T  H  E      D  E  T  A  I  L

The Detail Archives

Discuss This Issue

Subscribe to The Detail

 

Monday, August 26, 2002

BREAKING NEWz you can UzE...
by Jon Stimac


Fingerprint helps FBI Nab Suspected Reno Bank Robber - THE SAN FRANCISCO CHRONICLE - Aug. 16, 2002  ...thanks to a fingerprint, a 19-year-old woman was arrested in the attempted robbery of a bank...

Alan McNamara Released: Fingerprint 'Burglar' Vows to Clear Name -BBC NEWS - Aug. 20, 2002  ...man maintains officers mixed up prints taken from a vase he had sold in his shop...

Additional Related Links:

Jury Finds Westerfield Guilty of Murder - LOS ANGELES TIMES - Aug. 21, 2002 ...in unanimous verdict, neighbor of slain San Diego girl is also convicted of kidnapping and possessing child pornography...

Background Criminal Checks Now Required for Wall Street Employees - THE SAN FRANCISCO CHRONICLE - Aug. 22, 2002  ...measure mandates fingerprinting for certain workers, subjecting them to background security checks by the FBI...
 

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 Card:

 

4) Isn't Fingerprint Examination Subjective?

Related questions might include:
    Is ACE-V Subjective?
    So someone else with MORE experience might arrive at a different conclusion?
    How do you explain the results of the FBI study in the Mitchell trial?


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 examination?

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 testing
    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 requirements?
     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 board 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 print-related discussions.

 

UPDATES on 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...   :)
 

Feel free to pass The Detail along to other examiners.  This is a free service FOR latent print examiners, BY latent print examiners. There are no copyrights on The Detail, and the website is open for all to visit.

If you have not yet signed up to receive the Weekly Detail in YOUR e-mail inbox, go ahead and join the list now so you don't miss out!
Until next Monday morning, don't work too hard or too little.

Have a GREAT week

 

The Detail Archives

Discuss This Issue

Subscribe to The Detail