Impression By Traced Forgery

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Robert D. Kullman, Michael Sinke and Erich Speckin

Forensic Document Examiners,  Speckin  Forensic  Laboratories, 2105 University Park Drive, Suite A, Okemos, MI 48864

In the  effort to determine whether it was possible  to successfully “forge”  indented impressions, 39 individuals were  asked  to  trace  entries  on  a prepared  form. An Electrostatic Detection Apparatus (ESDA) was used to develop indented  impressions created  by the tracings.  The developed  impressions were then compared  to the prepared  entries.  The research indicated  that  fully developed  ESDA impressions that  consist  of more than  a short  single stroke  were readily identifiable as the product  of original writing  or the  product  of tracing. Additionally, many  impressions consisting of short  single strokes were also detectable  as authentic impressions or traced  forgeries.  Further,  weak ESDA impressions of more than  2 letters  or formations were also identifiable  as “forged”  tracings.


A document  examiner  in the authors’   laboratory, with  over 25 years of experience  in the field, developed ESDA impressions  of a critical  entry from a medical chart  on  a medical laboratory report generated months after  the  date  of the  critical entry.  During  the deposition  of the examiner,  the defendant’s attorney raised  the  question of forgery. Defendant’s attorney theorized that  someone made  a machine  copy of the page containing the  original  critical entry,  placed  this  machine copy on  top  of the  laboratory report  and  traced the critical  entry, henceforth  creating  the impressions that  were developed  by the examiner. The attorney argued that his client  had not added the critical  entry  to the  chart  but  instead someone had “forged”  the impressions in an effort to bolster their  medical  malpractice claim.

Document examiners  trained  and experienced in ESDA examinations and evaluations  know that ESDA-developed  impressions are duplications of the original  writing  just as a carbon  copy writing is a duplication of the  original  writing. Shifting may occur  between  the transmitter page and the receiver page(s), but the letters,  symbols  or words will overlay each other with  the exception  of writings on the  transmitter page that  are so faint that they  are not  duplicated on  the  receiver  page(s). Such faint  writings are usually  found  where  the writing instrument is gradually placed on or lifted from the Writing surface,  such  as beginning  and / or ending  strokes.

Additionally, it is likely  that  every document examiner  who has completed  a recognized  training program, and has done substantial casework involving ESDA  examinations,   has evaluated numerous ESDA lifts  that  contain  similar  impressions,  and is able to identify  which  ESDA- developed  impressions came from which  transmitter page. These developed impressions may be as limited  as checkmarks, circles  or X’s or as expansive  as sentences,  paragraphs  or complete pages.  It is possible  that  on occasion  these  impressions  have been the result  of someone  tracing over original  writings.

The authors  were unable  to locate any articles concerning  traced  or forged impressed  writings, and therefore  agreed to conduct  research  to determine if ESDA-developed indented writing impressions produced  by traced forgery could be distinguished from  indented  impressions made as the result  of original  writing.

Methods and Materials

Using the  theory  that  prompted this  research, the authors  developed  a form consisting  of short phrases  of printing  and cursive writing,  symbols and numbers  commonly  found in medical charts. The form  consisted  of a top “transmitter”   page (Figure 1) and two blank  pages, receiver pages 1 and 2, of unlined  white  Hewlett  Packard 8 1/2 by 11 inch Office Paper that  were secured  together by stapling  at the  top, bottom  and each side to prevent  shifting. Each packet  was numbered 1 through 39. Each page within the packet was numbered with the packet number followed by a 1for the transmitter page, a 2 for the first receiver page and a 3 for the second receiver page. For example, 30-1 was used for the Test 30 transmit- ter page, 30-2 for the first receiver page of Test Packet 30 and 30-3 for the second receiver page of Test Packet 30.

The participants in this study were the faculty and staff of a school district in the central Michigan area. Forty-five packets were distributed with 39 respondents. Twenty-four of the participants were male  and 14 were female with  1 form undesignated..   Thirty-three were right-handed and 4 left-handed with-Z forms undesignated (Fig- ure 2). The ages of the’ participants ranged from 24 to 73. Since ballpoint  pens produce  the best ESDA-developed impressions  (Baier, 1983), directions to the participants were to “use a ball point pen and carefully  trace over the following  writings.  After you complete  the project, please fill out  the  information at  the  bottom  of the  page and return  in the enclosed  envelope.”

When the completed  test packets were returned to the  authors’ laboratory,  the  staples  were removed,  with  the  exception  of the  staple  at the top of the packets,  and the pages were fanned in an effort to separate the pages. Since this research was developed as the result  of a deposition  question concerning  a medical  records examination, the authors  wanted  to simulate  the handling  of medical records of a frequently seen patient. Therefore,  the packets  were placed in a file and every 2 weeks, on the workday  closest to the first and fifteenth  of the month,  the packets  were removed from  the  file and  the  pages again separated by fanning.  The authors  also wanted to see if the storage  and  handling  of the  test  packets had  any  noticeable impact on  developing   the ESDA impressions.   Three months  after receiving the  test  packets,  ESDA examinations were conducted.

The first step of the examination  was to review the  transmitter    page of all the  test  packets  for accuracy  of the  tracings. Because of the  closeness  of the  tracings,  the  authors   selected  Test Packets  3, 17, 18, 37, 4o and 41.  None  of these test packets had accurate tracings throughout,  but each had a portion at the transmitter page that exhibited close tracings.

Prior to conducting  ESDA examinations of the test  packet  receiver pages, a standard  test  of the laboratory’s ESDA was performed  to ensure  reproducibility and sensitivity   of the  instrument. The laboratory’s  ESDA room is maintained with a relative  humidity between  52 to 6o%  (Foster and Freeman,  undated). The standard  test  is to place  the  “receiving” document in  a humidity chamber  to readily obtain an electrostatic charge (Beal, 1998) for 3 minutes.   After 3 minutes of humidification,   the  document is placed  on the ESDA vacuum plate and  the  vacuum pump turned  on.  The polymer  imaging film is placed over the document  and vacuum  plate, thus sandwiching the document  between  the imaging film and vacuum  plate. Then the surface of the imaging film is charged with  2o passes of the  corona positioned 1 1/2 to 2 1/2 cm above the film (Foster and Freeman, undated). The vacuum plate, which is hinged on one side, is raised  5 to 8 cm and the cascade developer is cast across the imaging film the entire  length  of the  document.   The  casting of developer  is repeated  three  more times  before the adhesive  fixing film is placed over the imaging film to complete  the ESDA lift (Figure 3). In the top portion  of Figure 3 the  black  writing  is the developed impression  on the ESDA lift while the  white  writing  is the  original  writing  on the transmitter page.  The bottom  portion  of Figure 3 depicts  the  ESDA lift  overlaying  the  original transmitter page writing.

Following the  test  of the  instrument,    the  authors separated the  selected   packets and  conducted  ESDA examinations on the two receiver pages. The ESDA examinations  of the test packet pages were not limited  to 20 corona passes and 4 developer castings, but instead each test page was processed  until  the  authors  believed  that  maximum  development  had been reached. Figure 4 is a typical  example  of a developed ESDA lift.


Evaluations of the ESDA-developed impressions were conducted using the original  written  form. Evaluation of the ESDA lifts was done by aligning the lift  directly  on the  original writing and placing a white  piece ‘Ofpaper between  the two. The paper  was moved back  and  forth  to reveal the original writing and impressions  while studying the  area with  magnification.   If the ESDA impressions did not overlap  the  original writing and  instead   deviated  from  the  original written linets],  then  the  impressions   could  not  be the product of the original writing.  The authors found that  the  impressions developed  on all  6 of the first receiver  pages were easily detectable  as not being the product  of the original  writing, except for the single number 1 on Tests 17, 18, 37, 40 and 41. All the impressions   on Test 3 could readily be detected as not being the result of the original writing (Figures 5, 6 & 7). In Figures 5, 6 and 7, the black writing is the developed impres- sion on the ESDA lift while the white writing is the original writing on the transmitter page.

The authors  used this  same evaluation  method to compare the ESDA lifts with  a first generation machine  copy of the original writing and the findings  did not  differ as a result  of using  the  machine copy instead  of the original writing  (Figure 8). In Figure 8, the black writing  is the developed impression while  the  white  writing   is from  a machine  copy reproduction of the original writing on the transmitter page.

While almost  all of the  ESDA-developed im- pressions of the traced entries were easily detectable as not being the product  of the original writing, the impressions  developed from the untraced writing  at the  bottom of the  transmitter pages were readily identifiable as the product  of original Writing. The  left portion  of Figure 9 shows ESDA impressions of the  date  “9-20-00and a circle developed from Test 3.  The black writing in this  figure is the  developed  impression  while the white  writing is the  original  writing  on the transmitter page. The right  portion  of Figure 9show the ESDA impressions  from Test 3-2 overlaid with  the  original  writing  and can clearly be identified as originating from  transmitter page Test 3-1.

All of the first receiver  pages in the test packets  developed  strong  ESDA impressions, as did all, except Test 40, of the  second receiver  pages (labeled 40-3). The  faint  ESDA lift 40-3 (Figure 10) was compared  with  the original written  form and some  of the  numbers   and single  letter  for- mations  could not  be identified  as “forged” impressions. However,  any combination of letters and/or letters with symbols, such as the “W” with a horizontal  line above it, the printed  “no” or the cursive  “pt” could  readily  be detectable as not the product  of the original writing  (Figure 11). In Figure II,  the black writing  is the developed impression while  the white  writing  is the  original writing  on the transmitter page. Again, using the same  evaluation method to  compare  the  faint ESDA lift 40-3, with  a first generation machine copy of the  original  writing, the  authors  found no  differences  as a result  of using  the  copy instead of the original.

An examination of the first receiver page from all the test packets revealed deep and readily visible impressions of the traced information (Figure 12), with the  exception of Test  Page 40-2, which  contained  traced portions  too faint for ob- servation  without the ESDA examination. This information is being  reported  as an observation only and  had  no  impact on  the conclusions of the study.


The results of this study indicate that fully de- veloped ESDA impressions consisting of more than a short single stroke are readily identifiable as the product of original writing from a transmitter page or a product of tracing. Additionally, many impressions consisting of short single strokes are also detectable as authentic impres- sions or traced forgeries. Further, weak ESDA impressions of more than 2 letters or formations are also identifiable with the transmitter page or as “forged” tracings.

As with all document examination, care should always be used in the development and evalua- tion of ESDA impressions.   When evaluating ESDA-developed impressions, it is necessary to evaluate the possibility of forged impressions.


Baier, Peter E. (1983). Application of Experimen- tal Variables to the Use of the Electrostatic De- tection Apparatus, Ioumal of Forensic Sciences, Vol. 28, No.4, p. 905.

Beal, Bonnie 1. (1998). Effects of Water Temperature vs. Time in Humidifying Documents For Electrostatic Detection Apparatus (ESDA) Ex- amination, presented at the Midwestern Asso- ciation of Forensic Scientists Workshop, Ann Arbor, MI.

Foster and Freeman, updated.   ESDA Operating . Instructions.

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