CLPEX Chat Board

L.J.Steele wrote:Are you still getting legal challenges to uniqueness and permanence?

And why not? It's an area where it may be possible to tie a can to the tail of an examiner who has not carefully thought out responses. (Yeah. I know sophisticated defense attacks are uncommon, but we prepare by anticipating the worst.) Of the two issues, uniqueness and permanence, uniqueness is the most vulnerable. Permanence, barring trauma, is implied by what's known of skin development. It's not a total scientific lock, but an attack on permanence sounds desperate. And, of course, uniqueness is the "core value" of latent print comparison.

I think that, no matter which answer might be given to this question, aside from seeing that it is something the jury can handle (not c.), the answer has to be consistent with the other testimony about the conclusion. There is no true answer that can demonstrate proof that for some arbitrarily sized area of skin, there is no other area of skin that can make a usable impression that cannot be differentiated. Even the "good" answer, d), makes use of an unprovable statement of impossibility.

The point is not so much about absolute uniqueness but about how all that is known and has been observed about friction ridge skin makes very strong conclusions possible. When you get into this sort of questioning, I think it's important to avoid leading to an admission that uniqueness is presumed, rather than proven, and having that used in a chain of argument designed to poison the conclusion in the minds of the jurors.

My answer, which presumes I might not get to talk about the details of ridge formation in other answers:

e) From medical research, we know the ridges form while an embryo is in the womb and that they form as emerging pores line up in particular ways in response to changing pressures in the tissues. These studies suggest that there are so many variations in how this may happen in an individual that identifiable differences will always be present. This is supported by an enormous number of observations over many, many years. And because the formation of friction ridges is complete before birth, there is no known way for these formations to reform over time. This is also supported by both incidental observations and specific studies.

I stay well within what is known and make no unprovable absolute claims, and I set up the basis for a high level of confidence in my conclusion.

Disclaimer: The intent of this is to provide thought provoking discussion. No claims of accuracy exist.

Question – Analysis in court:
Will you look at this lift card and tell me what you see?

Possible Answers:

a) (Using a magnifier) I see a whorl pattern latent print that appears to have been processed with black powder.

b) (Using a magnifier) I see friction ridges that are very clear, clear enough to see the edges and pores.

c) This is a latent lift card. On one side it says it’s from case number…..and on the other side is a tape lift. I cannot analyze what’s on the tape here in court; I need the appropriate tools, lighting, and the appropriate amount of time to do an accurate analysis.

Discussion:
It’s a standard policy in some agencies to bring a magnifier to court to analyze latent or known prints. Just because this is a routine procedure doesn’t mean that this is a good procedure. This can be dangerous for a variety of reasons. Problems include using inappropriate equipment, pressures placed on the examiner, no written report or documentation of the results, no verification available, and there’s a tendency to make quick judgments instead of doing a thorough analysis. Examiners should be called to court to testify to the results of previous work completed, not called to court to do additional work on a case. In my opinion, answer c is the only good answer.

Not to hijack but sort of relevant...

Who still works regularly with paper prints and why?

Please see my thread on this on the main index

On topic... a recent move away from paper prints has caused a possible long term threat to court readiness and quality of expertise and we are looking at ways to address this.

Also, I do not see how describing the print on the card amounts to "further case work"

When you go to court you should surely know all your exhibits inside out?

I CONFESS not to have read the whole thread so excuse if my comments are not relevant...

Disclaimer: The intent of this is to provide thought provoking discussion. No claims of accuracy exist.

Question – Contemporaneous Documentation:
When did this person become a suspect?
When did you do that particular comparison?
How long did it take?

Possible Answers:
a) I’m not sure.
b) I didn’t document that information.
c) It took a while.
d) We don’t document that information because it’s not important to the identification process. Individualizations are based on the characteristics in the images, not on when information was obtained. That may be important to a different part of this case and if it is, then maybe the detective may have that information.
e) (You may be able to give this information if it’s in your case notes).

Discussion:
Contemporaneous documentation of events is important to physical examinations or tasks that can’t be redone at a later date but this isn’t needed or scientifically recommended for analytical tasks, like the identification process, that can be redone at any time.

Answers a and b: People use to recommend short answers but this view isn’t as acceptable as it use to be. If you answer the above question with a short answer then it appears that you did a less than acceptable job….that your work was lacking.

Answer c: If you don’t have the answer then it’s better to say that and indicate why you may not have the answer. Sometimes vague answers, like “it took a while”, appear unprofessional and may give the jury a poor perception of you as an expert.

Answer d: This answer is the same as a and b but it includes the reason why you didn’t do something.

Answer e: If this information is part of your case notes then you can state the answer but it may be important to mention this isn’t required information. If another expert testifies in the same case and they don’t have this type of information then you may not want it to appear that they should have included this information.

The problem with the answers suggested is that they don't put the question in context. This is likely a lead-in to one of three lines of questioning -- either a confirmation bais challenge, a tunnel vision/rush to judgment claim (possibly combined with an innocent access explanation of the print), or a fabrication theory.

If the attorney has done his/her job, then expect them to have all the relevant police reports and a pretty good timeline of who did what when -- so if the detectives had already been focusing on the defendant when the ID was made, the attorney will know that.

The detective may have already testified -- about the long hours on the case, the hard work, the sleepless nights, the long conversations with the forensic experts about the case and suspects, and so on. An examiner who answers that "I'm not sure" or "It took a while", without more -- may be an odd contrast to that detective -- this may be a place to explain a bit more about what the examiner knew when, and why that information was, or wasn't important to the review.

Expect increasing questions about what the examiner knew at the time of making the examination, during the examination process, and prior to documenting and reporting a conclusion.

Answer D risks getting you right into a Mayfield discussion about confirmation bias and the Stacey report.

If the questioner is asking "how long" questions -- then it may be part of a rush to judgment/tunnel vision claim -- that police and the lab didn't take enough time to consider alternatives and may have rushed their results.

The problem with the answers suggested is that they don't put the question in context.

From my experience, it’s common for attorneys (both prosecutors and defense attorneys) to ask questions without any context. I often wonder were they’re going with this line of questioning but in the end it seems like they had no direction.

I’ve also seen attorneys use any answer to their advantage – a short amount of time means you rushed and a long amount of time means there were difficulties with the comparison (difficulties could be a ‘Red Flag’).

One of the points of this question was that short answers use to be preferred but these days they can be used against you. Short answers may not seem bad during questioning but an attorney can imply certain things during closing arguments. In many cases, I’d recommend thorough answers over quick answers.

Another point was not to let attorneys dictate what are important issues. If an examiners knows his job well then it's their job to explain to the court what are and aren't important issues (and also be able to state why). Confirmation bias is a hot topic but it doesn't apply to every case. Examiners need to be able to state when it applies and what was done to protect against it (be able to state scientific recommendations to protect against it instead of implementing randon procedures that attorneys suggest but have no scientific support).

This is likely a lead-in to one of three lines of questioning….

From my experience, I think it’s more likely that they read this question in another transcript or off the internet and didn’t know the reason for the question.

Answer D risks getting you right into a Mayfield discussion about confirmation bias and the Stacey report.

Discussions about Mayfield and confirmation bias are bound to come up. I think it’s better for examiners to be prepared to go in this direction instead of shying away from these topics.

I try to take these sorts of questions as an opportunity to be the first to acknowledge that examinations are done with conscious attention to letting the evidence speak without influence.

"Those are all good questions, because they have to do with reliability of my conclusion and how I prevent my examinations being badly influenced."

If I did know the person was suspect, I then tell it like it was. In my case, I almost always did know they were suspect. Even if I wasn't told, it's not hard to infer that if a person was brought to my attention, there was some kind of reason. And, if not a suspect by reason of investigation, a similar argument on expectation applies to AFIS candidates.

"And I made the examination on <date>.

"I did not record the amount of time taken for the examination." (Does anyone?) "There's no time limit. It takes as long as it takes to do it right."


I've then taken the questions into the most likely context and moved a step beyond the attorney's anticipated, "So you admit you were expecting to find his prints?" My whole position is that I am an expert and that I am fully aware of the issues in my field and know how to conduct a proper analysis. It doesn't matter from this point whether the defense continues along the anticipation bias line or if the prosecutor, who hopefully I have briefed well, takes it up and uses the defense probe to emphasize that the job was done right.

Gerald,

I agree, it takes as long as it takes.

Recently it seems like many people are feeling required to note this type of information because "the courts are asking for it". I don't see a problem to do one or two things that the courts or attorneys are asking for but it seems ridiculous to do everything they ask for especially if there's not a logical reason to do it besides "they are asking for it".

I've heard this reasoning to justify contemporaneous documentation, blind verification for every case, blind verification for every ID, full documentation for every conclusion, and what information did you know at the time. If we create our procedures based on what they're asking us for (instead of what's needed) then we'll need to start documenting what target group we started with, what levels of details should you use, what was the contrast level, were you taking medication at the time, did you get enough sleep the night before the comparison, blah, blah, blah.

I don't mind documenting what's necessary but I don't like that people are thinking things are necessary only because they're being asked for in court. I would hope that instead we'd just get better at explaining why some things aren't necessary.

So because I was actually asked in court, by the defense attorney, about the fact that I was wearing glasses and about my eyes being checked and if my vision had gotten worse over time - I shouldn't have to bring documentation of my last several eye exams?

Coincidentally, I had just had my eyes examined a week earlier and for the second straight year they had actually reduced my prescription. And that was my answer - with a straight face.

The other side of wishing for more knowledgeable attorneys is that we would get more probing questions. That doesn't mean we would get only what we consider reasonable questions, just that there would be fewer dumb questions. I'm more afraid of dumb questions than tough questions. The dumb questions add an air of confusion to the proceedings. As an investigator, I'm accustomed to the same sort of questioning about every aspect of an investigation. It can be, in a way, worse than what analysts get, because there really are some practical limits to investigations. But we still followed the practice of anticipating possible defenses and exploring them during investigation.

So, I suppose the best advice for analysts would be to carry out the examination and reporting as if they would be faced with questions prepared by another, very knowledgeable examiner working for the other side. It doesn't mean one has to do everything that might be speculated on as desirable. It just means that the examiner has to be prepared to talk about them. And, although fringe questions about sleep and vision can try to set up issues, nothing beats being prepared to take a jury patiently through an examination in a way that keeps them interested and leads them to buy into the conclusion. We can take advantage of the fact that this is a field where concrete demonstration and explanation is possible in terms jurors can understand.

Disclaimer: The intent of this is to provide thought provoking discussion. No claims of accuracy exist.

Question – Blind Verification – Expected Results:
What happens if the results of blind verification are not the same as the original conclusion?

Possible Answers:
a) If the results are not the same then the individualization isn’t considered a good conclusion.

b) As long as the conclusions aren’t conflicting then there’s not a problem.

c) Conclusions may be different because of differing tolerance levels. One person may make an identification that another person is uncomfortable with due their differing tolerance levels. This is why differing conclusions isn’t a problem.

d) Our agency policy is….(state your agency policy).

e) The conclusions of blind verification are one aspect we assess but another important element to look at is how and why the blind verifier arrived at their conclusions (the justification behind the conclusion).

Discussion:
Answers a and b: If the conclusions are not conflicting (one person individualizes an image and another person says inconclusive) then no erroneous conclusion exists but the blind verification didn’t give any information about the reproducibility to the person using this tool. If a certain process is needed then it should be used in a manner that will give the user some result. When no results are given and the user isn’t concerned then they are either uneducated about the process they are using or perhaps they are not using the process as diligently as they should.

Answer c: Conclusions that differ due to tolerance levels are acceptable. This only becomes a problem when people use this as the reason that conclusions differ when there is no data to lead people to this conclusion (such as no notes that state that consistency existed but not sufficiency). If one person individualizes a latent print and another doesn’t, then we shouldn’t assume that tolerance levels were the issue unless it’s stated. Without this form of documentation, it’s just as likely that the second examiner was unable to correctly orient or locate the area of friction ridge detail that the latent print originated from. It’s also possible that the conclusions were different because different items of evidence were looked at (such as lift cards vs. photographs of lift cards).

Answer d: If your agency has a procedure then stating this it is the best answer. If an agency uses blind verification then it’s advisable to have a procedure which states when and how to use it.

Answer e: If a fingerprint comparison is so complex that blind verification is needed then justification (or documentation of the justification) should accompany the blind verification. Suppose an examiner individualized a latent print to a known print but blind verification resulted in an inconclusive determination. We can’t simple decide that the individualization should or shouldn’t be made; we need to know why this occurred. It’s possible that the two individuals were using different tools (a 4x magnifier vs. computer magnification). It’s possible that the two individuals were using different exemplars (an original vs. a livescan image vs. a copy vs. fax). It’s also possible that the two people have different visual abilities. Some people see certain shades better than others. It’s also possible that one person noticed something in the print that the other person did not. If blind verification resulted in different conclusions then we need to know the justification behind the conclusions and not make a determination about individualization prior to having this information.

I think this may be the best question of the series so far. I see the issues in latent print examination to fall into two categories. One is the fundamental nature of latent print examination, which is largely one of admissibility. The other concerns what we can usually call complex examinations, those requiring interpretations of less clear impressions and mixed impressions. And it's obviously in complex examinations that experts are more likely to conclude differently. Aside from the trivial error cases accounted for by basic carelessness and inattention, these are where we find the errors that draw such intense attention and the errors that make people wonder if they are dealing with one of those errors that hasn't been recognized. They are the ones in which someone could reasonably ask, "Could they be wrong here, too?" They are the ones that give rise to questions of how errors will be detected in cases in which a conclusion in a complex examination is not challenged by circumstances. "What if Shirley McKie had not fought?" "What if Mayfield had been in Spain at the time of the crime and the Spanish examiners had agreed with the FBI?"

The reason this question is important is that we will work our way through the fundamental admissibility challenges, once everyone gets over the novelty of fingerprint examination being challenged at all and we get down to rational admissibility testing of the kind applied and accepted in other fields. But the way we deal with complex print comparisons will affect not only the very complex, but the straightforward comparisons, also. To the lay juror, all comparisons are complex, once all the issues come into play in court. And it is because the admissibility issues will be clarified and dealt with that the challenges will move to the credibility of specific examinations.

Answer e) is the most honest and accurate. What's the follow-up likely to be? If there actually is a blind verification conclusion of Inconclusive, it seems pretty obvious that both examiners will be demonstrating their examinations. Or at least, the examiner rendering the Inconclusive will be presented with the Individualization examiner's work and asked about it. I think that would be the obvious course for an attorney to explore. That may actually be the easier circumstance to deal with.

The "what if" question may be more difficult and more common, and since more cases will feature confirming verifications, it might be asked by an attorney knowledgeable or well enough advised to recognize a complex print if it's not true that some examiners might find the comparison result to be Inconclusive. (If I really wanted to draw it out I could, of course, bring up places where the result would be Inconclusive on the basis of the lack of a high number of details.) The responses to this kind of follow-up cannot be in the abstract. That is, they cannot just be a discussion or various reasons in general why the conclusions might differ. They have to be specific demonstrations of the case at trial.

More importantly for the what I see as the future, this question bears on situations, not common now but I do believe will become more common, in which opposing hired experts will declare the result inconclusive. It is because the admissibility issues will be settled that credibility questions will become common. Verification or re-examination, it's still another examiner's conclusion. And I do not even imply dishonesty on the part of a hired gun. A simple matter of a more conservative approach can present you with this situation. I assure you that, if challenging examinations becomes routine, the conservative examiners will be known to attorneys, just as experts of particular bent are known in other fields. Once any evidence makes it through admissibility and into court, it's all a credibility contest, with the search for reasonably doubt driving it all.

In my opinion blind verification doesn't test the accuracy of the conclusion it tests examiner ability.

mgirard wrote:In my opinion blind verification doesn't test the accuracy of the conclusion it tests examiner ability.

Is this not a win / win situation then?

Maybe?, not sure what you mean, but in the end, if the blind verifier can't locate the agreement or enough agreement and calls it inconclusive what happens? I don't work for an agency that uses blind verification so I'm intrigued with how it plays out. I would hope it is not just left at a difference in opinion with neither analyst being able to explain or justify their position. Because in the end the discussion amongst peers is what allows everyone to continue to grow as examiners. And if a non-blind verification process is taking place I would hope that it too would lead to the same discussion. Like I said, from my point of view, blind verification isn't doing anything to help make sure the correct conclusion is reached. It is the open-minded discussion between well trained examiners that helps make sure the correct conclusion is reached. If you want to see which examiners need more training, then yes, blind verification is the way to go.