CLPEX Chat Board

With respect Bill I disagree with you. I don’t think myself other posters have gone off topic entirely although we may have widened it. Everything we have discussed, I suggest, is relevant to the case and of interest to it.
Surely when the details of a real case are posted on here, all things obtaining to that case are open to scrutiny and if necessary challenge.
I believe that Simon’s comments on the presentation of the Crown witness absolutely followed their disagreement in the number of characteristics i.e. 7 to 14. So that difference and why they disagree is of utmost importance to Practitioners and explains their interest.
Surely when Simon introduces that disagreement, then it follows that his opinion and the Crown Expert is open to challenge.
Bill respectfully I maintain my position and look forward to Simon either posting the image or explaining why he can’t
Kind regards
Phil

I see where you are coming from, but I was more interested in discussing the reasons for "disagreements" in the discipline, not a specific case.

I think we can all acknowledge that disagreement exists in many cases and has since the beginning of time. But unlike the seventies and eighties, we do not so easily attribute them to bad training or poor skills of the examiner.

So if we acknowledge that "identifications" or whatever we choose to call them are not all equal (easy, hard, / simple, complex, / everyone agrees, some disagree) What is the measure of an identification. What is our obligation to a jury to convey our conclusion as fairly as possible. How do you measure what a jury "hears" in our testimony

I see statistics coming into use, Can you put a number on this difficulty?

Some suggest verbal articulation of difficulty as an answer, If I can explain the conclusion better than you, does that add weight to my conclusion over yours?

I prefer the general discussion.

Bill
Thank you. I fully support your interest in discussing the reasons for disagreements in our discipline, which people outside our discipline find hard to understand.
However the subject matter in this discussion does refer to a specific case with all its issues, the most important being how two experts can be so far apart in their interpretation of the number of characteristics in agreement.
People I refer to above will read about this disagreement and say how can this be?
Regards
Phil

Philp Gilhooley wrote: ↑Wed Jul 05, 2017 10:58 am how two experts can be so far apart in their interpretation of the number of characteristics in agreement.
People I refer to above will read about this disagreement and say how can this be?

Thats easy to answer

Different standards result in different conclusions

I too think that this thread is kind of losing the original intent. As examiners, it's what we do - analyze, and in some instances, over-analyze.

The real issues here deal with sufficiency, validity and reliability, along with the ability of examiners to demonstrate their ACE processes.

Gone are the days of the old "Shane say's so" idents. In this day and age I think we should all expect to be criticized and scrutinized. We have to embrace the scrutiny because we are human and because of the consequence in what we do.

Since I have retired from public service, I too have stepped across the aisle and have done work for the defense. As a result, I see things "a little" differently than I once did.

I think we all agree that examiners are not homogeneous so we shouldn't expect consensus all the time. Particularly when the print is close to the margins of sufficiency.

One of the metrics that I think has been left alone for too long, especially in my own country; are the skills, knowledge and abilities (KSA's) of the person undertaking the ACE process commensurate or superior to the challenge within the print? Should people who have not developed the KSA's be making the tough calls? And what about the people verifying the print?
Sadly, in some cases people that do not possess the KSA's to make these calls are making these types of calls, and for a variety of reasons.
IMO Those are the cases that need the highest scrutiny.

Shane Turnidge

Bill Schade wrote: ↑Wed Jul 05, 2017 7:53 am Going back to the original post, I thought the question was along the lines of "should a witness have to demonstrate their data to a jury when giving an expert opinion".

I will probably come as no surprise to anyone that I agree with Bill.

To address some of the further comments regarding posting the images on here would mean repeating myself, therefore, I don’t intend to do so. I will, however, try to answer some of the new queries:

Les. Two good questions, thank you:

1) Yes, I did know the Fingerprint Bureau’s identification result prior to starting my comparison. The risk from this type of cognitive bias is very difficult to eliminate in this line of work. Generally, the very reason a solicitor contacts us is that his client’s fingerprint has been identified. I essentially get told that three police experts have no doubt with regards to the identification. This is quite a powerful statement and provides the risk of ‘confirmation bias’ that might influence an independent expert into agreeing with the identification result.

One of the main reasons we employ the sequential unmasking technique and linear application of ACE-V is to try and minimise any influence that we may be subjected to from both the prosecution’s identification result and the fingerprint in the reference form. Analysing a crime scene mark in isolation of the reference print essentially provides an uninfluenced record of what is observed by the examiner. This can then be referred back to after/during the comparison to allow the expert to determine to what extent they have been influenced by the reference print. Any corresponding characteristics in the mark first noticed during the comparison stage would have to be given less evidential weight than those that were originally noted during the analysis.

2) There was a further reference form provided for the defendant in this case, although this was not the ‘charge set’ used by the police Fingerprint Expert in preparation of her statement. This other reference form disclosed slightly more of the top of the print so I was able to carry out a comparison of this area. I found one further ‘clear’ corresponding ridge characteristic, two that appeared similar but were in slightly different places and one that was clear in the mark that did not appear in the print. This mixture of correspondence and differences didn’t really change my finding from inconclusive. I actually mentioned in my statement that if it was possible to obtain a fuller print from the defendant that disclosed the area just below the nail, this might provide further support to the allegation that he deposited the mark or further support for the proposition that he was not the donor.

Phil and Dr Borracho. I know the comments were intended as a criticism but I can’t help feeling extremely complimented that you think I’m an articulate master communicator with excellent presentation skills and can think quickly on my feet. Oh, and stylish too. I think they’re the nicest things anyone has ever said about me. Thank you.

Hello Simon,

Thank you for your reply, this will be my last post on this thread. Confirmation bias is an interesting subject, as is subjective observations, both of which do not help in the objective examination of latents. Integrity is a positive trait, so that no influence comes along that will sway a result apart from getting to the absolute truth of the matter. The subject of this thread has also become a challenge as to who can claim what in regard to the amount and quality of evidence present in this comparison? As I know from the McKie case experts claiming the UK gold standard 16 points identification were shown to be wrong. This could be the same in your matter, sadly we will never know the truth without actually seeing the material. You are now left with an examination result where you found more corresponding features than those that would negate the comparison. The evidential weight of one clear distinct feature against 5 that correspond plus a further two seems to raise a distinct question as to what has been observed? I will leave you in peace Simon, cheers from oz. Les

Hi Simon
As with Les Bush this will be my last posting. How can you assume that my postings were a criticism of you? You introduced this topic to the forum with details of a case you had reviewed in which you observed significantly fewer characteristics than the Crown Expert and your views on the evidence presented by both you and her. When you do so surely you expect comments to follow
I, and I am sure others will, only have wanted to view the images, out of professional curiosity. We do that because we are interested and passionate about our Science. Another reason for ending my postings is in relation to the final paragraph in your last post. I viewed that as a sarcastic reply to my postings. I may be wrong! But when somebody makes comments such as these to an experienced fellow professional then I do not wish to interact any further.
Simon, you take my postings as a compliment to your evidence presentation in the witness box. I have not reviewed any of your cases, nor have I witnessed you giving evidence so I cannot possibly give an opinion on that.
Simon whatever reasons you had for introducing this topic, some people will have had the same wish to see the impressions which were the subject of disagreement between yourself and the Crown Expert. Sadly that will not be the case and why I respectfully withdraw from this discussion.
Kind regards
Phil.