The Detail Archives    Discuss This Issue    Subscribe to The Detail

Fingerprint News Archive       Search Past Details

G o o d   M o r n i n g !
Monday, July 12, 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

Company is Working to Reach a Wider Market with its Forensic-Quality Tools   FT. LAUDERDALE SUN SENTINEL, FL  - July 11, 2004 has become known for devices that can identify  fingerprints and handprints...

Putting Names to a Faceless Crime, 25 Years Later   SYDNEY MORNING HERALD, AUSTRALIA - July 10, 2004 digital fingerprinting technology assisted in  matching 25-year-old partial prints to two known criminals...

Innocent Man Sues After Jail NEWS24-TV, SO. AFRICA  - July 8, 2004 is suing the department of justice and the police after he had been imprisoned for 258 days because of mistaken identity...

Automated Fingerprint Matching Can be Highly Accurate WASHINGTON TECHNOLOGY, VA  - July 6, 2004 ...a study by the National Institute of Standards and Technology showed that computerized fingerprint matching can be highly accurate...

Over the weekend I did some housekeeping on the Topica subscription list.  I sent confirmation notices to subscribers not currently on "confirmed" status.  I also found some "unverified" members that I added to the list.  Both of these features insure that you sign up and want the Weekly Detail, so if you were on the list from before and no longer wish to receive the Detail, simply unsubscribe from the bottom of this page and that will be automatically taken care of.  I hope everyone continues to enjoy the Detail!


Next week we will begin accepting the first examples of some of the best non-matches.  The new "Captain Close" will be ready to receive your submissions next Monday, so be getting them ready.  We are looking for particularly good examples of close non-ID's.  The link to the new "Close Calls" page is under the "Site Features" section of the

Last week

we looked at a dialogue on point minimums, which again generated some interesting discussion on the message board.  This week we look at an article by Lisa J. Steele published just a couple of weeks ago in the Criminal Law Bulletin entitled "The Defense Challenge to Fingerprints".

The 27 page article contains over 100 references in support of the author's commentary on many current issues in the fingerprint discipline.

Mrs. Steele begins by citing 6 ways a defense attorney can attack fingerprint evidence:

1) The evidence (chain of custody, etc.)
2) The witness (training, experience, certification)
3) The science (Daubert concepts, subjectivity, confirmation bias in verification, etc.)
4) The methodology (Daubert challenge, overly-suggestive information in the case, etc.)
5) The opinion (defense expert)
6) Legitimate access (print in common location, etc.)

She continues by discussing the pros and cons of stipulating to the known exemplars and legitimate access.  The next section of the paper gives a brief history of fingerprints followed by suggestions to mount a Plaza-style challenge:

1) Fingerprinting was discovered and developed by English administrators, not scientists
2) Since its early days, fingerprint theory has been expanded but has rarely been examined by scientists outside the field.
3) Until Mitchell and Plaza, fingerprint theory was never examined by courts under Frye or Daubert.
4) Fingerprints are primarily used for criminal investigations; matching latent prints from crime scenes is different than matching fingerprints on actual fingers to exemplars
5) Fingerprinting is a technique, not a science

Next is a short section on "The Underlying Theory" that includes biology to explain uniqueness and permanence.  It is suggested to challenge other issues like the method or the identification of "smeared partial" latent prints.

"The Identification Process" is then discussed along with factors of distortion.  Mrs. Steele recommends checking for photographic documentation, digital images for altering, enhancing, or distortion, and forgery (fabrication) of evidence.  She mentions that age determination is not scientifically possible and terms like "fresh" or "recent" should be objected to.  She also mentions that there will always be "differences in detail" between two impressions and that the judge and jury should always understand that the identification is an opinion that is influenced by subconscious bias.

The next section on "Points" describes varying minimums and "ACE-V" as the replacement for point minimums.  She explains the "Ridgeology method", the three levels of detail, and to listen to make sure the examiner testifies to working from the latent to the known print.  When discussing evaluation, Mrs. Steele inadvertently used incorrect terminology to discuss distortion versus difference.  She states that "a single unexplained discrepancy between the latent print and a known exemplar is sufficient to prove conclusively that the exemplar was not the source of the latent print" but then goes on to say in the next sentence that "Discrepancies can be caused... by... pressure..., texture of the surface... and by the material used to preserve and develop the latent print."  I have made the author aware of this misstatement and she is making efforts to correct this point.

In completing the discussion of ACE-V, Mrs. Steele again mentions verification as having "inherent subjective bias" and points out to other defense attorneys that "This may be a fertile area for challenges in the future."

Under a section entitled "Error Rates" the subject of CTI (Collaborative Testing Service) rates are used to emphasize that examiners "are not infallible". 

The author spends considerable time discussing Mitchell and Plaza, and mentions Simon Cole's book as having "spawned a series of Daubert challenges to fingerprinting".  She also mentions the "1998 Richard Jackson" case in Delaware, the McKie case in Scotland, and the Cowans case in Boston. (Mayfield had not happened at the time this article was submitted)   She specifically mentions that the Joiner court "was concerned about the standards for comparison, noting that they were 'insubstantial in comparison to the elaborate and exhaustively refined standards found in many scientific and technical disciplines' and that prosecutors are advised to "elicit testimony about the expert's personal proficiency instead of relying on the field's reputation among jurors."

Focus on Plaza emphasizes it "is not a blanket endorsement of the general admissibility of fingerprint evidence", and concluded the discipline is "not a science."  Mrs. Steele cites that the Plaza court "had its greatest difficulty with fingerprint comparisons at the stage of comparison where the examiner makes a subjective judgment about the quality of the match."  Again emphasis is placed on training and certification standards of examiners, and if they do not meet or exceed the qualifications of FBI examiners in Plaza, it is recommended that they "move to exclude the examiner under Plaza as insufficiently qualified."

In an entire section devoted to "Subjective Bias" Mrs. Steele goes on to explain that "the fundamental problem in any subjective comparison with the psychological phenomena known as 'confirmation bias'" has not been considered, and that it "can play a significant role in dostorting test results regardless of the validity of the underlying theory."  She explains that confirmation bias is "a tendency to seek out and interpret evidence in ways that fit existing beliefs" and cites examples including hair comparisons and eyewitness testimony.

Mrs. Steele then gives some examples of "voir-dire questions."

Do you conduct technical procedures under clearly defined policies and procedures?
Did you follow those policies and procedures in your examination?
Do you know what a peer-reviewed journal is and why it is important?
Do you regularly read any peer-reviewed journals?  Which ones?
Are you a member of any professional organizations?  Which ones?
What qualifications are required for examiners hired by or assigned to your unit?
Do you think that newly hired examiners should have college training in science?
Can you explain "error rates" and their relevance to your testimony?
Can you explain "Confirmation bias?"
Do you know how to construct a scientifically defensible validation study?
In under a minute, can you explain the reasons for and value of validation studies?
Can you name the last two latent print validation studies your department has conducted?
Do you keep an equipment maintenance log?
Do you participate in regular, structured proficiency testing?  How did you do?
What is the minimum passing score in your department?
When you take the test, do you know it is a test?
Are the problems used in your test harder or easier than the comparisons you made in this case?
Are you certified as a Latent Print Examiner?  By whom?
Do you know what SWGFAST is and how often it meets?
Is your organization implementing SWGFAST guidelines?
What do you think of the SWGFAST guidelines?  Are they too restrictive, not restrictive enough, or about right?
Is your department using the ACE-V method?  If not, what methodology are you using and why is it superior?
Could you define ACE-V for the jury?
Can you explain ACE-V's premises and processes in about three minutes?
How many levels of ridge detail are posited in ACE-V?
What level of detail is most commonly used to effect fingerprint identifications?

A "no print defense" section outlines when to use this and when to not use this, and also when to suggest that additional development techniques might have "exposed the real bad guy".  A section on additional testing on evidence precedes the conclusion, and the paper ends with the best situations to use the "no print" defense.

The entire article is available (with permissions from the publisher) in the reference section under the Daubert subheading.

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

More formal latent print discussions are available at (


A judge has also noted "alarmingly high" error rates when fingerprint examiners took proficiency tests; in 1995 only 44 percent of 156 law enforcement examiners could correctly identify all five prints in the test, and in a 1998 study the number improved to only 58 percent."

Perceptive readers will by now see a connection between the fingerprint analysis and the identification of problematic bird species [eg waders in non-breeding plumage].

Yeah... that's what I was thinking.

Thanks to Steve Howard for this week's FFF.



Management circle will return next week



Updated the Detail Archives.


Feel free to pass The Detail along to other examiners.  This is a free newsletter 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!  (To join this free e-mail newsletter, send a blank e-mail to:  Members may unsubscribe at any time.  If you have difficulties with the sign-up process or have been inadvertently removed from the list, e-mail me personally at and I will try to work things out.

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

Have a GREAT week!