T H E
D E T A I L
Monday, August 26, 2002
Good morning via the "Detail,"
a weekly e-mail newsletter that greets latent print examiners around the globe
every Monday morning. The purpose of the Detail is to help keep you informed of
the current state of affairs in the latent print community, to provide an avenue
to circulate original fingerprint-related articles, and to announce important
events as they happen in our field.
Last week, we reviewed the first three of ten
Daubert Concepts that we are compiling into a comprehensive
Daubert Card to be used however you see fit.
This week we take a look at the next four concepts.
As mentioned last week, the Daubert Card addresses the concepts surrounding
recent legal challenges regarding the admissibility of fingerprint evidence.
Most agree that the exact answer to each of these concepts is best prepared by
the individual examiner based on his/her training, knowledge, and experience.
Therefore, the concepts themselves and the concept response is addressed in the
Daubert Card, and word-for-word answers are not given. This also forces
each examiner to think through each issue and exactly how they would address it on the
witness stand in front of a jury. If YOU formulate your answer it will
sound better to a jury than if you used someone else's words just right but they
sounded "canned." Here is this week's continuation of the Daubert Concept
Isn't Fingerprint Examination Subjective?
Related questions might include:
Is ACE-V Subjective?
So someone else with MORE experience might arrive at a
How do you explain the results of the FBI study in the
Concept response: Fingerprint examination is mostly objective. (see
the Detail10) The only portion of the
ACE-V process that is subjective is the determination that a sufficient
quality and quantity of information exists to permit individualization, and
that determination is made based on an objective analysis and comparison of
detectable uniqueness, which is naturally affected by the knowledge,
training, skills, and experience of that examiner.
Depending on the question, you may need to clarify the difference between an
opinion of IDENTITY and an opinion of SUFFICIENCY. Your answer may
include a number of different elements, and as mentioned above, there
may be variations of the evaluation of poor quality fingerprints. But
the fact remains that two COMPETENT latent print examiners who CORRECTLY
follow the ACE-V methodology will arrive at the same conclusion of identity
or non-identity when looking at the same evidence.
The purpose of the FBI survey (Detail3)
conducted for the Mitchell trial was to demonstrate the overwhelming general
acceptance of the use of fingerprints as a means of personal identification.
All responses confirmed the acceptance that friction ridges are unique and
permanent, and that in the history of the science, there have never been two
fingerprints found to be the same.
And the fact remains after reading all of the other information about the
survey: No agency incorrectly identified either of the prints in the survey.
5) Have friction ridge arrangements been
scientifically tested and found reliable for individualization?
Other sub-concepts include:
Isn't there a lack of statistical foundation in fingerprint
This concept addresses the detail itself, not its use by a practitioner.
There has been an enormous amount of testing to support the reliability of
the use of friction ridge skin for identification purposes. Some of
the most recent mathematical research by Sharath Pankanti (IBM Research),
Salil Prabhakar and Anil Jain (Michigan State University) and many many
others before them, test the reliability of the use of level 2 friction
ridge detail arrangements for individualization through frequency studies
and AFIS research. The FBI / Lockheed-Martin 50K X 50K study
demonstrated probabilities associated with two prints containing matching
detail on level 2. (see also the Detail2)
Numerous statistical models have been proposed for over a century, and they
all support the use of fingerprints for personal identification. I am
aware of no specific statistical studies yet devoted only to level 3 detail.
See also the Detail22 for Christophe Champod's
discussion on statistical use. Collect references from YOUR study to
support these statements. We may consider adding more specific
references here later.
6) Do you know of any formal studies to
validate fingerprint matching?
Other sub-concepts include:
Doesn't the NIJ solicitation demonstrate that no validation
has been conducted in fingerprints?
Over a century of medical study of the structure and formation of
friction ridge skin has validated the fundamental principles of permanence
and uniqueness. If a sufficient quality and quantity of that detail
transfers to a surface, individualization of the source can occur.
There has been a tremendous amount of empirical validation of the use of
fingerprints for individualization. Over a century of thousands of
examiners conducting millions, probably even billions of fingerprint
comparisons around the world has not revealed two areas of skin that are
exactly the same. Further, daily AFIS use around the world since the
1980's has not uncovered two such areas of skin.
Many people were concerned with the wording of that particular NIJ
solicitation, which is why the NIJ offered clarification of their position
in a follow-up
letter: "What underlies this solicitation is the desire for more
research to further confirm the already-existing basis that permits
fingerprints to be used as a means to individualize." Scientific
methodologies and philosophies in any field are routinely examined in light
of new advances in technology in order to challenge established beliefs, and
to confirm and further validate the already-existing basis for their use.
7) Isn't it true that
there are no universally accepted standards in fingerprint examination?
Other sub-concepts include:
How do you explain differing agency minimum point
Why are training programs different?
There are many universally
accepted standards in fingerprint examination. For example, if there
is a difference in two impressions that cannot be accounted for, then the
impressions do not match. That is a standard that every examiner
trained to competency adheres to. Another standard would be ACE-V.
Although it may be described differently by some, every practitioner
examines latent impressions in a manner that conforms to this methodology.
(see also the Detail10)
Point minimums are most widely viewed as quality control measures rather
than standards. (see also the Detail51)
The standard for identification lies within what has to be present in order
for two impressions to match. This is also universal. For
example, conforming to Ashbaugh's philosophy of identification, in order for
one impression to be individualized to an impression of a known source,
there have to be ridge formations, in sequence, having sufficient uniqueness
in order to individualize (exclude every other possible source). These
four elements must be fulfilled, or else individualization can not occur.
Training programs are designed to train to competency. Although the
details of programs may differ, the end result is (hopefully) a competent
latent print examiner who conducts comparisons accurately each and every
time. The standard is training to competency.
Well, there you have the next 4 Daubert Concepts and their responses. I
have added these to our Daubert Card and linked directly to it from the home page.
Also, the message
has been quite active with some excellent discussion on law and theory, so feel free to informally chat about these
or other issues. And remember,
the Daubert Card is a living, breathing document, so if you see an area you
would like updated, please drop me a note. And as you customize your
answers, remember that addressing the Daubert issues in front of a
JURY is the road we are on right now, so think of your responses in that light.
The onin.com forum
(http://onin.com/fp/wwwbd/) is also available for more formal latent
CLPEX.com this week...
Updated the Daubert Card page.
Updated the Bookstore
to include "SOLD" on books which found new homes with examiners in attendance at
the Vegas conference. sniffle sniffle... I'll miss you guys, but I know
you will have a good home and be loved... :)
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Until next Monday morning, don't work too hard or too little.
Have a GREAT week