H.W. “Rus” Ruslander, CSCSA, CLPE, CBPE, D-ABMDI
As a bloodstain pattern examiner, I have used the conventional “stringing” method I learned in the basic blood spatter course taught by Mr. Toby Wolson at the Miami-Dade Police Department. I have also used several other methods, such as mason’s chalk lines, artist tape, drawing a line through the long axis of stains with a straight edge and an overlay of the pattern area using a sheet of clear plastic with lines drawn on it with a marker.
these methods work equally well, I have found that using inexpensive
torpedo laser levels is an easy, quick and extremely accurate
method to use. These small lasers come with a tripod and, most
importantly a magnetic cap that converts the laser dot to a
straight line! They also have an off-on switch and not a momentary
switch. They can be purchased in a variety of hardware stores,
department stores or on the internet. Since they are already
threaded for 1/4x20 threads, they can be mounted onto conventional
tripods instead of using the small tripods that are included
with the laser.
used were “Torpedo Boy” by Opcom. They cost about $10.00 apiece, and are equipped with a bubble level on the top so you can make sure it is level to the floor and perpendicular to the plane of the surface where the blood stains are present.
up a number of these lasers, one can adjust the lines they project,
and then align the beams through the long axis of each blood
stain to establish a point of convergence. Photographing the
results is fairly easy by simply darkening the room somewhat
to brighten the projected light and yield photos documenting
the point of convergence with remarkable clarity. Example 1
shows an image taken from inside the residence with a Nikon
D-70 digital SLR camera of the laser beams projected onto a
white metal front door that was standing open at 90 degrees
to the door frame at about 3:00 P.M. on a bright sunny day with
ambient daylight illuminating the door. While the image is not
vibrantly bright, it is viewable. The door in this example swings
was taken with the same camera from inside the residence, of
the same door, that is now closed. No flash was used and of
course, the natural sunlight streaming in through the open door
has been eliminated by closing the door. About 4 feet away was
a window with outside light streaming through it and across
the room was another window providing natural light that illuminated
the room from behind.
Use of a flash
is not recommended when photographing the display. As with any
photography in reduced light, instead of using a flash which
would wipe out the laser beams projected on the surface, mounting
the camera on a tripod, using a shutter release cable or time
delayed trigger and extending the exposure time and/or opening
the lens will allow for more image saturation on the CCD or
image is very easy to see and use for the establishment of a
point of convergence. I have not found any drawback to using
this method in normally lit rooms. However, outside in direct
sunlight would present a problem. This could be overcome by
using tarps or some other materials to shade the area being examined.
and 4 show the laser levels that were used, one with legs extended
and one without. Example 5 shows their position on the floor
projecting up to the door.
the number of stains you use will dictate the number of lasers
you need. By using the included tripods, both with legs extended
and not, as well as conventional photographic tripods, it is
conceivable that as many as 10 or 20 lasers could be used without
too much trouble.
Once the point
of convergence has been established, it is very
easy to then determine the point
of origin by using a yard stick mounted on a tripod with either
the normal trigonometric calculations of W÷L to find the inverse sin or with the tangent method. An article by Fons Chafe (I.A.B.P.A News, September 2007, pages 4-14) in the most recent edition of the I.A.B.P.A. News details a method utilizing Excel Spreadsheets. This method teaches you how to set up an Excel spreadsheet to input the measurements that will then be calculated to show the area of origin. The only shortfall I see with this method is that it does not, by itself, graphically illustrate the point of origin like the stringing method does. The stringing method provides a good prop for photographic capture and later for display to investigators, prosecutors and judges.
method can be used to extrapolate the point of origin which
can be shown graphically on a computer using any one of a number
of drafting or crime scene diagramming programs.
By using the
lasers and then placing a yard
stick mounted on a tripod at the point of convergence, you can
then use the tangent method to determine how far away from the
surface the source that the bleeding originated from. It is
then very easy to place a marker of some sort on the yard stick
at that point to graphically illustrate the general area where
the bleeding originated from. This will preclude the need to
use actual strings but still provide the graphic image for the
to determine point of origin would be to use a laser mounted
on a protractor. Place the zero point of the protractor at the
edge and along the long axis of each stain and project it onto
the yard stick. Examples 6 through 10 show how the angle finder
laser is used and what it looks like. This will designate the
point of origin on the yard stick and where to place the Styrofoam
Bear in mind
that the actual point or area of origin would be determined
by the area(s) of impact to the actual victim. That area would
be used as the area of origin. This could require the tripod
to be lowered or raised so the area was actually on the same
plane as the area of injury the victim sustained.
12, 13 and 14 show how this was set up for example 1 and how even with bright outside light streaming into the room the laser generated lines are visible in example 1.
By using the
tripod, yardstick and a Styrofoam head that I obtained from
a wig store, the jury has a readily recognizable image of where
the event occurred, and the use of the wig display head adds
a “human” touch to the scene. Examples 15 and 16 above show how that would look when set up using the head, lasers, tripod and yard stick. These photographs were taken with just two 60 watt table lamps, illuminating the room. One lamp was about 12 feet to the right of the tripod and the other about 18 feet behind the head and tripod. Both photographs were taken with the camera being handheld, not supported by a tripod! As is evident, sharp, clear pictures are easily obtainable.
One word of
caution is needed. Research has shown that in some instances
prolonged exposure to the light emitted from lasers could have
a negative effect on DNA. I don’t think these lasers emit a strong enough beam of light to have that negative effect. However, as with any investigative process, adequate written, photographic and sample collection methods should be performed prior to any process to document point of origin or convergence.
method is much quicker than any of the other methods I have
used in the past. It took me less than 5 minutes to set up the
exercise described here. The entire amount of time it took included
the time it took to load batteries in the lasers!
article refers to the torpedo laser levels, there are other
models of lasers on the market that would lend them to this
task equally well. One model I have seen is available that can
be adjusted both vertically as well as adjusting the projected
beam at any angle between 0 and 90 degrees. These are also inexpensive
and can cost less than $10.00 as shown in example 17 and 18.
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, and administrative and investigative assignments.
he moved to south Florida where he became a civilian crime scene
investigator first for the City of Lake Worth and then for the
Palm Beach County Sheriff’s Office. He is now the Chief Investigator for the Palm Beach County, Florida Medical Examiner’s Office.
Mr. Ruslander’s accomplishments include being certified by the IAI as a Senior Crime Scene Analyst, a Certified Bloodstain Pattern group, 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 teaches for the Taylor Group, The Gold Coast Forensic Association, The I.A.I., the F.D.I.A.I, and the Tri-State Division of the IAI and has designed numerous different workshops. The Florida Department of Law Enforcement also certifies him as a law enforcement instructor.
has written over 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
is a member of the IAI, FDIAI, ABMDI, IABPA, Gold Coast Forensic
Assn. and CBDIAI, past president of the FDIAI, vice president
of the Gold Coast Forensic Association and a member of the IAI
Board of Directors.