Validating IND
(1,2 - indanedione)
Stephen P.
Kasper
Senior Crime Laboratory Analyst
Donna J.
Minnillo
Crime Laboratory Analyst Trainee
Amy M. Rockhold
Forensic Technologist
Florida Department of Law Enforcement
Fort Myers Regional Operations Center
Fort Myers, Florida
Introduction.......Materials.......Safety
Considerations.......Formula
Procedure.......Quality
Control.......Results.......Conclusion.......References
Introduction
Professor Madeleine
Joullié and her graduate students, Drs. Diane Hauze and Olga
Petrovskaia, from the University of Pennsylvania, (Ramotowski et
al. 1997) first synthesized indanediones as intermediates for preparing
substituted ninhydrins for use as a fingerprint reagent. Further
tests by Dr. Tony Cantu of the U.S. Secret Service (Ramotowski et
al. 1997) confirmed that 1,2 - indanedione (IND) could be used as
an amino acid visualizing reagent.
This study involves
the use of IND for detecting latent prints on porous materials by
using its ability to react with the amino acids present in body
protein to produce strongly fluorescent detail when excited with
green light. It was conducted as a validation of the fingerprint
development process described by S. Wiesner et al. (2001), J. Almog
et al. (1999), and E. Menzel (1991). This study was conducted and
submitted for publication in response to the Daubert requirement
that scientific processes be validated and subjected to peer review.
It also serves to fulfill the Florida Department of Law Enforcement
requirement that a new process first be submitted for a validation
study for approval by the technical leader and chief forensic scientist
before it can be used as an accepted process.
Materials
- 1,2 - indanedione
(IND)
- ethyl acetate
- HFE 7100
- Scale, graduated
cylinders, beakers, trays, magnetic stirrer and stirring bar,
amber storage bottles
- Forensic
light source
- Laboratory
oven, photographic-mounting press
Safety
Considerations
The following
safety precautions were adopted:
- Those stated
in the chemical manufacturer's literature
- Use of forensic
light source protective goggles
- Use of fume
hood
- Use of suitable
protective clothing, gloves, and goggles
- Use of precautions
to prevent contact with skin and eyes
Formula
Working Solution
2g............
1,2 - indanedione
70ml........ ethyl acetate
930ml...... HFE 7100
Two grams of IND were dissolved in 70ml of ethyl acetate, and 930ml
HFE 7100 were added to make a final volume of one liter.
Procedure
1. Test specimens
were prepared by placing eccrine perspiration fingerprint impressions
on the various materials listed in Table 1. The same source was
used for all fingerprints, and care was taken to deposit similar
amounts of residue on each type of material. The specimens were
prepared approximately 48 hours before processing.
2. The item
to be processed was dipped, sprayed, or washed with the IND solution
and allowed to dry for approximately three minutes.
3. A photographic-mounting
press or laboratory oven then applied heat, although a hair dryer
or dry iron could also have been used. (When the oven was used,
the item was heated for 20 minutes at approximately 100º C
[212º F]. When the photographic-mounting press was used, the
time was two to five minutes at 100º C.)
4. If possible,
a sample article was tested to determine the maximum temperature
to which it could be subjected without damage. At lower temperatures,
it was heated for longer periods of time, sometimes for several
hours. (When using the photographic-mounting press, the evidence
was placed between two pieces of craft paper because some toner
materials melt and stick to the craft paper if the temperature is
too high.)
5. The item
was viewed under a forensic light source. Wavelengths suitable for
viewing with orange goggles include 450nm, 485nm, 515nm, and 530nm.
For most papers, 515nm appeared to be the optimum wavelength. Manila
envelopes, brown paper bags, cardboard, and craft paper were viewed
at 515nm to 570nm through an orange or red filter.
6. All prints
of potential value were photographed.
Quality
Control
All reagent
working solutions were quality control tested at the time they were
prepared. They were tested daily or before use on actual evidence
and were recorded in both the reagent log and the analyst case notes.
This quality control testing ensured the accuracy of the mixture
and that the desired reaction was obtained.
Initial reagent
formulations contained acetic acid, but it was determined that a
reaction between IND and acetic acid caused a deterioration of the
mixture (Wiesner et al. 2001), thus shelf life is uncertain. Elimination
of the acetic acid resulted in a more stable formula and clearer
fingerprints. The working solution was stored in a dark container.
Results
Samples of various
colored and textured materials were used to test the viability of
IND as a fingerprint development reagent. Two specimens of each
sample were prepared, one sample was heated in a 100º C oven
for 20 minutes, and the other was heated in a photographic-mounting
press at 100º C for two to five minutes. The samples were then
examined using a Crime Scope set to 515nm and an orange barrier
filter (kv55).
The processed
fingerprints developed quickly and completely, particularly when
heated in the photographic-mounting press. The developed fingerprints
viewed under white light appeared to be more in the pink range rather
than the Ruhemann's Purple of ninhydrin. Fingerprints developed
on all porous surfaces processed except the masking tape. Table
1 depicts the result of this test. Note that heating with the
photographic-mounting press produced the best results.
Conclusion
The results
of this study indicate that IND is a very sensitive amino acid reagent.
The primary
benefit of IND is that, because of its fluorescent properties, the
resultant developed fingerprints are clear and well-defined when
illuminated with a forensic light source producing light in the
515nm range. IND worked well on a wide range of porous materials.
As a result, fingerprints on dark or multicolored surfaces can be
recovered through photography.
Fingerprints
that had been developed by ninhydrin were further enhanced by processing
with IND. Evidence known to be last touched at least one year previously
was processed with IND with strong fluorescence resulting in an
identification. When IND and ninhydrin are both used in processing
an item, IND should be used as the primary process.
References
Almog, J., Bahar, E., Dayan, S., Frank, A., Khodzhaev, O., Lidor,
R., Razen, S., Springer, E., Varkony, H., and Wiesner, S. Latent
fingerprint visualization by IND and related compounds: Preliminary
results, Journal of Forensic Sciences (1999) 44(1):114-118.
Menzel, E. R.
Chemical formulations. In: An Introduction to Lasers, Forensic
Lights and Fluorescent Fingerprint Detection Techniques. Lightning
Powder Company, Salem, Oregon, 1991, pp. 42-44.
Ramotowski,
R., Cantu, A. A., Joullié, M. M., and Petrovskaia, O. 1,2
- indanediones: A preliminary evaluation of a new class of amino
acid visualizing compounds, Fingerprint Whorld (1997) 23(90):
131-140.
Wiesner, S.,
Almog, J., Sasson, Y., and Springer, E. Chemical development of
latent fingerprints: IND has come of age, Journal of Forensic
Sciences (2001) 46(5):1082-1084.
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