to know who did what to who. I don't care. Whoever stated that "50% of errors are caused by bias" pulled that out of their backside.

Eyewitness identification relys ENTIRELY on the human mind...latent print examination does not. Comparing the two is not apples and bananas...it's more like apples and desk lamps.

Lumping all types of errors that can be made in the examination of latent prints together is typical junk science. There is a HUGE difference between identifying the wrong person, and identifying the right person but writing down the wrong finger. Apples and desk lamps.

My POV is that whenever someone suggests years of research they are also hoping for years of grant money. You can do all the research you want on the human mind and the effects of bias, but don't suggest that being shown a gory murder photo is going to compel me to make a mis-identification.

Intresting article at http://www.barryyeoman.com/articles/courtroom.html

Dave, thanks and you have made some good points that I would like to address. First let’s you and I keep this discussion friendly and if I step over the line (or appear to) then by all means kick me back into play. Second, on these type of discussions I believe most of the differences are actual differences in beliefs.

It should be noted that my research with Dr Dror is about the study of psychology and the human mind. As such, it is the academic question that needs to be answered. If we accept that we are all human, then the frailties of the mind apply to us all, expert or not.

(1) Yes we are all human but your statement seems to me to imply an equality of cognition, and therefore ability. Would the following statement be out of line with psychology principles to say “We are all human, and the frailties of the mind apply to all human beings but not equally”. If all of us are human, and the frailties of the mind are equally shared then where do Mozarts and Shakespeares come from. Where does that inner action come from that separates a hero from a coward. I do not believe that the same frailties of the mind come about equally among all human beings.

(2) If the question is an academic one, then the study using non-fingerprint people to show bias in fingerprints from my POV should have stayed within the academic world where its content could be truly appreciated. By submitting it to the fingerprint discipline it is my belief that it did more harm than good.

This was done, twice, with more subtle variables in the 2nd study using experts, but nevertheless the effects were noticed and replicated.

Correct me if I am wrong but Type II errors was replicated not Type I. Other than the first study Type I errors have never been made from intentional biasing study?

I tend to argue that the fingerprint community needs to embrace challenge and engage academia.

Sounds good, but which academics? Are they selected by themselves, or does the government select, and most importantly does the fingerprint community have a say in which academics are chosen? I think either way you go there will be no consensus.

It is my assertion that bias is a factor in all our lives...because we are human beings....we cannot help it. However, I also hypothesize that training and understanding of such issues can greatly mitigate the more obvious effects. I contest the notion that applied methodology and good training can always be a major issue in offsetting contextual error...just ask the FBI in Mayfield…

(1) Here we have a belief=assertion hurdle. Do we as human being have biases? Yes! Do the biases pervade our lives as much as some say they do? My current belief is no. There are over 200 catalogued biases in the cognitive sciences and they even have one for cognitive studies that are biased. If we have as many biases as some say we do, how can one even function in today’s world?
(2) In discussions such as this, Mayfield is often brought up and as well it should. It does represent itself towards such discussions whether bias was an actual issue or not. But on a different note, it is one out of 79 years of history. Now someone is going to tell me that it is the tip of the iceberg that if their is one their is another, just buried is all. It is a very nice theory, but like all conspiracy theories it does not require a shred of proof just an allegation. Yet very learned and esteemed men and women will say just that. What true scientist or academician would offer a statement without a shred of proof? My main point here is how often has it occurred, to what extent and in what context?

Using ACE-V do we look automatically for features that match in a print and latent? Or do we look for obvious anomalies? If the former is true, at what point do I reach that tipping point, that escalation of commitment beyond which there is no going back? Even if I subsequently find anomalous features. By the way, this could be the case in negative calls too...so maybe we miss matches too!! Ths of course is only highlighted in the verification phase.....unless there is total blind verification?

I look for all information for and against. It is a total assessment of all information shared and not shared between the two images. In regards to Type II errors I think that subject is broached further down. I do not believe that type I and type II errors should have the same weight. This is a human endeavor and not a mechanical one. In reference to blind verification I will submit the last issue of the Chesapeake Bay Division has an article on the topic and which I happen to agree with (mostly). I will refer you to that article on blind verification.

Bias and other psychological effects are a human trait that are generic across many disciplines. Apples and bananas re both fruit are they not ;.))

Are you saying that bias is also present in other disciplines? Yes they are. Does eyewitness identification have a propensity for biases? I would have to say yes. And they also both occur with human beings and happen on the planet Earth. That does not make them the same. Yes they are fruit and I will go you a couple better. They grow on trees, consumed by human beings, and evolved on planet earth. But they are a different shape, color, skin size, texture, taste, and you cannot cross pollinate them and get an Appanana. In conducting an experiment and you are looking at 50 issues and three are in agreement and 47 are not would you say your experiment is a success because you had 3 in agreement. I think not. 

But I think it is true to say that we as a science have sat on our collective back sides for many generations on the assumption that our work was beyond reproach. We would be collectively be better placed now to offset Daubert etc etc had we engaged in long term research over many many years to look at error rate and other issues.

As I said error rate is a new concept. If I could use a time machine and go back and warn them I would. If I could use a crystal ball to determine what new concepts will be presented in the future I would so we could prepare now. But I cannot. I can no more predict what the future issues may be 75 years from now than you or anyone else can. Should those in the future condemn us in their past for issues that are present in their world but which are unknown to us now? As more of a historian than even being close to a psychologist, it is a common complaint from historians how some in our current society talk about the past under today’s knowledge. Kind of like talking bad about the Aztecs because they did not use the wheel.

Absolutely!! There lies the problem. 35 people turn up to a meeting and group dynamics, personalities and politics conspire to a trend toward the lowest common denominator.

Is that not the same problem with Academia? Do we throw out one bunch with group dynamics, personalities and politics for a different bunch with group dynamics, personalities and politics? I do not care where you go or who you align yourself with there will always be group dynamics, personalities and politics. You would be hard put to convince me that academia/science in general have no politics or group dynamics. History would not agree with you.

What we need is for SWGFAST to stop working toward common consensus, and move toward envelope pushing ideas and research.

Here we have a belief hurdle. Their mandate is standards. To achieve those standards they need a common consensus. Ideas are like anything else human. Good ones and bad ones. If you implement a bad idea it is even harder to get rid of. Second it confuses a lot of people. I personally think we have enough bad ideas now. To set good solid standards one needs to proceed cautiously and with deep consideration.

Scientists of the world many centuries ago held the view that the earth was flat. That was the consensus. It took those with vision and bravery to counter this argument. This is what fingerprints needs now...not just in my research, but that of Glenn's, John Vanderkolk's, Christophe Champod's etc etc etc

The change of view that the earth was not flat did not happen over night it occurred over a period of time with more and more converging evidence. As stated before I have no problem with good research. I welcome and read with flavor the works of Glenn, John and Christophe.

Well, maybe in some cases. But maybe such people need bigger guns to break down the thick walls of dynamic inertia ;.))

Perhaps some people built thicker walls because they honestly believed that the rocks being thrown were false, allegations without merit, conspiracies without proof or just being thrown to fulfill a personal agenda. Would not most people or disciplines build walls if they honestly felt they were being attacked falsely? Most of the people I know are pretty reasonable. If you want them to understand something you need to show them in the best way possible not just tell them to take your word for it. I have yet to see beliefs change by throwing rocks at them. It does nothing but create a defensive posture (what some have called the fingerprint community being a closed group)

I would simply ask if we assume that ACE-V is applied correctly then any technical error is valid to be put in the same category? If I miss many hits that should have been called then there is surely a chance that my lack of technical skill will result in me wrongly calling a match that sends a person to jail for life?

(1) This is a big belief hurdle and I doubt I have the communication skills to do it justice but I am going to try. There are several ifs in your statement “if we assume ACE-V….any technical error is valid…same category?” Why must they be put in the same category? I believe they should not and my reasons are that they are not equal, they have never been equal in fingerprint analysis, being considered separately has been a standard for long time, they do not occur under the same level of consideration, they are separate because of different experience levels, different ability levels, it puts an enormous stress on young examiners to make calls they are not comfortable with. What would happen if a senior examiner says yes and a junior examiner says there is not enough for them? Do you terminate or send back for retraining. Putting type I and II errors under the same umbrella I believe would be one of the most harmful concepts. I believe in fact it would do just the very thing you are seeking to prevent—bad calls. I have often wondered why the critics would want to consider type I and type II errors together. Perhaps you could answer that---why?
(2) “If I miss many hits……lack technical skill….calling a wrong match..” (A) that is what peer review is for. If that situation is determined then you take that person off bench work for re-training or if it continues a decision to terminate. But if you have BV then there is no peer. (B) You have a big assumption there (a leap of faith is what it is called), but that is a admin and training issue. Again PR and the correct SOP and standards will correct that, not BV.

Much more research is required and should be conducted!! But the community must be open to such research and act whatever the findings may be.

I agree much more research. I agree the community must be open. However I am stuck on the last one “…act whatever the findings may be.” I would think a better discipline would want to look at the research, how it was formed, what preconceptions are in place, what bias may be present, is the research reasonable and does it follow scientific principals? You are not asking me to believe that all research that comes from academia, science, and from esteemed and learned individuals is absolutely true and correct 100% of the time. You are asking for quite a leap of faith on that one.

Dave I want to thank you. You have enlightened me with you beliefs and convictions and I hope I have not stepped over the line in my response.

For what it is worth I have always enjoyed your comments on this board and while you were editor of Fingerprint Whorld. I think you did a great job. I hope to meet you some time.

Respectfully

When I learned about error rates in college, there was always a calculable number (derived from the measuring instruments) and the standard "human error." I think this is the problem with latent prints. We have no measuring to do, so we have nowhere to calculate an error rate. If you look at error rates in other scientific disciplines, you will find that they do not address operator error. When we base everything on ACE-V, we have only operator error to address.

There is no easy way to calculate an error rate based on other factors (besides ACE-V), due to the fact that we always deal with incomplete samples. For example, DNA can calculate the error rate because they are using a complete DNA sample - they don't just get one gene or 13 alleles (sp?). Chemists deal with complete molecules - they may deal with mixtures of molecules, but not just protons and electrons. If we had the 1st joint of a finger from the core to the delta as our latent print every time, it would be easy to determine an error rate (of sorts). We could just measure the frequency of occurrence of Level 2 detail and use that to determine our error rate.

By the way, the number of bad identifications made is not the error rate. The error rate is independent of the operator. If Henry is a very good operator, then he may never make a mistake. If Oliver is a poor operator, he might make a mistake every time. It would be faulty logic, though, to say that since Henry gets it right every time and Oliver gets it wrong every time, the error rate is 50%.

I agree that research is definitely in order. That should be the constant in our universe - someone should always be questioning the way of things and looking for a better way.

Trial judges have been tasked as the gatekeepers of trial testimony. That task entails determining whether or not anticipated testimony is relevant and reliable. Our discipline has decided that we will couch our testimony as scientific. In doing so we have presented fingerprint comparison as a scientific method. Consequently, the court is concerned with deciding if the technique (our method) is scientifically valid. According to the majority opinion in the Daubert case, the error rate or potential error rate should be considered in this assessing the scientific validity of a particular technique.

The trial judge will determine whether the testimony of the witness is reliable and relevant. In a trial, the testimony of the expert fingerprint witness is to attribute the origin of a particular unknown print to a particular individual.

An ‘error' is a deviation from accuracy or correctness.

There has been much discussion about what constitutes an error in our discipline. In determining this we should (first and foremost) be concerned with the courts task of determining if proposed testimony is relevant and reliable. In the field of fingerprint comparison and identification, an erroneous identification occurs if the origin of an unknown fingerprint is attributed to a wrong individual. This is an error because the examiner is incorrect in attributing the donor of the unknown fingerprint. It is an error if the expert attributes the origin of the unknown print to the wrong individual.

The ACEV technique (method) does not have an error rate. Our technique is merely a set of steps to reach a conclusion. This is not viable testimony (see opinion of Judge Souder in the Rose decision) nor does it ring true with lay persons and some practitioners of the fingerprint discipline. The judge is trying to ascertain the reliability of our testimony by determining the scientific validity of our technique. We must view error rate from a judge’s perspective of determining if the fingerprint witness’ testimony is reliable. Obviously, the conclusion subsequent to the application of the technique/method is of utmost concern to the judge. The question becomes how often does the fingerprint expert make errors in the conclusion when applying the technique/method?

It would be difficult if not impossible for this question to be answered for the entire discipline. I opine that the rate asymptotes to zero. However, this question could be answered at a local level by the Laboratories where fingerprint comparisons are conducted and statistics kept.

There may be those among us who do not truly believe that the conclusions reached as a result of fingerprint comparisons reach the level of an immutable truth. However, in the Daubert opinion, Justice Blackmun opined that expert scientific testimony does not have to assert immutable truths: “Of course, it would be unreasonable to conclude that the subject of scientific testimony must be "known" to a certainty; arguably, there are no certainties in science . . . Indeed, scientists do not assert that they know what is immutably `true'--they are committed to searching for new, temporary theories to explain, as best they can, phenomena."#
#Justice Harry Blackmun in the majority opinion in Daubert v. Merrel Dow Pharmaceuticals

Amy, I like what you stated. I am going to steal it (if you do not mind).

Randall, I like what you wrote. I printed it out and since it is late and my cognitive skills are at a low level I will read it more closely later. But it looked pretty good at first reading.