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G o o d   M o r n i n g !
Monday, May 31, 2004

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.

Breaking NEWz you can UzE...
compiled by Jon Stimac

FBI Statement on Brandon Mayfield Case   FBI.GOV  - May 24, 2004 ...Official press release from the FBI National Press Office...

FBI Apologizes to Attorney   COLUMBIA DAILY TRIBUNE, MO  - May 26, 2004 ...the FBI admitted mistakenly linking a lawyer’s fingerprint to one found near the scene of a terrorist bombing in Spain...

Spain Questioned FBI's Print Match INTERNATIONAL HERALD TRIBUNE, FRANCE  - May 27, 2004 ...Spanish authorities had raised questions about the FBI's fingerprint match weeks before the May 6 arrest...

Expert Warns Fingerprinting System is ‘Riddled with flaws’ SUNDAY HERALD, UK  - May 30, 2004 ...US forensic expert has called for a radical review of fingerprint testing to determine the extent of flawed identification…


Sorry for the missed Detail last week.

It's a "first" in almost three years.  A move from Mississippi to West Virginia was the culprit.  We still don't have phone service in our new home, but I now have a cell plan that I can use to dial out from my laptop, so I'm back online!  New contact information:

Kasey Wertheim
Director of Forensics
LumenIQ, Inc.
Subcontracted to Lockheed Martin
Software engineering section, New Projects group
Clarksburg, WV
(304) 625-5047
Cell: (304) 629-6795

From Neal Ferguson:

The San Mateo County Sheriff's Forensic Lab in California has an
opening for a Supervising Forensic Specialist.  Applications will be
accepted between May 7, 2004 and June 3, 2004.  Those interested may
apply online at or at Employee and Public Services
455 County Center, Monday thru Thursday 0700-1900 hrs. Pacific Standard


Most of you have probably seen or heard about the recent news regarding the first ever erroneous fingerprint identification reported by the FBI.  If not, read the May 25 FBI press release here. (

The most thorough media account I have seen of the case facts was published yesterday in the Oregonian, and can be found at the following link:

The basics from multiple news reports are that the FBI case examiner received a submission from Spanish authorities which consisted of a poor quality digital image of a latent print.  This image was searched on IAFIS and was identified and verified as being the fingerprint of an Oregon lawyer.  Spanish authorities developed other suspects in the case and made an identification to an Algerian National.  Within hours of the release from custody of the Oregon lawyer, the FBI issued a press release apologizing for the mistake and any harm that it may have caused.  Still unclear is whether the FBI maintains this print was erroneously identified or is of no value for identification purposes.  Also unclear is whether the impression used to identify the Algerian is the same impression compared by the FBI.

In this situation, it appears that two different people had been identified based on the same impression.  This is just as impossible as having one expert claim individualization and another claim exclusion of two impressions.  It is refreshing to see an agency admit that an error has been made and make the information public while insuring others that measures are being taken to understand what caused the mistake.  The FBI are also pursuing an active resolution to this issue by convening an independent international panel of experts to review the case and arrive at a conclusion regarding the identity or non-identity of the impressions.  This action shows the desire of the FBI to leave no questions unanswered and to bring resolution to this issue.  By taking these actions, the FBI have allowed this situation to be openly discussed in the media, by the community, and by critics of the science of fingerprints.  This discussion will lead to a healthy progression of the science of fingerprints in many ways and will provide closure to this situation within a short time period.  I believe it will also increase the desire for studies on practitioner error rate in the field of fingerprints.

Calculating Latent Print Examiner Error Rate
a commentary by Kasey Wertheim

I personally feel that the error rate of an examiner should consist only of "type 1" error, or false positives.  In latent print examination we generally think of type 1 errors when an examiner arrives at an identification decision on two impressions that were not made by the same source.  Type 2 errors, or false negatives, mostly involve impressions that were made by the same source, but the examiner arrives at an inconclusive decision (does not "make the call") when in fact they had the ability to do so.  If an examiner does not have the ability (training+experience+talent+motivation, etc.) to make the call, then the error would actually be in over-extending themselves, even though the answer happened to be correct.  Next time it might not be correct.  An accurate method does not exist that I am aware to determine an examiner's ability and therefore determine if they actually made a correct or incorrect decision. 

Traditionally, examiners who make the decision that sufficient similarity does not exist to individualize (based on their ability) have been considered to be in error.  I feel they made a correct decision based on their ability, and it should not be considered "error".  An administrative assessment may be considered, and the over-all work product of the examiner may be evaluated, but the real "error" would have been for the examiner to make the call when they were uncomfortable with that decision.  For these reasons, true "type 2" error is very difficult (if not impossible) to calculate, and therefore should not be used in a determination of latent print examiner error rate.  "Misses" (which include other scenarios in addition to both correct and incorrect "inconclusive" determinations) may be considered and used by administration as indications of potential training needs, but I don't feel they should be part of an actual "error rate" of an examiner.  In short, I believe they should be handled administratively, according to performance policy and procedure.  If you feel differently about type 1 and type 2 error, I would like to see discussion on the CLPEX message board, or feel free to e-mail me individually.  I am working on a paper for presentation at the conference in St. Louis and publication in the JFI regarding a much more detailed version of this topic, so please let me know your thoughts if you have other perspectives on this subject.

If we concentrate on type 1 error, there are several ways a practitioner error rate could be calculated.  Each method has strengths and weaknesses, and I would like to see some discussion on each of these methods.  Basically, studies can focus on casework or non-casework.  Within casework, studies could examine past, current, or future cases worked by the examiner.  Non-casework could include blind or double-blind tests, training exercises, surveys or studies, etc.  I feel that a valid study of error has to have samples that were taken under controlled, known conditions and are known to be true and accurate representations of known subjects.  If these conditions do not exist, I believe it opens up the test to scrutiny.  Any study of casework to determine error rate will always use a latent image that was not left under controlled, known circumstances. 

Ideally, an accurate study of error rate would include the examiner making decisions in as close to the same environment to casework as possible.  This is especially true if the resulting error rate will be used to make conclusions regarding the effectiveness of an examiner in casework.  The use of non-casework scenarios will always result in some condition other than casework conditions, with the exception of double-blind testing.  Double-blind tests will usually represent actual casework conditions, but a true double-blind test will only test the error rate of the lab system, not the examiner.  In other words, each identification will be double or triple checked, and non-identifications may or may not be checked, depending on laboratory policy and procedure.  Variable testing conditions among laboratories represents a potential limitation of the study, but the resulting error rate would more closely estimate the error rate of the latent print field rather than individual examiner error rate.

Images in an ideal study on error rate would be examined in a controlled environment based on standard protocols.  Proficiency testing is about as far from this ideal as possible, since the examiner knows they are taking a test.  Identifications conducted in a classroom environment might offer a good compromise between a stringent testing environment and a casework environment.  Of course in any study, false or erroneous identifications would be divided by the total number of correct identifications to arrive at the rate of error for an examiner or group of examiners.  Mean error rates of examiners or groups of examiners could then be calculated from these results.  For example, if the FBI has made ten million correct identifications in the 79 years of operation of the latent print section, then as of last week (if the Mayfield case represented an erroneous identification on the part of the FBI), their casework error rate of the FBI Lab Division would be approximately one in ten million, or .0000001 percent.

In conclusion, our profession has successfully answered approximately 50 Daubert challenges to fingerprint examination.  Also during that time, we have dealt with several high-profile problems including the McKie case, and most recently erroneous identifications in Boston and the FBI error.  These mistakes are occurring at a time when our profession is already under close scrutiny.  Examiners should continually be on guard for questions regarding errors, error rates, etc.  This issue is even brought up by Professor Starrs in today's "Riddled With Flaws" news article.  I feel that a study on practitioner error rate is overdue, and will probably be demanded in the near future.  The more we discuss what we consider to be appropriate or inappropriate about such a study, the more prepared we will be to provide the type of study that most closely represents the error rate of our profession.


To discuss this Detail, the message board is always open: (

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To inspire employees and command respect, always speak and act in the organization's best interests.  Use these tips to help you lead by example:

1. Treat everyone with respect and graciousness.  Everyone you work with - from your biggest customer to the maintenance crew - contributes to your organization's success.  Keep that in mind when greeting them in the hall, answering a question or talking with them at organizational functions.

2. Put your clients on a pedestal.  Begin staff meetings by talking about how the organization solved a problem for a client or customer.  Constantly remind staffers that their job is to serve customers, no matter what their job titles are.

3. Refer to the mission statement frequently. 
Employees look to managers to give their day-to-day work purpose and meaning.  One of the best ways to do that is to take every opportunity to remind people of the organization's mission.  When announcing a business decision, for example, use the mission to explain your decision.

3. Tie everything to goals.  Even when delivering criticism, tie your comments back to the organization's goals.  Saying "You need to redo the illustrations on the brochure to reflect our commitment to diversity" improves employees' understanding of your organization's priorities.

3. Don't complain about the organization to employees or clients.  It sets a bad example, and destroys your credibility.

Adapted from "Becoming a Leader: Communication Techniques That Motivate, Guide and Inspire Employees to Excel," via Communication Briefings, March, 2004, 800.722.9221,



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Until next Monday morning, don't work too hard or too little.

Have a GREAT week!