VanDam Page
Updated 3-28-06
I had several responses when I announced I would be doing a Detail on the use of
PhotoShop. Excitement was the main theme, followed by various thoughts on
the use of court charts. Of course, everyone has their own opinions and
department policy regarding the use of charts in court, so I won't spend much
time on that subject. The fact is, if there were a major case at your
department and the prosecutor insisted on an in-court demonstration, you or
someone in your office would be scrambling to scrape something together in
PowerPoint or PhotoShop, etc... Unless you already know one of the
programs well, this might be a major undertaking. Of course, you could
always call me up and say, "Hey!... I heard you can chart prints in PhotoShop!"
And I would say, "Yeah, and I charge an arm and a leg!" I would rather
spend my time putting together a training course and teach you how to do it.
(which I am currently doing) But first, you have to recognize the
potential of this technique and realize how it can impact a jury.
The use of PhotoShop, a registered trademark program of Adobe Systems, Inc.,
enables a latent print examiner to demonstrate to someone else exactly what they
were looking at in a print, and sometimes even show how they were comparing the
detail itself. Through the use of color and shape (NOT lines and numbers),
an examiner can demonstrate uniqueness on all three levels. The use of
PowerPoint allows for demonstration on levels one and two, but difficulty is
encountered when trying to demonstrate ridge shape. In PhotoShop, there
are many tools other than the "Line" tool to apply color. Some of the most
frequently used tools include the paintbrush and the fill tool, used in
conjunction with a selected area. I wish I could go into detail on each
feature, but we will have to save that for class. I'll cover the basics
here.
The general concept is not that difficult to grasp. In fact, I like to
think of the use of PhotoShop in relation to already-used methods of
demonstrating to someone what you see. If you have a difficult latent
comparison (that is a match, by the way), I want you to think to yourself how
you would chart it up for a reviewer. Let's say, for example, that it is a
borderline print and you know they are going to have to really study the
identification for a while to feel comfortable with it. You would want to
show them what features you were studying, so perhaps you would prepare a
photographic enlargement and mark a few of the features in color on the
enlargement. Or maybe you wouldn't mark the photograph itself, rather you
would get a sheet of acetate and prepare an overlay with the markings.
This is exactly what PhotoShop offers. Through the use of "layers,"
markings can be created and can then be turned "On" and "Off" by showing or
hiding that particular layer, similar to flipping the acetate sheet over the
photograph and back off again. Any color application tool can then be used
to create an endless number of layers, each of which can be turned on/off in
sequence to complete the presentation.
So let's say your identification involved level 1 correspondence, a series of
unique creases, and correspondence on levels two and three. Through the
use of the selection and fill tools and the line took, level 1 correspondence
could be demonstrated. Crease correspondence could then be highlighted
using a consistent color scheme. Then, ridge by ridge, the print could be
explored by highlighting ridge path on different layers while at the same time
demonstrating other ridge shape features used during the identification process.
The result might look something like this: (but understand that you have
complete control over the timing of revealing the different layers)
This PhotoShop document was very recently used in a high profile murder trial,
and involves the print of the victim found in the residence of the suspect.
More details would be given, except that the case is still in progress.
Although this identification was broadcast on Court TV and portions of it are
already on the internet, it is presented here only for the purpose of
demonstrating this technique. When this presentation was shown in court,
even the defendant was reported to sit up attentively and stare in amazement at
the screen in the courtroom. Needless to say, the impact on the jury was
likely just as significant.
During the presentation, the file itself is opened in Adobe PhotoShop.
PowerPoint is traditionally thought of when discussing any public presentation,
but it is important to realize that the data projector is simply a method to
display what is on the screen of the laptop. In this case, PhotoShop
is started and the print is loaded on-screen. PowerPoint never comes in to
the picture. Of course, all the layers are hidden to begin with, and then
unveiled as the presenter desires. All of the traditional testimony as to
the identification process still applies, so it is beneficial for the testifying
examiner to verbally introduce the types of detail present prior to the
on-screen display of the print. In this example, creases play a major part
in the demonstration, so not only was the jury introduced to the three levels of
detail, they were also told of "occasional features," which include creases,
scars, warts, etc... Of course, as usual the testimony of the examiner in
that case is generally what juries remember. If your demeanor reflects
confidence and it is obvious to the jury that you believe in yourself and the
identification in question, then that would have just as much or more weight in
the eyes of the jury. But a nice demonstration sure couldn't hurt!
What this technique enables you to do is show the jury WHY they should be
confident about the evidence.
After the examiner presented this on-screen comparison to the court, the
following chart was introduced to demonstrate where the print had come from, and
also to give the jury something to take back to "the room." I think the
prosecution had the below image printed out in a 4X6 format. No 4 FEET by
six FEET!! Talk about an impressive color display!

Of course, a generic print could be charted to simply demonstrate the
identification process, and that could be presented in this manner in court.
Some agencies chart each identification presented in court, some chart only one,
some use a generic set of court charts, and others use no charts. From
talking with supervisors around the country (and the world,) the consensus seems
to be that the field seems to be moving toward demonstrating identifications in
court. The trend is moving away from identification "because I said so" to
a documented demonstration of the process, and possibly of the evidence in that
particular case. For that reason, these types of charting techniques using
PowerPoint or PhotoShop, should be studied by the latent print examiner and
practiced so when that case does come up, you aren't left scrambling. Or
calling me. :)~
I would also like to thank Steve Greene of the Army Crime Lab for his assistance
in helping me turn an layered Adobe PhotoShop file into a timed GIF file for
display on the internet. Now that I know this conversion process, look for
more such examples in the future!
Advanced Latent PhotoShop Training
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