Getting a Handle on Processing Vehicles
Written by Detective Donald J. Frost II   

THE PROCESSING OF VEHICLES for evidence is a familiar part of the job for crime scene detectives, as well as specially trained detectives, officers, deputies and troopers. It is usually a straightforward process that at times becomes perfunctory. The most basic procedure is to visualize and photograph the vehicle, examine the vehicle exterior and interior, photograph again as needed, collect items of interest for evidence or for additional processing, obtain specimens when applicable, and finally, process for latent prints (usually accomplished by standard dusting techniques). Each of these steps is accomplished in a specified order consistent with any other type of search patterns.


Using an inexpensive mirror, a camera, and basic latent-print development techniques, latent prints can be recovered from the backs of door handles. These lifts are examples of latents recovered by the author from the backs of door handles in actual cases.

The actual component of processing for latent prints is no different; it is typically a systematic process, focusing on places on and in the vehicle where someone may have touched the vehicle through normal interaction, or other interaction articulated by the fact pattern of the case. These basic areas typically include the roofline above the doors, the exterior and interior of the doors and windows, dashboard, console, rear-view and vanity mirrors, and shift knob.

One area that is often overlooked because of difficult accessibility and because of its relatively small surface area is the back of the interior door handle. While textured door handles will likely yield no viable print impression evidence, the smooth door handles that appear “chromed” on many makes and models of vehicles have the potential to yield excellent latent print evidence. It is somewhat difficult and unconventional to attempt to access the side of the door handle, especially with cars that have the smaller handles recessed into the door and the fact many only swing out to around 45° or so. While these areas aren’t readily accessible, processing them is not impossible. In fact, with the right tools and a little practice, it is very possible to successfully process this area. Under the right circumstances, latent print impressions of excellent quality can be successfully developed, visualized, and ultimately recovered from the back side of a door handle.

The principles and variables that govern this processing are the same as those that govern latent print processing on any other substrate—including the amount of secretion of the print donor, the cleanliness of the door handle, as well as its texture and porosity. In some instances, latent prints on the backs of door handles can actually be photographed prior to recovery. As in any other instance of latent print processing, photography prior to recovery is extremely desirable. This is because, as in any other instance of latent print processing, latents may be only partially recovered, damaged, or even completely lost during the recovery process. The possibility of any of these losses is increased in this particular situation due to the fact that the recovery location is already difficult to access.

Processing

To visualize any possible latent print evidence in this area, the use of a simple small inspection mirror (typically available at your local automotive parts store for a couple of dollars), along with an external adjustable light source such as a flashlight, can allow visualization and even photography of latent print evidence prior to recovery. In many cases the inspection mirror will fit behind the handle, and by adjusting the angle of the mirror head and the angle of the light striking the mirror from the flashlight, the back of the handle will be clearly illuminated and visualized in the mirror.

The real challenge is how to utilize all of the components simultaneously to capture the desired image. When working alone, we only have two hands, and when you throw in a camera in addition to the mirror and flashlight, we are theoretically looking at handling at least three items while attempting to photograph the print… or four items if you decide to try to include a scale, which is consistent with best practices, but not always practical in this situation.

This processing procedure is actually surprisingly simple. You first visualize the back of the door handle prior to any processing using the flashlight and mirror. Sometimes the “latent” print is actually fairly visible prior to enhancement with the fingerprint powder and it may be beneficial to photograph the print “as-is” prior to dusting. Next, you will want to process via dusting—probably with oxide powder. It may technically be feasible to dust with magnetic powder, but the recessed area of the door where the handle rests, the typical concave nature of the back of the door handle, and the close proximity of metal screws may render this method much more difficult, though not impossible. The twirling action of a standard nylon bristle brush works well to maximize the surface area of the concave back of the door handle that will come into physical contact with the processing powder. You will need to hold the door handle out away from the door as far as it will swing during this step to facilitate room for the brush. The trick is to hold the handle in the open position without disturbing the latent print evidence. This can be accomplished by holding the upper and lower edges of the door handle or the tip of the handle. Upon completion of the dusting, repeat the visualization process. If you have latents of sufficient quality, it is time to photograph!

Photography

Placing the camera on a tripod is the most advantageous method of photography. Depending on the door configuration, you may be able to secure the inspection mirror to the door itself using simple lift tape. Position the mirror head behind the handle and secure the mirror handle to the door in a manner that provides the correct reflection angle for photography. This will leave your hands free to operate the light and camera. Once you have the mirror positioned and secured, simply illuminate the latent via the mirror, set up the camera, and take your photographs. If you are unable to secure the mirror with tape due to a particular door configuration, you can also set up the camera ahead of time and utilize the camera’s timer to free up your hands for holding the mirror and light.

Photographs of these latents will need to be corrected prior to any AFIS entry. With this method, the light tends to illuminate the powder in such a fashion that the ridges and valleys of the print appear to be interchanged (essentially a photographic negative of the true print). Simple digital editing software can easily correct the issue, or the AFIS system can accomplish the same thing. Also, the whole pattern itself is reversed, as it is visualized and photographed in a mirror. The same editing software or AFIS workstation can reverse the whole image as well. Once these visual corrections are made, the image essentially becomes the equivalent a standard latent lift in ridge coloring and pattern orientation.

The final correction required is usually accomplished at the AFIS workstation. As stated before, the use of a scale is extremely difficult, if not impossible. But in a case where it is simply not practical to include the scale in the photograph, you have a couple of options for scale documentation. At this point, you could attempt to lift the print. The lift will probably come out with sufficient latent print detail, but even if it doesn’t, the outline of the powdered door handle will still give a real size image of the door handle. Measuring this image from the top of the handle to the bottom can give you pretty accurate scale to translate to the photographed image of the latent on the handle. You can even include a photograph of the lift with a scale. The latent print examiner will usually be able to collate this information to correct the size of the latent as needed for entry into AFIS.

At the end of the day, with a little extra effort, some practice, a thorough working knowledge of your standard equipment, and the addition of a simple $2 inspection mirror, you can significantly increase your chances of finding, documenting, and recovering latent prints from this seemingly elusive area: the back of the door handle.


Once latent prints have been developed on the back of a car door handle, they should be photographed in place. To get everything positioned correctly, you may need to tape the mirror to the car door and place the camera on a tripod. Then illuminate the print using the mirror and take a photograph of the image of the print in the mirror. Note that use of a scale using this technique is admittedly difficult, if not impossible.


The photograph of the latent will need to be corrected prior to AFIS entry. The light tends to illuminate the powder in such a fashion that the ridges and valleys of the print appear to be interchanged (essentially a photographic negative of the true print). This is easily done in digital editing software or on an AFIS workstation. Here, the image has been converted to black-and-white and the colors inverted using digital editing software.


Another issue with taking a photograph of a (literal) mirror image is the fact that the resulting image of the fingerprint pattern will be reversed. This is also easily corrected prior to AFIS entry utilizing a “flip horizontal” command in digital editing software, or a similar command on an AFIS workstation. Once these visual corrections have been made, the image essentially becomes the equivalent of a standard latent lift.


About the Author

This e-mail address is being protected from spam bots, you need JavaScript enabled to view it is a sworn officer, full-time crime scene detective, and Master Evidence Technician with the Akron (Ohio) Police Department Crime Scene Unit. He has been a guest instructor with the Ohio Peace Officer Training Academy in London, Ohio for eight years and is currently a guest instructor with the Akron Police Department Police Training Bureau for police academies.

 

 

 
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