Poster Sessions Presented at the International Symposium on Setting Quality Standards for the Forensic Community: Part 2 (Forensic Science Communications, July 1999)
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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.
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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. |
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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
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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.