 Document
Examination Unit
 
he Document Examination Unit is a highly specialized forensic
unit within the Scientific and Technological Services Bureau of
the Philadelphia Police Department. The unit responds to all requests
of service concerning the field of Questioned Documents. It is
currently staffed by one Sergeant and is overseen by the Commanding
Officer of the Crime Scene Unit.
Questioned Document Examination is the oldest of the forensic
sciences. In the United States judicial system, it predates
the use of fingerprints as means of identification by seventy-five
years.
To an examiner, a document is any item that can bear a visible
or latent message. Paper, walls, mirrors and chalkboards can
all bear a visible handwritten or machine produced message.
The second sheet of paper on a pad may bear the latent impressions
from handwriting produced on the first sheet. The Questioned
Document Expert attempts to answer the questions of author,
origin, or authenticity. "Who wrote this document?"
"Where was this document produced?" and "Is this
document genuine?"
The majority of the caseload of the unit centers on handwriting
identification. By identifying individual characteristics present
in the handwriting on a questioned document and comparing them
to the individual characteristics of a known person, a Questioned
Document Examiner can identify or eliminate the person as the
writer of the entry.
By identifying paper characteristics, handwriting, ink and
machine produced text, the expert attempts to identify how the
document was produced.
A comparison between a purported document and an authorized
document allows an examiner to determine if the document in
question is actually genuine. Inspection stickers and driver's
licenses are the most often counterfeited documents submitted
for examination.
A Questioned Document Examiner utilizes many instruments during
the course of his examination. Hand-held magnifiers and comparison
microscopes enlarge items for examination. Infrared, ultra-violet
and alternate light sources assist in the differentiation of
inks, the identification of counterfeit documents and the identification
of overwritten entries. The Electro-Static Detection Apparatus
identifies impressions on paper. Photographic and digital enlargements
highlight areas of concentration and make useful court demonstrations.
Although a Questioned Document Examiner is predominately utilized
during the investigation of thefts and forgeries, their expertise
is requested in cases involving harassment and terroristic threats,
robberies, sex crimes, assaults and homicides. During the calendar
year 1999, the unit handled 373 cases. These cases originated
from the Philadelphia Police Department, District Attorney's
Office, City Solicitor's Office, Prison System, Philadelphia
Housing Authority, local law enforcement agencies in Pennsylvania
and New Jersey, and Federal law enforcement agencies.
| Information
listed here is believed to be current at the time of publication.
However, some of the material presented here may have expired
since it was posted. Persons should contact a Philadelphia Police
representative whenever relying on dated material or information
that is subject to change. |
|
| |
|
This page is entitled:
The URL of the page is:
Downloaded at:
|
|
