|
|
|
October 1999 Volume
1 Number 3
Poster
Sessions
Presented at the
2nd International Symposium on the
Forensic Examination of Questioned Documents
Albany, New York
June 14 – 18, 1999
Part 2
The following abstracts
of the poster sessions are ordered alphabetically by authors'
last names.
Evaluation of Documents Produced by a
High-Speed, High-Volume, Commercial Scanning Process
L. A. Mohammed
San Diego Sheriff's
Crime Laboratory
San Diego, California
Introduction
Original documents are always
preferred by the document examiner; however, circumstances sometimes
dictate that copies be examined. Examiners are well aware of
the dangers inherent in photocopied or microfilmed documents.
More recently, documents are being scanned by commercial scanners
and are stored as digitized images.
These scanners typically
scan at 200 dpi, which provides a compromise between legibility
of the image and storage space. Some banks and courts, as an
alternative to microfilming, are using this method of archiving
or storing documents. Document examiners may soon begin to see
prints of these scanned images as questioned and specimen documents.
This study was done to evaluate
the suitability, for examination, of documents produced by a
commercial scanner.
Method
Several features that could
be important in the determination of authenticity of scanned
documents were evaluated. Documents were prepared which bore
the following:
- Signatures (genuine, traced,
tremulous).
- An alteration by means of
correcting fluid.
- Typewritten entries.
- A rubber stamp impression.
- Laser and inkjet printing.
- A fold and staple holes.
|
These documents were then
scanned at 200 dpi using a Fujitsu Duplex 3093 DG (Fujitsu Computer
Products, Milpitas, California) scanner. The software used was
Westbrook File Magic (Westbrook Technologies, Branford, Connecticut).
The scanned images were printed on a laser printer.
Results
Overall, the images were
85-95 percent the size of the original. The genuine signatures
were reproduced well pictorially, but some of the fine lines
appeared as clear breaks or pen lifts (see original signatures,
above right). Gross tremor was clearly seen in the scanned image
(below right). A clearly visible penciled guideline on an original
traced signature was not reproduced in the scanned image. Remnants
of a guideline were seen in the scanned image of another traced
signature (below, left and right). However, evaluation of these
remnants as a guideline from only the scanned image would be
almost impossible. |
Original signatures.
Scanned signatures (traced, 2X genuine, tremulous). |
Alteration by correction
fluid. |
Scanned image of
alteration and traced signature. |
|
The alteration by use of
correcting fluid was only partially reproduced, and it would
be difficult to evaluate this type of alteration from the scanned
image.
The rubber stamp impression
reproduced well (right, top and bottom) but not some of the serifs
in the typewritten entries (below, left and right). The scanned
laser and inkjet printing could not be differentiated from each
other. However, a drum defect from the original laser printing
was clearly seen in the scanned image. The staple holes were
clearly reproduced as printed marks, but no evidence of the fold
was seen in the scanned image. |
Rubber stamp impression.
Scanned image of rubber stamp impression. |
Typewriting. |
Scanned image of typewriting. |
Conclusion
In this high-speed, high-volume
commercial scanning process, gross features are reproduced, whereas
subtle features quite often are not. These latter features are
of great significance in the determination of authenticity of
a document. An examiner should, therefore, proceed with extreme
caution when examining documents produced by this process. Improper
evaluation of these documents could lead to erroneous conclusions.
The author wishes to acknowledge
the assistance of Document Imaging Service Corporation, San Diego,
California, in the preparation of this manuscript.
Four Writing Instruments, Two Writing Surfaces,
and One Writer
T. L. Moran
United States Secret
Service
Washington, DC
Over the past several decades,
forensic document examiners have experienced vast growth and
expansion in their professional responsibilities. This is a result
of the introduction of new writing instruments, technological
advances, and possibly more streetwise criminals. In general,
forensic analysis requests have become more complex, often involving
multistep examinations. For many examiners, cases requiring only
a comparison of handwriting are in the minority. However, it
is not to say that much satisfaction and significant conclusions
cannot be drawn from cases that are made by applying the basic
technical skill that puts the questioned document field on the
forensic map.
 This case involved an employee who
sent handwritten harassing letters first to supervisors and then
to peers. The harassing letters began to surface shortly after
an unfavorable review was given to the employee regarding his
performance. As the letters accumulated and their origin remained
unknown, the necessity of a handwriting comparison became inevitable.
The examiner was presented with five questioned documents bearing
handprinted threats. The first request was to determine if all
the writings were the product of one writer or several writers.
Four of the five letters were written with different writing
instruments and on two different substrates. One substrate was
paper, and the other was paper overalls. The paper overalls were
textured, creating an uneven writing surface and therefore adding
a challenge to the examination. Pencil, ballpoint pen, and thin
and thick felt-tip pens were used to execute the various threats.
The chart at right was prepared to illustrate some of the characteristics
that were evaluated during the comparison process.
Initially evaluating the
evidence, the examiner surmised that the loss of detail that
sometimes results when writing appears on uneven surfaces and/or
is executed in pencil or felt-tip pen can hinder the association
of some documents with each other, assuming they were produced
by one individual. Fortunately for the examiner, a thorough examination
and comparison of all the documents revealed many recurring individual
and class characteristics regardless of the writing medium or
surface involved. In this case, it was very helpful to have several
documents to compare to one another. Without a collective consideration
of all the documents, the examiner may not have been able to
make an association.
Eventually, the normal course-of-business
writings of a few employees were submitted. An examination and
comparison of questioned to known revealed that a writer of the
submitted known writings was the writer of the harassing letters.
Attached is a chart illustrating some of the characteristics
that were evaluated during the comparison process.
Recovery of Evidential Images From
Color Polaroid Land Negative Sheets
R. T. Picciochi
New York City Police
Department
Jamaica, New York
and
J. Fiertner
Nassau County Police Department
Mineola, New York
In many investigations, photography
is one of the most basic and useful tools forensic document examiners
rely upon. The document examiner often uses specialized photographic
techniques to make clear what otherwise may be hidden or indistinct.
In this case, investigators recovered color Polaroid negative
sheets from a crime scene. Although they are normally discarded,
the negative sheets contained faint ghostlike images that were
capable of being enhanced. The negatives were submitted in hope
of recovering images of a suspect who was photographed just prior
to committing a crime.
The peel-apart color negative
sheet used to form a Polaroid print is not a negative in the
traditional sense: It is opaque and cannot be used to make a
photographic print. If the image could be removed from its opaque
backing and transferred to a clear glass substrate, then it could
be contact (or projection) printed, like a standard negative.
Initial attempts were made
to obtain an image by employing the VSC2000 instrument and traditional
photography. Various films, filters, exposure times, and lighting
techniques (standard 45 degree reflected, oblique, transmitted,
ultraviolet, and infrared) failed to yield useable images. A
somewhat novel approach to recovering the images using the emulsion
transfer process was attempted. The emulsion transfer process,
a photographic postprocessing technique, is an unconventional
method that employs the removal of the top image layer from a
Polaroid print and transfers it to a nonphotographic receptor
(e.g., cloth, glass, paper). This process has been used by fine
art photographers for some time. The initial step of the process
requires submerging the image (usually the print, but in this
case the negative sheet) in a tray filled with boiling water.
This causes the emulsion layer to be released. However, once
it is wet, the dye layer unexpectedly brightens. Now visible,
the submerged image can be readily photographed rather than completing
the emulsion transfer as intended.
The emulsion transfer process
can be employed to recover faint images from Polaroid color negatives.
Although the image of a dry negative is barely discernable, negative
sheets submerged in water yield clear images. It is not necessary
to complete the process to obtain results. Left to dry, the patent
images once again become indistinct, but may be reprised multiple
times.
References
Step-by-Step Guide to
Emulsion Transfer,
Polaroid Publication No. PID 1E8539. Polaroid Corporation, Cambridge,
Massachusetts, 1995.
Emulsion transfer, test online.
Available at www.Polaroid.com/work/pro-photo/creativeuses/emulsionxfer/howto.html
Infrared Luminescence, Transmitted Light, and
a PS 89 Wide-Field MagnifierCAn Alternate Method of Deciphering the Undecipherable:
A Case Report
D. D. Reed
Arkansas State Crime
Laboratory
Little Rock, Arkansas
In December 1997 an interesting
case was submitted to the Questioned Document Section of the
Arkansas State Crime Laboratory. Conventional photographic techniques
regarding ink were combined with alternate methods of examination
to decipher the writing on an unusual writing surface.
Police officers while having
lunch at a local restaurant were notified by an anonymous caller
that a message had been left for them at the police station.
The caller threatened mass violence if his demands were not met.
Upon arriving at the police department, the officers found three
black long-sleeved thermal shirts on the trunk of a patrol car
which contained writing across the front and back of the shirts.
The writing was produced with a black magic marker-type writing
instrument and was not decipherable. The evidence was submitted
to the Arkansas State Crime Laboratory for analysis.
The evidence was photographed
on a Polaroid MP-4 Land Camera copy stand using Kodak High Speed
Infrared 4 ´ 5 type 4143 film. A No. 87 Wratten
Gelatin filter (75mm ´ 75mm) was used which is transparent
to infrared (IR) light from 740nm and higher and reflective to
the visible spectrum at 740nm and below. The fibers in the polyester
and cotton blend on the shirts reflected more IR light within
the target spectrum (above 740nm) than the ink, thus recording
as tonal differences on the IR negative film producing a lighter
more decipherable image on the negative. The writing was examined
by viewing the negative on a Porta-Trace transmitted light box
with a PS 89 wide-field magnifying lens.
Although the use of microscopy
and direct or oblique lighting have traditionally been used in
conjunction with printed photographs, in this particular case
the tonal differences were more visible using a 4 ´
5 negative, transmitted light, and a wide-field magnifier to
decipher the writing.
Motor Vehicle Certificate of Title Examinations
and Comparisons
M. A. Reid
Federal Bureau of
Investigation
Washington, DC
The National Motor Vehicle
Certificate of Title File at the Federal Bureau of Investigation
is referenced to aid in determining whether questioned certificates
of title are authentic. There are numerous examinations which
can be conducted when examining certificates of title. Examinations
include a side-by-side comparison of the questioned certificate
of title with a known standard having a corresponding state,
form number, and date. Some of the means which reveal the differences
between genuine and nongenuine certificates of title include:
- Measuring various aspects
of the document to determine paper thickness and marginal and
border widths.
- Using a video spectral comparator
to observe any fluorescing qualities within the paper.
- Using magnification and
lighting to observe various printing processes, watermarks, microprinting,
trashmarks, or other imperfections in the reproduction of the
title.
- Checking the serial numbers
on several titles for repetition.
Once these examinations are
conducted, it can be determined whether a questioned certificate
of title is consistent with the available known standards, thereby
revealing even the most subtle attempts of forgery.
Examples of Individual Characteristics
K. M. Storer
United States Secret
Service
Washington, DC
A basic principle in handwriting
identification is that no two people write exactly alike. Each
writer possesses a certain level of skill, coordination, and
artistic ability. As a writer becomes graphically mature, the
writer concentrates on transmitting thoughts and ideas and not
on the formation of learned letter forms. Individual characteristics
appear in the writing. Individual habits manifest in features
such as shape, size, slant, speed, formation, beginning and ending
strokes, and other features. Identifying, distinguishing, and
assigning weight to individual and class characteristics are
a vital part of handwriting examinations. Individual characteristics
can be unusual or rare; however, the combination of individual
characteristics makes handwriting unique. To render an identification,
there must be agreement in the class and individual characteristics,
and differences must be accounted for due to variation or accidentals.
If there are many differences, they must be far outweighed by
agreement in the remaining characteristics. It is the combination
of individual characteristics with no basic differences that
individualizes handwriting and makes it identifiable to the exclusion
of all others.
The author will demonstrate
numerous individual writing characteristics found within her
casework during the past year.
Examination of Accessories and Components of
a Word Processor Results in Developing Inculpatory Evidence and
Investigative Leads: A Case Study
J. L. Streeter and K. B. Zercie
Connecticut State Police
Meriden, Connecticut
Forty-four stolen business
checks displaying questioned endorsement signatures and signature
exemplars obtained from three suspects were submitted to the
Connecticut State Police Forensic Science Laboratory for comparative
examination purposes. The police report accompanying the submitted
materials reflected that several carbon copies of records stubs
for some of the stolen checks and a word-processing device had
been confiscated at one of the suspect's homes.
Systematic review of the
typewritten entries in the information sections on the face of
the questioned checks revealed numerous similarities in both
the type characteristics and format. The agency requesting the
examination was contacted and advised to submit the word-processing
device for appropriate forensic examination.
Subsequent macroscopic and
microscopic examination of the word processor's accessories and
components resulted in the following:
- The first and last names
of one suspect, who had denied any knowledge of and/or involvement
with the word processor, were discovered typed on the face of
the typing platen.
- All of the information appearing
in the typewritten entries in the information sections on all
of the 44 questioned checks, including the names of the three
suspects, was discovered on the type ribbon of the cassette in
the processor.
- Fracture analysis was conducted
between individual type characters appearing on several of the
questioned checks and the same type characters appearing on the
type ribbon. Sufficient similarities in individual characteristics
were discovered in both the questioned characters and the same
characters on the ribbon to positively identify this particular
ribbon as having produced the questioned typing on the checks.
- Information was discovered
on the type ribbon reflecting that several other checks, which
had not been cashed, had not been confiscated by the police and/or
had not completed bank processing, were prepared on the processor.
At the time of this discovery, the requesting agency was not
aware of the additional checks.
- Information was also discovered
on the type ribbon identifying two additional suspects for whom
stolen checks had been prepared. At the time of this discovery,
the requesting agency was not aware of these additional suspects.
- Review of the catalog of
the information stored on a data disk in the processor revealed
that it contained a document entitled Jail Bait. This
document was the base format (boilerplate) of information to
be typed on the face of the questioned checks.
- Also discovered on the data
disk were several personal documents (employment history, resume,
personal letters) of one of the original three suspects who had
denied any knowledge of and/or involvement with the word processor.
- Comparison examinations
between the endorsement signatures appearing on the questioned
checks and known signatures of the three known suspects resulted
in positively identifying each suspect as having authored their
signatures on several of the checks.
- All of the questioned checks
were chemically processed for latent finger and palm prints.
Latent prints identified as belonging to three of the five suspects
were discovered on several of the checks.
As a result of the information
developed during the various laboratory examinations, all five
suspects elected to forego any trial process and pled guilty
to various criminal charges.
Investigators and document
examiners should be conscious of, and employ, all aspects and
techniques of document examinations available in a particular
case. These techniques, as outlined in this particular case,
can often result in developing additional investigative leads
and extremely important inculpatory information.
Back
to index
FORENSIC SCIENCE COMMUNICATIONS OCTOBER 1999 VOLUME
1 NUMBER 3 |
