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Latent Print Examination » Questions from FP Experts for FP Experts... Processing, Testimony, and Technical Matters » Excluding individuals using only level 1 detail « Previous Next »

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Ernie Hamm
Posted on Friday, October 10, 2003 - 08:35 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Have you ever known or heard of a trainer that would covet a latent print of 'perfectly' superimposed loops in opposite directions to form a 'whorl' pattern? Or, for that matter, any other pattern variation intended to mislead an examiner/examiner trainee in an in-house comparison drill? Of course you have, you may be one of those sneaky instructors! Such prints were great to throw off someone JUST LOOKING AT PATTERNS!! These types of true latent prints do exist. You know they do.

As far as what you can report based on your examination; let us extend the report to the ultimate purpose, testimony. I once read something in an article, I unfortunately did not note the source, during my training. It basically expressed the following: "Do you an opinion concerning your examination?", "Yes", "Please state that opinion". At this point, you are ALONE; there are no organizations, no agencies, no colleagues, no panels, no committees, not even Mommy, guiding your words. You stand alone and they await your expert opinion.

During my working period, I did not have the luxury of time to be concerned with excluding individuals on marginal latent prints. I had enough problems making identifications/individualizations on latents of value to keep ahead of the caseload power curve. If an agency or individual would do exclusions for one case, 'they' may expect it in all cases. I can certainly see how such information could be of value in certain cases, but to make a blanket policy of claiming, reporting and comparing latents for all purposes is a little heavy. I, and many individuals reading these posts, know of cases that would still be awaiting closure.

'Nuff said, retirement is wonderful!
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Steve
Posted on Friday, October 10, 2003 - 12:59 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Kasey,

That is scary, regarding the blood print on the murder weapon.

Michele and I were just discussing the "last person to touch it" thoughts relative to exclusion. We were using the example of the push button on a transmission shifter. We wouldn't expect to identify a print from this location to the "2nd to last person to touch it". But at the same time, was the last person to touch it involved in the crime, or was it the tow truck operator putting it into neutral to make it easier to load the vehicle? Stranger things have happened!
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Kasey
Posted on Friday, October 10, 2003 - 12:45 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Steve,

I am sure the IAI has no problem with reporting an exclusion. Further, SWGFAST acknowledges this as one of three possible conclusions: Individualization, Exclusion, and Inconclusive. This is in line with ACE-V and current practices in the field. But one thing that is starting to be realized is that traditionally we have lumped exclusion and inconclusive in the same group, and simply reported "no identification was effected." I am currently drafting a paper for submission to the IAI that discusses this very issue. The big question becomes, if you know do you report it. Many are arguing the question: if you know, do you really know?

That was Dave Grieve's point at the IAI panel discussion on this topic regarding the blood print on the murder weapon in the victim's blood. The victim and husband were eliminated as having left the print. Was it the print of the boyfriend (suspect)? Surprise surprise... no. It was the print of the first EMT to arrive at the scene... he moved the weapon (and aparently had not gloved up). Scary on several levels.
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Steve
Posted on Friday, October 10, 2003 - 11:20 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Kasey,

I like the way you explained your response.

Essentially, based on your answer, a negative conclusion is being made using the same experience, skill, training, etc… that allows this examiner to make any other conclusion that they make.

I remember this coming up in the past on your site. Wasn’t there some discussion as to if the IAI allows this sort of determination to be made? Does the IAI see this as an appropriate conclusion?

I like your reference to knowing if it’s a fingerprint too… that goes beyond just being sure that the level 1 detail is correct as to pattern. I’ve seen a beautiful whorl that turned out to be on the Hallucal (ball area) of the foot.

Have you ever made this type of conclusion?
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Kasey Wertheim
Posted on Friday, October 10, 2003 - 10:50 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Scientist,

You mentioned the presence of a whorl pattern, but no mention was made of whether or not the whorl was a fingerprint, palm print, or foot print. Depending on the circumstances of the case and the location of the impression on the evidence, the way your question is phrased must acknowledge that the source of the impression could have been an area of skin other than the fingerprints represented on the card.

However, if you the examiner who determined it was a whorl also determined that it was a fingerprint, then that brings up an entirely different situation. For argument sake, let's first say that based on the skill and ability of the examiner, it is felt that there is no possibility other than the impression is 1) a whorl and 2) a fingerprint. If the submitted card has all 10 fingers and no pattern displays a whorl, then the determination of the examiner will be that the print could not have been made by the person who left the inked fingerprints. And further, I would think that examiner would be doing an injustice to simply report "no identification was effected." I believe the report should more accurately reflect the opinion of the examiner: exclusion, or "was not made by" that person.

If there is any doubt in the comparison process, absolute conclusions are not possible. This is the case with sufficient uniqueness in sequence to individualize. If the examiner has doubt, then it becomes inconclusive. The same concept applies to orientation. If the examiner is not sure where the print is from, and does not have all the known prints, then the determination is inconclusive. The injustice would be an exclusion in the midst of doubt.

However, if there is no doubt regarding orientation, then the fact remains that the examiner, based on skills, abilities, training, experience, and whatever else... has excluded the impression. He or she knows that the impression was not made by that person. And in that case, I believe the injustice is to report an inconclusive opinion when a conclusive opinion is justified.

I would argue that we should never concern ourselves about what that means. We don't claim that the presence of a print indicates guilt. We don't claim that the absence of a print indicates innocence. It shouldn't matter what an individualization or exclusion means. We are simply there to testify to the facts of the case, based on our expertise. Let the attorney's argue relevance, but I feel that facts should not be witheld just because an examiner may not feel that particular fact (exclusion) wouldn't offer relevance.

But then again, that is just my opinion based on my training and experience. :)
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Steve
Posted on Friday, October 10, 2003 - 09:48 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

This was discussed at the IAI International in Ottawa this year. It was a panel discussion that moved into several different tangents, but it was eye-opening to say the least.

Here are some thoughts that have stuck with me since the conference:

1: Who cares?
...yes, it's a sharp reply, but in the grand scheme of things does it really matter that you can say that latent #1 does not belong to this individual? How does it effect the case to have an exclusion in general, and specific to this particular print? Is the item such that you can guarantee on your career, life, etc... that the print in question must have been made by the individual that perpetrated the crime? If you can do that, did you just exclude the individual who made the card from the crime? Most likely all you did was exclude that individual as being the one who left that particular print. What does that do for this case in particular and cases in your office in general.

2: Are you sure it’s whorl?
…one of the inherent problems I’ve seen with the idea of level 1 exclusions is that of actual clarity of a print that is absent level 2 and 3. I’ve seen many prints that appeared to be one pattern type, but due to different distortions they turned out to be another. Of course this was only recognizable due to sufficient level 2 to individualize the print. I recently verified a print for another examiner. He gave me the latent and asked me to verify to a specific finger. When I first looked at the latent, I saw a double-loop whorl with smearing on the left side of the print. The finger he asked me to verify it to was a loop. I did a bit of a double take then went about verifying the individualization using the “un-smeared” portion of the print. Further analysis of the print made it clear that there was a twisting distortion on the left side of the print, which made it appear to be a double loop whorl. Thus the distortion that kept level 2 detail from existing also would have made this a false exclusion, based on level 1 only, had the rest of the print been absent the necessary detail to individualize. This also assumes that the person had no whorls, which I don't remember.

I’m not sure how your office deals with prints lacking sufficient value of individualization, but that is likely how I would evaluate/define/characterize/report this particular latent.

Or you could put in a report that the print lacks sufficient detail to individualize, but you were able to exclude “John Doe” from being the source of this print, based on level 1 detail. This is, of course, assuming your office will allow this.

But once is everything is said and done, what has this done for you? I testified once to a single print lifted from an item inside a vehicle (by an officer). It was a property damage/vandalism case. When all was said and done in court, I found out that the jury found the person guilty of the crime. Absent that one latent, I got the idea that this would have not been the case. But had I been able to exclude that print to the suspect, it wouldn’t have told anyone who committed the crime and more importantly, it would not have excluded the suspect from the crime.

Hopefully others have different ideas on the thought of level 1 exclusions.
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Scientist
Posted on Friday, October 10, 2003 - 08:22 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Please consider the following:
An agency submits evidence, which yields a single latent print. The sufficient level 1 detail present in this latent print reveals that it is a whorl. However, the scientist concludes that this whorl lacks sufficient detail to make an identification. How does/should the report read based on this conclusion?
In addition to the whorl, the agency has also submitted an inked fingerprint card for comparison. This individual does not have any whorls. Is it possible to exclude this individual based solely on level 1 detail? If so, how does/should the report read in this case?

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