Breaking NEWz you can UzE...
compiled by Jon Stimac
Carbondale Crime Lab Receives Grant Money –
WSIL-TV, IL - Jun 8, 2007
...the Carbondale forensic crime lab is one of five labs in Illinois
benefiting from grant money...
1-hour Prints at the Pawn Shop
2007 ...working steadily, lifting palm and fingerprints
from the countertop onto a special, wide tape...
Fingerprint System Helps Nab Taunton Man –
BROCKTON ENTERPRISE, MA-
2007 ...police turned to technology to
identify a suspected drug dealer who had at least four aliases...
Ministers Face a Grilling in McKie Judicial Inquiry
- Jun 3, 2007
...inquiry into the McKie case is set to investigate claims that the
cover-up over the affair was linked to fears it would scupper the
Recent CLPEX Posting Activity
containing new posts
Moderated by Steve Everist
Not so good news out of Florida
Jessica Janisch 4291 Sun Jun 10, 2007 11:35 pm
McKie's facing court appearance?
Daktari 8111 Sun Jun 10, 2007 10:15 pm
Statistics and Misidentifications - The weeks Detail
Michele Triplett 6489 Sun Jun 10, 2007 12:37 pm
Coffey Rules on Reconsideration of Langill Decision
steve ostrowski 1085 Sun Jun 10, 2007 4:34 am
Latent Print Examiner Positions - CONUS/OCONUS
wkpetroka 455 Fri Jun 08, 2007 12:06 pm
This Will Brighten Your Day
Ann Horsman 618 Wed Jun 06, 2007 7:42 pm
Charging the defense for extra photographs and charts?
Cindy Rennie 305 Mon Jun 04, 2007 9:07 pm
WANTED - CRIMCON MK-II CAMERA(S)
CDANIELS 453 Mon Jun 04, 2007 8:07 pm
Digital Photo Logs
Steve Everist 418 Mon Jun 04, 2007 3:15 pm
Ann Horsman 914 Mon Jun 04, 2007 2:07 pm
UPDATES ON CLPEX.com
No major updates on the website this week.
We monitored an Internet
discussion on the importance of known print quality for conclusive results
from latent print comparisons.
We begin a series on latent
print reporting, process, conclusions, and error. There are many
facets to these issues, so we will proceed in a controlled manner with
specific concepts each week. This will allow time to discuss as well
as consider examples for the next week's Detail. I would like to
include as much feedback as possible, so please consider monitoring the
message forum for the related thread and posting your comments, or e-mailing
Latent Print Reporting and
by Kasey Wertheim
For years, we have heard there are only 2
conclusions in latent print examination. We have heard them in several
different forms: either it matches or it doesn't, it's ident or it's
exclusion, either the prints were made by the same source or they were not.
However, that isn't exactly what many laboratories report. We all report
identifications, or the conclusion of individualization that states that the
latent print "was made by" the same source as the known print. However, if
that conclusion is not reached, the Standard Operating Procedure of many
departments then dictates simply reporting that no identification was
The problem is that the phrase "no identification was effected" could mean
several different things. It is used by many agencies to report that the
print may have been made by that source, but the known prints were
illegible. Usually this is followed by a phrase in the report that requests
legible or clear known prints.
Another common use of th phrase “no identification was effected” is to
report that the print may have been made by that source, but the
corresponding area of the known impression was not available to the examiner
to compare (ie. when a friction ridge impression that could be either a
fingerprint or a palm print is compared against only fingerprints). Usually
this result is followed by a phrase in the report that requests additional,
complete, or fully-rolled known prints. But the real issue is whether the
fingerprint community should also use the phrase "no identification was
effected" to report the conclusion that two impressions were not made by the
same source, or an “exclusion”.
Some agencies allow their examiners to report exclusions in more clear
terms. In these agencies, standard operating procedures encourage the use of
more specific wording, such as “L-1 was not made by John Doe”. However, from
my conversations with examiners in the field, this is not the norm. It seems
that many departments still use the report phrase "no identification was
effected" to reflect opinions of exclusion. In order to address the issue of
reporting, we must critically examine the hypotheses under which our
discipline operates. Our report phraseology is a direct reflection of our
hypothesis, worded for a layperson to understand. To lay a foundation for a
discussion of latent print hypotheses, we will first touch on the concept of
errors in our discipline.
In the field of friction ridge identification, it is commonly felt that the
greatest error is to erroneously identify an individual. Fingerprint
examinations can result in the loss of life or liberty in the legal system;
therefore we set our tolerance for this type of error at the very lowest
level possible. I cannot remember a single conversation with a latent print
examiner who feels that the severity of an erroneous identification is less
than that of a missed identification. The most grievous error is generally
considered to be greater when someone is erroneously identified. In
statistics, a false positive determination is referred to as a type 1 error.
To effect a type 1 error, a scientist incorrectly claims that a result is
statistically significant when it really is not. In many disciplines, such
as fingerprints, the actions that result from a type 1 error can directly
impact life or liberty.
The lesser error is generally considered to be a missed identification, or
not 'seeing' or 'calling' a print that actually does match. It is commonly
felt that it would be better to err on the side of caution and 'let one go'
or 'not call' a print than to erroneously identify an individual. In
statistics, an error of omission is referred to as a "Type II error". In
science, a type 2 error is a missed opportunity to obtain a result that
actually existed. Since scientists think conservatively, a type 2 error is
considered much less severe than a type 1 error. In fingerprints, the result
of a type 2 error may not directly impact liberty, as would sending an
innocent person to jail with a type 1 error. However, there are obvious and
sometimes even more serious ramifications to a type 2 error in fingerprints,
such as additional actions that are allowed to occur in serial crimes
against persons or terrorism related cases.
Most examiners understand the distinction between an erroneous
identification and a missed identification, but administrators might not. If
an agency has no clear guidelines in place to deal separately with these
very different situations in latent print examination, then examiners are
left wondering what would happen if an identification is missed. In some
cases, agencies initiate punitive action for either type of error as if they
were the same. For example, an examiner may be treated as if they made an
erroneous identification for not “calling” a difficult match on a
proficiency test. Administration may view an “error” as the same regardless
of whether it was type 1 or type 2. (example of a miss on a proficiency
test) However, there are actually two different types of “missed”
identifications that in my opinion, have not been sufficiently defined and
distinguished in the past.
In casework situations where an examiner feels pressure to make a
determination on limited information, this distinction becomes obvious. In
many cases, prints that appear “close” to an examiner, but lack a sufficient
detail for individualization are correctly reported as inconclusive ("no
identification was effected"). However, I have spoken with examiners who,
when faced with this dilemma, simply threw the latent print they lifted and
were comparing in the garbage can. Rather than deal with a comparison that
was “on the edge,” they destroyed evidence. The problem is realized when it
is viewed under the parameters of a new latent print examiner… by destroying
a “close” latent print, the new examiner is basically saying that their
superiors could not identify that impression. They may be right, but is that
a decision you want a new examiner to make? The same argument would apply to
a senior examiner who has not had detailed training on the analysis,
comparison and evaluation of level 3 detail that a junior examiner has had.
How can they make a decision to eliminate the latent print from ever being
re-evaluated if they can’t recognize this type of uniqueness? After all, if
they could recognize the impression as unique and suitable, they would be
able to identify it. If a latent print appears “close” but an examiner “just
can’t quite make it”, to throw that latent print in the trash is basically
to say “nobody else could have identified it.”
There could be many reasons why an examiner might justify destroying
evidence. One might be the fear of missing an identification resulting in
peers labeling the examiner as inferior. A certain pride accompanies the
recognition of examiner expertise. Another fear might be the loss of
self-confidence that accompanies such a situation. However, I believe the
most likely root cause of destroying a borderline impression is the fear of
not being able to identify a print that someone else can match. In short, it
is in an attempt to avoid a situation that could lead to what they perceived
might have been an error, but was just a limitation of their own ability.
Most examiners are quite comfortable with their definition of sufficiency,
but they are very conservative when it comes to situations that involve any
type of error.
However, for complex latent print examinations requiring critical
discrimination ability, I feel we have not, as a discipline, necessarily
defined what action is acceptable and what is not. In fact, I don't think
the difference between types of error have even been fully resolved! I think
this lack of a clear distinction is based in part on the appearance that our
discipline appears to be defining our methodology under one set of
hypotheses, when in reality we make examination decisions by operating under
two distinctly different sets of hypotheses.
Next week, we will explore the process leading up to the examination, and
some of the associated decisions and hypothesis sets for conclusions along
the way. From there, we will look at hypothesis sets for the comparison of
two impressions followed by some additional discussion about reporting.
At the end of this series, I will combine all of the Details for a
comprehensive article, and post it on the website. But for now, some
preliminary discussion on this topic on the CLPEX.com message board would
probably be productive and lay the foundation Details in the coming weeks.
Here are some controversial views to consider for discussion:
“No Identification was Effected” is not a conclusive determination. Report
an exclusion with wording such as “the latent print XX was not made by XX”.
If a comparison isn’t quite “enough” for you, but you think it probably
matches (and wouldn’t ever fault anyone else for making the match), keep the
print in the case (don’t throw it out), and seek another examiner or outside
verification. Word your worksheet or report something like “no conclusive
determination could be made to the XX finger of XX”. And simply don’t
request additional prints. What could be more true than the truth! And if
you are ever questioned about why you weren’t sure, if you remain honest
with yourself, and what you will probably realize is that you could use some
additional training. Hey… if your agency wants more conclusive
reports, perhaps you should seek and they should provide you the opportunity
to have more conclusive training!
Here are some critical thinking questions that feed into the preceding
Do you use the phrase “no identification was effected” to report BOTH
inconclusive results as well as exclusions? If not, how do you report an
exclusion? How do you report an inconclusive result for a latent print that
should be retained as evidence in the case? Does your agency reporting
procedure prevent you from reporting an inconclusive? Or an exclusion?
If you saw similarity but not enough for you to personally make a match,
would you destroy the print? If you retained it, how would you report your
If you kept it and someone else identified it, would you be disciplined in
any way? Would you feel inadequate? Doesn’t your agency’s training play into
your lack of conclusion?
Use the Board! And enjoy the concept - this is at the heart and soul
of what we do.
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
(except in unique cases such as this week's article), and the website is open for all
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