By
H.W. “Rus” Ruslander, CSCSA, CLPE, CBPE, D-ABMDI
When teaching and using inexpensive laser pointers or torpedo
lasers for trajectory analysis, I felt that there was a need to
be able to mount the lasers so that the trajectory path could
be photographed in a manner that represented the actual flight
path of the projectile.
The photography of the light
emitted by the lasers is usually
done in either reduced lighting or darkness by either fogging
the area the light passes through or, in a darkened area,
holding a piece of white paper or cardboard and slowly walking
along with the beam of light striking the paper. This is basically
a long exposure which results in the appearance of a solid
beam from the light source to the point of impact.
Some of the problems with using
the paper are, once the path
of the projectile goes above
the reach of an average person,
it is very difficult to continue
showing the path using this
method. Another problem encountered
is trying to keep the laser’s
beam on the paper. An issue with
the fogging method, especially
when outdoors, is that the
fog dissipates rather quickly
if there is a breeze. In an indoor scene, the fogging works
well but the author has set off smoke detectors
using it.
Another consideration is any
health issues of the participants.
Some people may be allergic to
the chemicals used or experience
an asthma-like reaction.
Generally, when doing a reconstruction
using the lasers, the area is
first photographed completely
using proper lighting and photographic
techniques from all angles. Then, the lasers are set up and
the area is photographed again to show the placement of the
devices.
The next step is to fog the area.
Once the fog has reached a level
to allow laser beams to become
visible, they are photographed.
Cameras are tripod mounted, the
auto focus turned off as well
as the flash, and the camera
focus is set on infinity. The
area to be photographed is framed
and if possible, a remote shutter
release device is used. If a remote release device is not
available, you can simply set the camera on a timed exposure
setting, depress the shutter release and remove your hand.
This will usually allow the camera to stop any shaking that
touching it may have caused. The camera is set on either bulb
or shutter priority and the ASA set at 1600 or as high as
your camera will allow. The lights are now turned off and
the scene is photographed as it appears once the lasers are
turned on.
Photographs are generally taken
from at least 3 different angles.
One from the point of view of
the shooter, one from the point
of impact and one from either
or both sides perpendicular to
the beam of light. Next, a low
level of light is turned on and the scene re-photographed.
This will allow the recording of the background, and impact
areas. This is very similar to photographing a luminal scene
where a short burst of light is used at the end of the exposure
to show the surface the reaction is on without washing out
the luminal reaction itself.
In order to get a better photograph
showing a view taken from the
actual level of the laser beam,
I decided to make a bracket that
would mount onto the camera or
tripod and hold the laser(s).
I purchased a 3’ piece of aluminum that is bent at a 90
degree angle and each side was 1” wide and cut it into
3 pieces, each 1’ long. I drilled a hole in the center of
one side of the bracket. I also
purchased a thumbscrew with 1/4x20
threads and threaded base that
would slip over the bracket (figure
1).

Figure 1
In addition, I also purchased
a pack of Velcro tabs to use
to secure the laser pointers
to the piece of metal (figure
2, 3 and 4).

Figure 2

Figure 3

Figure 4
Using
a bracket that is designed
to mount a flash off to the
side of a camera, I mounted
the bracket and camera on the
tripod. I adjusted the bracket so the lasers were along the
same plane as the lens (figure 5 & 6).

Figure 5

Figure 6
The laser pointers are activated
by depressing the momentary switch
by using a spring paperclip.
With the area fogged, a photograph
can now be taken that represents
the sight path the shooter saw
when he/she aimed the weapon
at the target. The camera can
then either be repositioned and
a photograph taken for the viewpoint
of the point of impact or, simply
rotated 180 degrees and a photograph
taken to show where the shooter
had been when the shot was fired.
By positioning the camera along the flight path and using 2 laser
pointers, one facing in each direction, photographs can be taken
showing both the point of impact and the area the shot was fired
from (figure 7).

Figure 7
By introducing a second laser
pointer, it can be demonstrated
how 2 combatants were firing
at each other. A green laser
can be used so there is no question
who was firing which shot. The
victim and suspect would each
be given a different color (figure
8).

Figure 8
The total outlay for the 2 laser
pointers and the hardware was
approximately $36.00. The green
laser pointers are now available
on the internet, imported from
Asia for about $15.00 each and
the aluminum bracket and thumbscrew
from the local hardware store
for a total of less than $5.00.
The spring clip used to hold
sheets of paper together are
easily obtained from your local
office supply store and come
in a variety of colors too. The camera bracket for positioning
the flash off camera is available from most camera stores
and costs between $16.00 and $60.00 depending on the type
you select. I already had one so no additional cost was involved.
About the author:
Harold W. “Rus” Ruslander spent the first 23 years
of his career as a Prince George’s County, Maryland Police
Officer. That career included
uniform patrol, special operations,
administrative and investigative
assignments.
After retiring, he moved to south Florida where he became
a civilian crime scene investigator, first for the City of Lake
Worth in March of 1993, and then for the Palm Beach County Sheriff’s
Office from December 1996 until January 2003. He has been the
Chief Investigator for the Palm Beach County, Florida Medical
Examiner’s Office since January, 2003.
Mr. Ruslander’s’ accomplishments
include being certified by
the IAI as a Senior Crime
Scene Analyst, a Certified
Bloodstain Pattern Examiner
and a Certified Latent Print Examiner as well as by the ABMDI
as a Registered Medicolegal Death Investigator. In addition,
he is Court recognized as a bloodstain pattern, latent fingerprint
and crime scene reconstruction expert.
Mr. Ruslander has taught forensics at many locations throughout
the United States and has designed numerous forty-hour classes
and workshops. The Florida Department of Law Enforcement also
certifies him as a law enforcement instructor.
Mr. Ruslander has written in
excess of 20 forensic articles,
which have been published in
a number of forensic publications
and various sites on the
worldwide web. Mr. Ruslander
has also made presentations
and taught courses for the
IAI Annual Training Conferences, the FDIAI Annual Training
Conferences, The East Coast Armed Robbery Association, The
Taylor Group, The Gold Coast Forensic Association, the Florida
Chaplains Association and the Florida Fire Marshals Association,
to name a few.
Mr. Ruslander is a member of the IAI, the FDIAI, the CBDIAI,
FOP 89, FAME, ABMDI, IABPA, The American Legion, The Gold Coast
Forensic Association and EPIC. |