Written by Cierra Wiggins & Andrew
PHYSICAL EVIDENCE is a common occurrence,
most likely found at every crime scene. Each piece of evidence may provide
investigators with probative information regarding the circumstances of the
event, or the presence of a specific person. The use of gloves is often used in
the commission of a crime, and often collected by crime scene responders for
forensic examination and analysis.
While gloves primarily serve
as a barrier between the skin and the surface being touched, latent impressions
may be deposited on the gloves during use and may be developed and utilized as
a piece of physical evidence. The sequential examination process utilized during
this type of latent print processing may vary, based on the desired contrast of
the impression to the background and the target matrix of the technique
This study examined two
types of gloves—laboratory nitrile and latex—that may be accessible and
commonly encountered during the investigation of a crime scene. They were also
processed using different sequential techniques to examine the developmental
process, as it pertains to the retained matrix of the transferred latent
impression. The reagents used for this examination consisted of: cyanoacrylate
(CA) fuming/dye stain, CA/WetWop, gentian violet (GV), and magnetic powder.
Results suitable for collection were photographed and analyzed for sufficiency.
Resulting data was compared to establish the clarity of examination methods.
This study focused on
the processing of nitrile and latex gloves for each of the sequential
development techniques. A total of six of each type of glove were worn by two separate
donors for approximately 15 minutes, totaling 12 gloves per processing reagent.
The gloves were carefully removed and stored for 48 hours prior to processing.
process was performed using a Foster + Freeman MVC3000 cyanoacrylate chamber in
accordance with current laboratory protocols. A test print deposited using a
Sirchie latent print standard pad was placed on a black fingerprint lift card,
to be run concurrent during the fuming process to ensure development. The
fluorescent dye stain utilized was methanol-based RAM. The gentian violet, RAM,
and black magnetic powder were all manufactured by Evident. The black WetWop utilized
was supplied from Lightning Powder. A SPEX Crimescope was used to view any
development following the application of RAM in the following wavelength and
barrier filter combinations: 415nm/Yellow, 455nm/Orange, and 515nm/Red.
Resulting photographs were captured utilizing the Foster + Freeman DCS5 with a
Nikon D5 digital camera.
The donor gloves were
processed using the development sequences previously described. Following the
application of the four sequential methods on the donor gloves, some overall
general results were observed, as discussed below:
All nitrile gloves developed friction ridge detail, best
observed under 455nm/Orange barrier filter criteria. The anatomical area
yielding the most consistent results were in the palm regions. As the finger
areas began to introduce some textures within the substrate, it could be a
contributing factor to the decrease in suitable latent print detail. The latex
gloves did not consistently yield suitable developed impressions, and often
failed to yield any visualized ridge detail.
All nitrile gloves developed suitable latent
impressions. In these samples, friction ridge detail was developed consistently
in both the palm regions as well as the fingers. The latex samples did yield
some developed latent impressions, however the results were not as consistent
as with the nitrile samples.
The nitrile gloves were inconsistent with their
developed results. Some samples yielded some observed features; however, they
were mostly creases and not developed friction ridges suitable for comparison purposes.
A contributing factor may have been the lack of contrast between the glove and
the development technique itself. All of the latex gloves yielded positive
results when treated with gentian violet independently. Additional samples that
were created and sequentially processed with CA/gentian violet yielded no
discernable ridge detail, possibly due to the absorption of the gentian violet
reagent into the deposited cyanoacrylate residues.
The magnetic powder did develop discernable ridge detail
on both types of gloves; however, the results were deemed to be of higher
quality on the latex gloves than the nitrile gloves. A potential reason for
this development may be the reduced contrast between the glove and the powder
development, and possibly the introduction of textures in the finger areas of
The photographs below
are a depiction of the typical results obtained through the sequential development
processes, as previously described:
Based on the data
collected, it was observed that there was an overall trend in the development
of latent impressions within the types of gloves. Overall, the nitrile gloves
had a more consistent developmental reaction to the reagents used as compared
to the latex gloves. The sequential examination process of CA/dye stain
consistently resulted in a development of impressions suitable for further
examination, in contrast to the latex gloves. Gentian violet, used primarily as
a development technique on adhesive surfaces, also resulted in a consistent
positive reaction on the latex gloves for the development of suitable friction
ridge detail. In contrast, gentian violet applied to the nitrile glove did not
provide the contrast needed to visualize a developed latent fingerprint, but it
did allow for the visualization of the creases present in the donor. The
application of black magnetic fingerprint powder did yield a positive
development on both types of gloves, allowing further examination to be
performed. The sequential application of WetWop did develop suitable
impressions on both types of gloves, allowing this technique to be used on both
During the processing of
evidentiary items, a number of factors may affect the recovery of latent
impressions on a surface. When considering the surface of disposable gloves,
there may be an increase in moisture from the containment of sweat exuded from
the palmar surface of the hand that could compromise the individual characteristics
of the friction ridge skin. Adversely, if gloves have been changed during use,
the surface of the skin may become dry and not have enough matrix to transfer
onto the glove to leave a suitable impression. As individuals are wearing these
types of gloves, additional distortion may occur within the transfer of the
friction ridge characteristics due to pressure, as well as increased lateral
and rotational distortion. As these gloves are manufactured to serve as a protective
barrier between the wearer and the materials being handled, the material the
gloves are manufactured from is made to resist moisture. Thus, the impressions
left by the eccrine perspiration of the palmar surface of the hand is fragile,
and can be negatively impacted by external factors.
During the course of
this study, there were some potential factors that could have affected the
results, or that could have been enhanced to further examine the scope of these
processes. Any variation in the perspiration levels from the donors; friction
caused during removal or movement; and additional variables could have affected
the deposition and retention of the latent print detail on the gloves.
Additional research may be warranted to examine these factors.
The authors would like
to thank the Washington DC Department of Forensic Sciences, Latent Fingerprint
Unit for their support in this study, as well as Trinity Washington University and
the NASA DC Space Grant Consortium.
Cierra Wiggins is a native
resident of the Washington, DC area. Wiggins is an alumna of DC Public Schools
and is currently a rising senior at Trinity Washington University majoring in
Forensic Science. Cierra’s interest in forensics began while taking a forensic
science course in high school. From that class, she decided she wanted to
pursue a career in crime scene sciences, evidence processing, or working for
the Innocence Project. Cierra is currently a Latent Fingerprint Intern at the
Department of Forensic Sciences in Washington, DC.
R. Reitnauer is the Technical Lead Scientist (Fingerprints)
with the Washington DC, Department of Forensic Sciences. He is a practicing
forensic scientist with 13 years of experience as a supervisor, latent print
examiner, and senior crime scene responder. As a technical leader and primary trainer
within his laboratories, Reitnauer is responsible for procedure development,
and development of the evidence processing program. He is an ASCLD/LAB-approved
internal auditor for laboratory standards. To date, he has examined evidence in
over 15,000 cases, 150 crime scenes, and has been qualified as an expert
witness in courtroom proceedings approximately 85 times.
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Reitnauer, A., C. Lahm. (2015) The Use of Colored
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