Forensic Databases: Paint, Shoe Prints, and Beyond
by Robin Bowen and Jessica Schneider
About the Authors
Ms. Bowen is the forensic program coordinator for the Forensic
Science Initiative at West Virginia University. Ms. Schneider
is a graduate student in public administration at West
Virginia University.
A detective working a missing persons case undoubtedly knows
how to make the most of databases such as the Combined DNA
Index System (CODIS) and the Integrated Automated Fingerprint
Identification System (IAFIS), but does he or she know how
to investigate a paint chip, a tire track, an ink sampling,
or a piece of glass?
Many government and private forensic databases can help both
law enforcement investigators and the scientists who support
their work in the lab. To help spread the word about the
existence of these tools, the National Institute of Justice
(NIJ) funded West Virginia University to gather the following
basic information.[1]
Integrated Ballistic Identification System: IBIS
Maintained by the Bureau of Alcohol, Tobacco, Firearms and
Explosives National Integrated Ballistic Information Network,
this forensic database contains bullet and cartridge casings
that have been retrieved from crime scenes and test-fires of
guns found at a crime scene or on a suspect. One limitation
of this database is that there must be a suspected gun to
make a comparison. Because the database contains information
on bullets and casingsand not on specific gunsa
test-fire bullet from a gun must be compared to a bullet
found at a crime scene, for example, to determine whether
a bullet came from a specific gun. Any image of a casing
or bullets must be sufficiently cleanthat is, be
clear, show characteristics, and have little glarefor
a comparison to be valid.
How does IBIS work? Technicians use forensic imaging
technology to enter bullet and casing evidence into IBIS.
New images are correlated against data, and technicians
are alerted to possible matches. At that point, a firearms
examiner uses a comparison microscope to perform a manual
examination. For more information, see
www.atf.gov.
Paint Data Query: PDQ
Maintained by the Royal Canadian Mounted Police (RCMP), PDQ
contains the chemical compositions of paint from most domestic
and foreign car manufacturers and the majority of vehicles
marketed in North America after 1973. The PDQ software is
free to agencies that supply a minimum of 60 paint samples
per year. The database information comes from the street (more
than 60 percent from body shops and junkyards) and from
manufacturers. In 1998, RCMP entered into agreements with the
German Forensic Institute and the Japanese National Police
Agency, which resulted in 1,500 samples being added to the
database each year. Not all manufacturers, however, are
willing to divulge the chemical composition of paint used
on their vehicles. If a particular sample has not been
entered into the database from the street, it would not be
possible to obtain a match.
How does PDQ work? Each paint layeran automotive
paint job usually consists of fouris examined to
determine the spectra and chemical composition. The chemical
components and proportions are coded into the database.
These known samples are compared against a paint sample from
a crime scene or a suspects vehicle to search the make,
model, and year of manufacture of a vehicle involved in a
hit-and-run or other criminal activity. For more information,
see www.rcmp-grc.gc.ca Exit Notice.
National Automotive Paint File
This Federal Bureau of Investigation (FBI) database contains
more than 40,000 samples of automotive paint from manufacturers.
How does the database work? Paint chips from cars can
be compared to samples in the database. Undercoats help to
narrow down possible manufacturers. For more information,
contact the FBIs Laboratory Division at 202-324-3000.
Glass Evidence Reference Database
This database contains more than 700 glass samples from
manufacturers, distributors, and vehicle junkyards. It is
housed by the Technical Support Working Group, an
interagency group that includes the U.S. Department of State
and the U.S. Department of Defense. Although it cannot
determine the source of an unknown piece of glass, the
database can assess the relative frequency that two glass
samples from different sources would have the same elemental
profile.
How does the database work? Two plasma mass spectrometers
are used to perform an elemental analysis of glass. For more
information, e-mail isfsubgroup@tswg.gov.
TreadMark™
The number of shoe prints at a crime scene can be so large
that the process of impression recovery becomes very
time-consuming. TreadMark™ is a commercial product that
uses four parameterspattern, size, damage, and
wearto identify individual outsole impressions. These
are then compared with shoe print data from two sources:
suspects in custody and crime scenes. A match could yield
the name, date of birth, criminal record number, places of
interest, and similar offenses for possible suspects.
How does TreadMark™ work? Impressions from a
crime scene are obtained using the current recovery methods
of photograph, gel lift, dust lift, and adhesive lift.
These are input directly into the analytical system by
high-resolution digital imaging. The same procedure is used
with an impression of a suspects shoe print: It is
photographed using a high-resolution digital camera, and
these impressions (along with the offenders details) are
input into the analytical system, where the operator can
measure, analyze, and compare crime-scene and suspect
images. Both image sources can be searched within themselves
and against each other, allowing such images to be
transmitted to other users. For more information, see
www.csiequipment.com/systems.aspx Exit Notice.
SoleMate
This commercial database contains informationmanufacturer,
date of market release, an image or offset print of the sole,
and pictorial images of the uppersfor more than 12,000
sports, work, and casual shoes. Sold on DVD, the product is
updated and distributed to subscribers every 3 months. One
limitation is that different manufacturers often use the
same sole unit. Therefore, it may be difficult to determine
the exact make and model of a shoe. The software links such
records, however, so that all footwear that might match a
crime-scene print can be considered.
How does SoleMate work? The pattern of an unidentified
shoe print is assigned a set of codes to isolate basic features,
such as circles, diamonds, zigzags, curves, and blocks.
Options, with variations, are presented pictorially, which
allows an investigator to code features that best match the
shoe print. These codes form the database search, with results
presented in descending order of pattern correlation. For more
information, contact Foster & Freeman USA Inc., at 888-445-5048.
TreadMate
Maintained by the same United Kingdom company that markets
SoleMate, this database contains information on more than
5,000 vehicle tires and tire tread patterns, including
manufacturer, date of market release, pictorial image, and
pattern features. Because manufacturers sometimes use the
same tread, it may be difficult to find the exact make and
model match of a tire. In these cases, records are linked
so that all tires that might match a crime-scene tire mark
may be considered.
How does TreadMate work? The pattern of an unidentified
tire mark is assigned a set of codes for pattern features,
such as waves, lines, diamonds, zigzags, curves, and blocks,
which then form the basis of the database search. Results
are presented in descending order of correlation. For more
information, contact Foster & Freeman USA Inc., at
888-445-5048 or usoffice@fosterfreeman.com.
Forensic Information System for Handwriting: FISH
Maintained by the U.S. Secret Service, this database enables
document examiners to scan and digitize text writings such
as threatening correspondence.
How does FISH work? A document examiner scans and
digitizes an extended body of handwriting, which is then
plotted as arithmatic and geometric values. Searches are
made on images in the database, producing a list of
probable hits. The questioned writings, along with
the closest hits, are then submitted to the Document
Examination Section for confirmation. For more
information, see
www.secretservice.gov/forensics.shtml.
International Ink Library
The collectionmaintained jointly by the U.S. Secret
Service and the Internal Revenue Serviceincludes
more than 9,500 inks, dating from the 1920s. Every year,
pen and ink manufacturers are asked to submit their new
ink formulations, which are chemically tested and added
to the reference collection. Open-market purchases of pens
and inks ensure that the library is as comprehensive as
possible.
How does the library work? Samples are chemically
analyzed and compared with library specimens. This may
identify the type and brand of writing instrument, which
can be used to determine the earliest possible date that
a document could have been produced. If the sample matches
an ink on file, a notation is made in the database. The
U.S. Secret Service generally provides assistance to law
enforcement on a case-by-case basis. For more information,
contact 202-406-5708.
Ident-A-Drug
The Therapeutic Research Center, a private company, publishes
a computer program and book to help identify drugs in tablet
or capsule form. To make an identification, sufficient
information about the unknown drug must be available.
How does Ident-A-Drug work? Data used for comparison
purposes contain codes that are imprinted on tablets and
capsules, information on color and shape, the national
drug code (NDC #), and drug class. Schedule information
is shown if the drug is a narcotic or in one of the U.S.
Drug Enforcement Administration schedules. For more
information, see
www.therapeuticresearch.com Exit Notice.
PharmInfoNet
This free Internet database contains information on
prescription drugs, including uses, marketing and
availability, and common side effects.
How does PharmInfoNet work? To perform a search, the
generic or brand name of the drug must be known, which may
not be possible if only a portion of the drug exists or the
drug is not marked with a name.
RxList
Another free Internet database of prescription drugs is RxList.com.
How does RxList work? As with PharmInfoNet, the name
of the drug must be known. Information in the database may
not be current because new drugs are created regularly and
new side effects are discovered. Search results include
patient summaries; side effects and interactions; and links
to public health, policy, and economic information. For
more information, see
www.rxlist.com Exit Notice.
Ignitable Liquids Reference Collection: ILRC
Maintained by the National Center for Forensic Science,
this database and associated liquid repository allows a
laboratory to isolate an ignitable liquid of interest for
inclusion in an inhouse reference collection. Designed for
screening purposes only, it parallelsbut does not
replaceAmerican Standard Testing Materials requirements
for an inhouse reference collection. A laboratory does not
need to adopt the ILRC classification system to use this
database.
How does ILRC work? Users enter the name of the
liquid into the searchable database. The database can also
be organized by classification of the liquid for quick reference.
Users can then purchase samples of the liquid. Commercial
samples are obtained directly from manufacturers and
distributors. The products are then repackaged for
distribution using the product name and sent to forensic
science laboratories. For more information, see
www.ncfs.org Exit Notice.
ChemFinder
This free Internet-based database contains information from
manufacturers on chemicals, including chemical structures,
physical properties, and hyperlinks.
How does ChemFinder work? Searches are conducted
using a chemical name, Chemical Abstract Service (CAS)
registry number, molecular formula, or weight. For more
information, call 800-315-7300 or see
http://www.cambridgesoft.com/databases/login/?serviceid=128 Exit Notice.
Integrated Automated Fingerprint Identification System: IAFIS
This FBI-maintained database contains:
- Fingerprints acquired after arrest at the city, county,
State, and Federal levels.
- Fingerprints acquired through background checks for
employment, licensing, and other noncriminal justice
purposes (if authorized by State or Federal law).
- Latent prints found at crime scenes.
Although IAFIS offers electronic search and storage
capabilities, it has some limitations. The database contains
the fingerprints of only a small percentage of the population.
Moreover, to make a comparison, the latent print must be
of sufficient quality to identify certain individual
characteristics. For example, the cores and deltas must be
present in the print to determine the orientation of the print.
How does IAFIS work? The database receives data
electronically, in hard copy, or in machine readable data
format. IAFIS accepts, stores, and distributes photographs,
including the results of remote 10-print and latent searches.
These are returned electronically to the requesting agencies
with a list of potential matching candidates and their
corresponding fingerprints for comparison and identification.
For more information, see
http://www.fbi.gov/about-us/cjis/fingerprints_biometrics/iafis/iafis
or contact the FBIs Criminal Justice Information Services
Division at 304-625-2000.
Combined DNA Index System: CODIS
This FBI-run database blends forensic science and computer
technology into a tool for solving violent crimes. CODIS
enables Federal, State, and local crime labs to exchange
and compare DNA profiles electronically, thereby linking
crimes to each other and to convicted offenders. CODIS uses
two indexes: (1) the Convicted Offender Index, which
contains profiles of convicted offenders, and (2) the
Forensic Index, which contains profiles from crime-scene
evidence.
How does CODIS work? Searches are performed to find
a match between a sample of biologic evidence and an offender
profile. Matches made between the Forensic and Offender
Indexes provide investigators with the identity of a suspect.
DNA analysts in the laboratories share matching profiles,
then contact each other http://www.fbi.gov/about-us/lab/codis/codis.
NCJ 219606
Note
[1] |
The information
in this article regarding manufacturers and products,
including Internet databases, is presented for
informational purposes only. The National Institute
of Justice has not evaluated the utility, accuracy,
or veracity of the data in these databases; no
product approval or endorsement by the U.S. Department
of Justice should be inferred. |