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Forensic Science Handbook
2013 – Eleventh Edition
A Practical Guide to the Proper Packaging, Transport, and Submission of
Evidence to the DuPage County Forensic Science Center
John E. Zaruba
DuPage County Sheriff
National Sheriff’s Association President, 2009-2010
Forensic Science Center
DuPage County, Illinois
A Division of the DuPage County Sheriff’s Office
Sheriff John E. Zaruba
(630) 407-2000
[email protected]
Chief James Kruse
(630) 407-2003
[email protected]
Director Claire Dragovich
(630) 407-2101
[email protected]
Honor
*
Integrity
*
Quality
In 2006, the DuPage County Sheriff’s Office became only the fourth law
enforcement agency in the United States to earn the prestigious
international ISO 17025 accreditation through the American Society of
Crime Laboratory Directors – Laboratory Accreditation Board. In late 2010
the laboratory successfully completed a five year audit and ISO 17025
accreditation was renewed effective February 17, 2011.
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TABLE OF CONTENTS
General Information and Instructions
4
4
4
5
6
6
7
7
Our Mission
What all Agencies Must Know
Contacting our Scientists
Directions, Appointments, and Hours of Operation
It’s Your Forensic Science Laboratory
Understanding Testing Reports
Complaints
General Submission Procedures
Menu of Scientific Services
9
11
12
13
13
15
16
18
19
21
21
22
23
23
24
Controlled Substances
Explosives
Fibers
Fingerprints
Firearms (Ballistics)
Flammables & Combustibles (Arson)
Forensic Biology & DNA
Glass
Hair
Intoxicating Compounds
Lamps and Filaments
Paint
Shoe & Tire Impressions
Toolmarks
Other Resources
Some excerpts of this handbook were quoted or paraphrased from the FBI Handbook of Forensic Services, which
can be found at http://www.fbi.gov/about-us/lab/handbook-of-forensic-services-pdf.
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Our Mission
The mission of the DuPage County Forensic Science Center is to support the criminal justice system with
accurate, efficient, ethical, and professional scientific services that contribute to a higher quality of life for
the citizens of DuPage County. This mission is achieved by meeting five main objectives:
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Maintaining proper facilities for casework and the receipt of evidence.
Employing and training highly qualified scientists.
Adhering to scientifically accepted procedures and laboratory quality assurance standards.
Reporting analytical findings coherently and efficiently.
Clearly articulating analytical findings in courts of law.
Scientists working within the center have access to state-of-the-art instrumentation, first-class training
opportunities, up-to-date literature, and a large network of professional peers with which to exchange
pertinent information. Collectively, these resources enhance the scientific reliability and accuracy of
information reported by our laboratory.
What all Agencies Must Know
This handbook is an official communication put forth by the DuPage County Sheriff’s Office for the benefit
of all users of its forensic science services. Nonconformity to laboratory policies can result in evidence
being returned to the submitting agency without analysis or the inclusion of language in a testing report or
expert testimony that describes the nonconformity and its effect on evidence examinations.
It is critical that all participants in the DuPage County criminal justice system understand that the
laboratory employs a complex quality-management system that includes carefully documented methods,
scientifically validated procedures, and quality-control policies that are enforced for the benefit of your
agency. They are in place to protect the integrity of the laboratory’s work product and to prevent
complications to ongoing investigations and court proceedings resulting from shoddy laboratory work or
improperly-handled evidence. Each agency that works with the laboratory is, in essence, a part of this
quality-management system and will be asked to adhere to the guidelines and requirements set forth in
this handbook.
Contacting our Staff
Managing Scientists
Jennifer Cones, CLPE, MA
Claire Dragovich,
Quality Manager / Criminalistics Supervisor
Forensic Scientist – Latent Prints / Firearms / Toolmarks
(630) 407-2110
[email protected]
Laboratory Director / Chemistry & Microscopy Supervisor
Forensic Scientist – Drug Chemistry
(630) 407-2101
[email protected]
Douglas Saul, F-ABC
DNA Technical Leader / Supervisor
Forensic Scientist – Forensic Biology / DNA
(630) 407-2105
[email protected]
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Our Scientists and Support Staff
Jillian Baker
Mary Dastych
Forensic Scientist – Drug Chemistry
(630) 407-2103
[email protected]
Evidence Receiving
(630) 407-2111
[email protected]
Roxanne Brooks, CLPE, MS
Forensic Scientist – Latent Prints / Impression
Evidence
(630) 407-2180
[email protected]
Ticia Burgie
Forensic Scientist – Drug Chemistry
(630) 407-2113
[email protected]
Tamara Camp, F-ABC, MS
Mary Margaret Greer-Ritzheimer, F-ABC
Forensic Scientist – Forensic Biology / DNA
(630) 407-2151
[email protected]
Jean Kinnane, MS
Forensic Scientist – Forensic Biology
(630) 407-2109
[email protected]
Alfred Luckas,
Forensic Scientist – Forensic Biology / DNA
(630) 407-2115
[email protected]
MS
Forensic Scientist – Trace Evidence
(630) 407-2092
[email protected]
Timothy Campbell
Vanessa Martinucci, F-ABC, MS
Forensic Scientist – Latent Prints
(630) 407-2095
[email protected]
Forensic Scientist – Forensic Biology / DNA
(630) 407-2096
[email protected]
Sara Norris
Forensic Scientist – Drug Chemistry
(630) 407-2114
[email protected]
Directions
The laboratory is located at the DuPage County Government Center, situated on the east side of North
County Farm Road approximately one half-mile north of Roosevelt Road (Route 38) in Wheaton. Located
in the James “Pate” Philip Forensic Science Center, the laboratory is on the second floor of the 501
building. Follow signs to the Sheriff's Office / Jail and park at the west end of the 501 building.
Evidence Submission
BY APPOINTMENT ONLY
Monday through Friday
8:00 AM to 11:30 AM
12:30 PM to 4:00 PM
Please contact Mary Dastych at:
(630) 407-2111
OR
[email protected]
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It’s Your Forensic Science Laboratory
Sheriff John Zaruba has taken a proactive approach to crime-fighting in DuPage County by investing
resources that allow scientific technology and forensic expertise to aid law enforcement agencies in
solving crimes. Since 1969, the citizens of DuPage County have benefited from the services provided by
the laboratory, which are made available to all law enforcement agencies in the county. As a result, our
criminal justice system is more efficient, more effective, and more prepared to fairly and objectively
dispose of criminal matters brought before it.
In order to fully reap the benefits of these services, each agency within the DuPage County Criminal
Justice System must work in partnership with their laboratory in the following ways:
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Have a full understanding of the laboratory’s capabilities and limitations.
Be specific when requesting services. The role of a forensic science laboratory is to answer
questions. The more specific the questions are, the more specific our answers will often be.
Submit evidence with ample case information such as a copy of an incident report, summary of the
incident, or other narrative describing the crime scene, incident, and persons involved.
Be familiar with your evidence and the case so that laboratory personnel can ask questions if
necessary.
Keep the laboratory posted of changes in case status. If a suspect pleads guilty to charges, or a case
will no longer be adjudicated, contact the laboratory so that the evidence can be returned. This helps
the laboratory minimize its case backlog, allowing results to be returned in a more timely fashion.
Remember that laboratory scientists are required to be objective and unemotional in their casework.
We understand that some cases tug at the heartstrings of our submitting officers and we do
everything possible to prioritize such cases where circumstances require it. But good science can’t
be driven by emotional urgencies.
In the interest of this on-going partnership, the laboratory offers a number of services to enhance
professional awareness of its capabilities:
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The Introduction to Crime Laboratory Services Seminar for submitting agencies.
The Forensic Science Handbook – a practical guide to the proper packaging, transport, and
submission of evidence to the DuPage County Forensic Science Center.
A website, www.dupageforensics.org that allows 24-hour-a-day access to information about our
laboratory.
Ultimately, efforts to enhance this partnership will pay dividends helping to make DuPage County safer for
our citizens and the police officers that work day and night to keep them safe.
Understanding Testing Reports
The laboratory reports its final results and conclusions in the form of a testing report, which is uniquely
identified by the laboratory case number followed by a sequential digit. An example of a unique report
identifier would be 06-0093-03 where:
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06 is the year in which the case was created.
0093 represents the ninety-third case accepted by the lab in 2006.
03 represents the third testing report issued for case number 06-0093.
The results communicated in a laboratory testing report contain observations, interpretations, and
judgments rendered by a scientist who has the requisite training and experience to conduct the analyses
from which the reported information was generated or gathered. Furthermore, it may not be clear from
reading a laboratory report how interpretive a particular result is compared to another. For this reason, all
laboratory results should be considered interpretive in nature so that our scientists may be called to clarify
or defend any information that is found to be ambiguous, incomplete, or confusing.
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Complaints
The law enforcement community of DuPage County is strongly encouraged to voice any dissatisfaction
with our forensic science services or personnel as soon as possible. Complaints should be brought to the
attention of the director by phone or in writing. If it is necessary to bypass the director, complaints may be
forwarded to Sheriff John Zaruba at (630) 407-2001.
It is vitally important for any instances of substandard service to be reported in a timely fashion.
Complaints are often the first step towards improving an organization’s level of service.
To report a complaint to the interim laboratory director please call (630) 407-2102 or email the interim
director at [email protected].
General Submission Procedures
This section is intended to provide basic instructions for the submission of evidence to the laboratory. No
set of instructions, however, can encompass every possible scenario that may arise. Common sense
should always be exercised in the collection, preservation, and transport of evidence. Be sure to read the
section titled “Special Considerations” for more information.
1.
Place evidence exhibits in appropriate containers. Large and bulky items that do not lend
themselves to packaging may be submitted without packaging if contamination, degradation, or
evidence alteration is not an issue.
2.
Seal each container with tamper-indicating tape.
3.
Handwrite your initials and the date across the tape and onto the surface of the package.
4.
Complete and attach a laboratory evidence label for each of your packages, or label each item
with same information.
DUPAGE COUNTY CRIME LABORATORY
EVIDENCE/ITEMLABEL
Please attach completed label to each package or item.
AGENCY________________________________________________________
CASE#__________________________________________________________
PACKAGE__________OF__________
5.
Complete an Evidence Submission Form. Be sure to take your time and thoroughly fill in all of
the necessary information. Sample forms are available to assist you in completing this form.
6.
Write or include a summary of the incident or scene being investigated. The length and
detail of the summary should be commensurate with the complexity and severity of the case.
7.
Transport your evidence and documentation to the lab. You must schedule an appointment
with Evidence Intake prior to transporting evidence to the laboratory.
8.
Testing Reports will be mailed and/or given to submitting agency at their next evidence delivery.
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Describing Your Evidence
When listing evidence on the submission form, it is not necessary to give lengthy descriptions or describe
secondary containers. The following is an example of how evidence should be listed on the submission
form:
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“One Ruger handgun”
“White powder (from John Doe)”
“Fingerprints of John Doe”
“Fired bullet”
“Discharged cartridge case from behind house.”
It is not necessary to list model numbers, serial numbers, and other miscellaneous information. The
purpose of an evidence submission form is to inventory what is in the package and (in some cases) from
whom or where it was recovered.
Laboratory Evidence Routing
Forensic science laboratories process evidence in a specific order. The following is the routing policy of
the laboratory:
“The sequence in which the laboratory processes evidence can have a significant impact
on the integrity of the evidence. Evidence submissions with multiple service requests
must be routed through the laboratory in the proper sequence. The following sequence
will be followed unless case specifics dictate otherwise:
1.
2.
3.
4.
5.
Trace Analysis / Flammables & Combustibles
Forensic Biology
Latent Fingerprints
Controlled Substances
Firearms/Toolmarks
It is the responsibility of each analyst to be aware of other forensic services requested for
a particular submission. By virtue of their expertise, analysts will be expected to assess
how and if a specific analysis may compromise the suitability of the evidence for analysis
by subsequent disciplines. When such circumstances are present, the analysts from the
corresponding sections of interest will confer and act accordingly. If the evidence is
associated with a death investigation or cases where the victim or suspect is known to be
a juvenile, the laboratory director must approve any routing changes.”
Selecting Your Packages
The packages or containers that are selected for evidence will often depend on the evidence itself.
Evidence packages fall under two broad categories: External Packaging and Secondary Packaging. An
external package is the outermost container upon which all of the necessary information will be written. A
secondary package is one or more that is sealed inside of the external package. An evidence
technician’s goal in selecting a suitable package for evidence is to protect the evidence from loss or
damage and to allow for a proper seal as listed in the next section.
Sealing Your Packages
The purpose of a seal is to accomplish the following:
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Prevent loss of evidence
Prevent cross-transfer of evidence or evidence samples
Prevent deleterious change or degradation resulting from exposure to air or ambient conditions
Render the package tamper evident making it impossible to access the interior of the package
without causing obvious damage to it
Identify the person who created the seal and the date it was sealed
If any of these objectives have not been met, then the seal is improper. A seal should be made with
tamper-indicating tape when possible, with the officer’s initials, badge number, and date written across
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the tape and onto the package itself. Seals such as those found on envelopes, which are made by the
manufacturer of the container, are considered sealed and need not be marked or over-sealed in any way.
It is vitally important that law enforcement officials be aware of how to properly package and seal their
evidence for submission to the laboratory.
Marking Your Packages
There are many different kinds of evidence packages and containers. Many that you will see on a daily
basis are pre-printed with fields to be filled out by the submitting agency. Not all packages, however,
have such fields. At a minimum, the following information should be marked on the external package
when submitted: Agency Name and Agency Complaint Number.
Refer to forensic disciplines in the table of contents for more specific evidence packaging procedures.
Submit Best Evidence First
In many cases, particularly the more complex ones, at-scene investigators may have a myriad of items to
collect for submission to the laboratory. The excerpt on the following page was paraphrased from the
book Mute Witnesses: Trace Evidence Analysis, by Max M. Houck, and should be kept in mind when
submitting evidence to the forensic science laboratory:
“Often, crime scene personnel in a desperate attempt not to make a mistake
nevertheless err on the side of caution and collect many, many items of evidence. Most
of these do nothing more than create a glut of evidence in the laboratory and a backlog of
cases for the examiner. No one can deny that thoroughness is the watchword for crime
scene processing but thoughtfulness is nearly as important. Blindly grabbing every item
of clothing from a suspect’s or victim’s closet with no regard as to why those items are
being collected does a disservice to the laboratory and, eventually, to the investigator as
well. Given the intense media coverage that can smother a breaking case, the fear of
later scrutiny and blame at not having collected every possible item of evidence can be
understood, if not appreciated. But fear is a poor justification. Reason, experience, and
case circumstances should dictate what is collected.”
An important point to grasp from this paragraph is the inherent problems that arise when items are
“blindly” collected and submitted to a forensic science lab. Investigators should know specifically why a
particular piece of evidence is of probative value and make attempts, either verbally or in writing, to
communicate this to the laboratory.
The submission of excessive amounts of evidence to a forensic science laboratory creates two
fundamental problems. First, the effort the scientist will have to make to keep numerous items organized
and protected may detract from his/her focus on how that evidence relates to the facts of the case.
Managing a pile of questionable items hinders the scientist’s ability to “reconstruct” how they may have
been involved in the crime, which is ultimately what investigators want to know. Second, the case will
take longer to work, delaying the reporting of results that may be time-sensitive, and generally bogging
down the lab in increasing backlogs.
Particularly in major cases, it is important to identify what evidence is most probative at a given time. The
DuPage County Forensic Science Center is prepared and equipped to report critical analytical findings
within hours, and sometimes minutes of submission. Often times, these early investigative leads prove
valuable in identifying or locating a suspect shortly after a crime is committed.
Controlled Substances
Description of the Science
Utilizing microscopical, instrumental, chemical and other techniques, unknown substances in various
forms including, but not limited to, plant material, powders, tablets/capsules, paper and liquids can be
analyzed for the presence of controlled substances and cannabis as defined under Illinois Chapter 720,
Acts 550 and 570.
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Special Considerations
Submissions for controlled substance analyses come in a wide range of sample types and sizes.
Packaging and submission procedures must be governed on a sample-by-sample basis.
Susceptibility to Contamination
Possible sources of contamination include the unintentional introduction of a controlled substance by
sample cross-contamination. This can result from careless handling or improper packaging.
Safety Hazards
Exposure to substances of unknown origin represents a significant health and safety hazard. This
exposure may be through ingestion, respiration, or absorption through direct contact with the skin or
mucous membranes.
Submission Restrictions
As part of the laboratory’s ongoing management of its case volume, it is common for the laboratory to
return evidence on cases that will no longer be adjudicated, particularly as a result of guilty pleas. The
purpose for such action is to clear our caseload so that our chemists can devote their time to cases being
addressed by the criminal justice system. Drug identification testing is not conducted on residues when
the surface has been subjected to field testing by police personnel. In addition, the laboratory will not
conduct analysis of evidence in cases limited to violations of local ordinance. Only cases involving
potential criminal charges qualify for laboratory testing.
The following submission policies apply to controlled substance cases:
1. The laboratory does not accept cases where there is no suspect.
2. Cannabis pipes will not be tested for drug paraphernalia charges.
3. Syringes and needles will not be accepted.
4. Drug identification testing is not conducted on residues when the surface has been subjected to
field testing by police personnel.
5. The laboratory will not conduct analysis of evidence in cases limited to violations of local ordinance.
Proper Packaging and Submission
The following guidelines should be adhered to whenever possible. If circumstances arise that cannot be
addressed by this list, contact the laboratory immediately.
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Please do not submit field test kits.
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Cannabis plants must be submitted in a dry state, packaged in paper or cardboard. If the plants are
growing when found, remove the plants from their containers and remove as much dirt as possible,
leaving the root system intact. A plant is not considered a plant unless the root system is attached.
Allow the plant to air dry before packaging.
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Liquid evidence should be submitted in a leak-proof container and should be kept refrigerated. If the
original container leaks when tipped, transfer the contents to a new container (jar, vial, etc.).

When liquids are submitted for controlled substance analysis, the entire amount must be submitted.
Liquids are not accepted for alcohol analysis.
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Please note on the submission form if the case is a garbage pull and, if so, mark it as biohazardous.
We will prioritize garbage pulls if they are being used to obtain a search warrant.
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Please note on the evidence and/or submission form, the location where each item was found and
which suspect it will be attributed to. It is also important to note if there was an item that was the
probable cause to search, etc.
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Advise the laboratory when submitting suspected PCP, as the solvent may be flammable.
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If the evidence is from a controlled buy please indicate if it was an informant buy (agency designation
A, B, C etc), or an agent controlled buy (agency designation 1,2,3 etc).
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Testing of pharmaceutical tablets and capsules will be limited to the highest schedule.
Explosives
Description of the Science
Utilizing the scientific principles of chemistry and microscopy, the laboratory is able to identify the
presence of explosive mixtures in submitted samples. Analytical data generated by instrumentation and
visual inspection is compared against known standards, allowing the forensic chemist to conclusively
identify the presence of explosive mixtures or residues.
Special Considerations
The laboratory routinely accepts suspected explosive powders from improvised explosive devices (IED’s)
such as pipe bombs, M-devices (i.e. M-80’s) and chemical reaction (pop bottle) bombs.
The laboratory will not accept primary explosives such as blasting caps. The safety of the officer during
transport, and the safety of laboratory personnel must be vigilantly protected.
The laboratory will also not accept commercially manufactured and military high explosives such as
Dynamite and plastic explosives, nor explosive residues from explosions suspected of being caused by
such devices. In explosion cases involving the analysis of these explosive residues, contact the Bureau of
Alcohol, Tobacco, and Firearms. For analysis of unexploded high explosives of military or commercial
origin, contact the Illinois State Police Forensic Science Center in Joliet or Chicago, Illinois.
It is noted that the majority of explosive devices encountered in this country, as of the time of this writing,
are improvised low explosives and samples of these types of devices are routinely submitted to the
DuPage County Forensic Science Center for analysis.
Susceptibility to Contamination
Possible sources of contamination include the unintentional introduction of explosive mixtures by sample
cross-contamination.
Safety Hazards
Exposure to substances of unknown origin represents a significant health and safety hazard. This
exposure may be through ingestion, respiration, or absorption through direct contact with the skin or
mucous membranes.
Explosives pose a significant safety hazard of their own. The instability of explosive mixtures can cause
an explosion. Some mixtures can be absorbed rapidly through the skin causing, in some cases, severe
headaches. Call the Sheriff’s radio room at 407-2400 to contact a member of our Hazardous Device and
Explosives Unit.
Proper Packaging and Submission
All explosive or hazardous devices must be rendered safe by a qualified technician prior to submission to
the laboratory.
After rendering the device safe, the bomb technician will provide the laboratory with a small
representative sample of explosive powder in a sealed glass vial for analysis.
The remains of exploded IEDs and surrounding solid materials suspected of containing explosive residue
should be collected in an unused metal can with a securing lid. The submission of soil / dirt should be
avoided.
The remains of exploded pop bottle bombs should be submitted in either a plastic evidence bag or if
fingerprint processing is requested, place the exploded pop bottle in a sealed gray epoxy lined paint can.
A portion of any remaining liquid should be submitted to the laboratory in a sealed glass vial preferably
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with a Teflon lined screw cap. This liquid is typically highly caustic / corrosive and extreme caution must
be used when handling such materials.
It is recommended that evidence submitted for explosive residue analysis be submitted ASAP to avoid
potential chemical degradation due to long-term storage.
Fibers
Description of the Science
Utilizing microscopical, instrumental, and chemical techniques, the laboratory is able to compare fibers of
unknown origin with known standards to determine the possibility of common source. Also, the type of
fiber, its color, and composition can be ascertained. The purpose of this type of analysis is to provide
associative evidence to investigators for the purpose of linking or excluding an individual as being present
at a scene or in contact with another person or item.
Special Considerations
Like other trace evidence examinations, fiber examinations are often time consuming due to the
preparatory steps that must be taken to ready the fibers for analysis. For homicide or other sensitive
cases, preliminary investigative information can be provided. In most cases, however, fiber examinations
are limited to comparisons of unknown or questioned fibers, with standard fibers whose origin is known.
Susceptibility to Contamination
Possible sources of contamination include the unintentional deposition of miscellaneous fibers on items to
be examined, such as clothing or bedding. This contamination can come from ambient surroundings, from
law enforcement personnel, or from sample to sample cross-contamination. Cross contamination of fibers
can be minimized at crime scenes with the routine use of clean, unused disposable garments such as,
caps, booties, gloves and hooded coveralls of known composition.
Safety Hazards
There are no specific safety hazards associated with this kind of evidence. Other hazards, however, may
exist warranting the exercise of universal precautions.
Proper Packaging and Submission
Loose fibers should be submitted in a sealed paper-fold and placed in envelopes or bags to prevent loss
or cross-transfer. Questioned fibers can be collected from large, or bulky item surfaces, not suitable for
submission to the laboratory, with transparent lifting tape. The laboratory currently uses Scotch brand 845
Book Tape that is 3 inches wide. Another good transparent lifting tape is Scotch brand 600 Transparent
Tape that is 2 inches wide. The tape rolls should always be stored in a clean re-sealable plastic bag when
not in use. Recent fiber and hair transfers can be collected and preserved by taping and lifting off of a
surface until the tape begins to lose some tackiness. The tape lift is then folded over itself so that the
tacky surfaces are protected form possible contamination. The folded tape lift should be no more that 5
inches in length and the tape should be evenly folded so that no adhesive surfaces are exposed. Tape
lifts can be stored in sealed envelopes. Tape lifts and all other packaging should clearly indicate the
location or person from which the sample was collected. Standards should be submitted in the form of a
piece of cloth or garment if available, packaged in an envelope or paper bag and marked accordingly.
Comments
Transfer of fibers between individuals or objects occurs constantly during the course of completely
legitimate business. The presence of fibers, absent standards for comparison, is of little or no value to an
investigation. Standards should always be submitted with questioned fiber evidence; however, it is
important that standards and questioned fibers be packaged separately (independently of each other).
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Fingerprints
Description of the Science
Utilizing visual, photographic, and chemical processing techniques, the laboratory is able to compare the
fingerprints of known individuals with latent fingerprints recovered from or developed at a crime scene.
The basis for the science of fingerprint examination is that friction-ridge patterns present on the human
fingers, palms of the hands, and bottoms of the feet are both persistent and unique to an individual.
Submission Restrictions
No evidence associated with a case in which there was no physical injury to a person and the total loss or
damage suffered by the victim is less than $500, or in multiple associated cases where the loss or
damage suffered by the victims is less than $1,500 will be accepted for latent print examination. There
may be exceptions; however, in such instances the laboratory must be contacted prior to submission.
Special Considerations
Fingerprints are primarily made of water and therefore are inherently fragile making them sensitive to
removal from contact and environmental conditions such as extreme temperatures.
Elimination Prints
It has been estimated that approximately 60% of all latent prints suitable for comparison are identified to
elimination prints, defined as record finger and/or palm prints for all individuals having legitimate
access to a crime scene or are known to have touched a particular item in question. This estimation
undoubtedly illustrates the importance of obtaining and submitting clearly and completely recorded
elimination prints. Furthermore, the State of Illinois requires elimination prints to be compared to latent
prints prior to all Automated Fingerprint Identification System (AFIS) searches. For these reasons it is
required that elimination prints be submitted with questioned evidence in latent print cases. This
thoroughness will save time and effort, particularly during the later stages of an investigation.
Susceptibility to Contamination
Contamination is caused by the unintentional deposition of fingerprints on items to be examined – often
by first responders or other law enforcement personnel.
Safety Hazards
There are no specific safety hazards associated with this kind of evidence. Other hazards, however, may
exist warranting the exercise of universal precautions.
Proper Packaging and Submission
Latent fingerprint evidence should always be packaged in paper or cardboard. Sealed plastic should
never be used. Also, secure the item within the package to minimize movement, which might wipe away
latent prints that are present. Items that are Superglue fumed prior to transport and submission are not
as sensitive to degradation.
Comments
The laboratory has witnessed an increase in the number of cases that require physical processing by our
scientists. Whenever possible, investigating agencies should process non-porous evidence (superglue
fuming and powdering) immediately after collection. Studies have shown that processing conducted by
the investigating agency immediately after collection increases the likelihood of developing comparable
prints by shortening the time that they are exposed to ambient conditions. Because it is time-consuming
for our scientists, we will prioritize cases for agencies that 1) take the initiative to process non-porous
evidence immediately after collection, and 2) submit latent lifts to the laboratory for comparison.
Firearms (Ballistics)
Description of the Science
Utilizing microscopical, visual, and chemical techniques, the laboratory is able to provide a wide range of
services with respect to firearms evidence. In its most basic form, firearm identification involves
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determining if a fired bullet or discharged cartridge case was or was not fired from a particular firearm.
Such conclusions are possible due to the microscopic imperfections left in the barrel and other
components of the firearm during the manufacturing process. The resulting pattern of striae and
impressions imparted to bullets and cartridge cases are unique to the gun that fired them.
Firearms examination offers various types of analysis and conclusions that can be offered. The following
examinations are performed on firearm evidence submitted to the laboratory:

Microscopical Comparative Analysis – This is commonly referred to as “ballistics” or the identification
of bullets and cartridge cases as being fired from a particular firearm.

Determine Type of Weapon (DTW) – Whenever fired bullets or cartridge cases are submitted to the
laboratory absent a suspect firearm, an examination (DTW) is performed to provide investigators with
makes of firearms that may have fired the submitted evidence.

Firearm Function Testing to include Routine Firearms Examination – This involves the examination of
the gun for operability as well as the amount of force required to pull the trigger. Routine firearms are
not associated with a shooting, but are submitted for function testing and to be compared against the
laboratory’s Unsolved Case File. See section below pertaining to the Sheriff's GRIP program.

Serial Number Restoration
Special Considerations
The value of the results rendered by a firearm examiner is often affected by the location or person from
which the examined evidence was recovered. Incident reports should always be submitted with firearm
evidence recovered from a crime scene.
Susceptibility to Contamination
Firearm evidence is often durable and not susceptible to environmental or ambient contamination.
Caution must be exercised, however, when removing bullets from walls or other structures. Toolmarks
imparted to the bullet during extraction can destroy the unique markings used for comparison purposes.
Safety Hazards
Firearms pose a significant safety hazard and should be treated accordingly. The possibility for an
accidental discharge warrants the exercise of extreme caution.
Firearm evidence often introduces a biological hazard, particularly in suicide cases or cases where bodily
fluids are deposited on the firearm. Bullets that pass through bodies are a biological risk, and often have
sharp jagged edges that can puncture the skin if handled carelessly.
Guns that are bloody or bear potentially biohazardous residue should be secured in a box with punch
holes and then further wrapped in a paper bag. This will prevent biological material from “falling” out of
the punch holes and contaminating surfaces coming in contact with packaged evidence.
Proper Packaging and Submission
Submittors must ensure that firearms are unloaded at the time of submission and that the barrel direction
is indicated on the package. If a submitting agency suspects that a firearm might be loaded, the
laboratory must be contacted prior to submission so that a qualified examiner is available to inspect the
evidence at the time of submission.
Evidence bullets should be packaged individually in small cardboard boxes, envelopes, or film canisters.
Bullets may be rinsed clean of bodily fluids to preserve the markings used for comparison; however, it is
not recommended brushes or abrasive materials be used to remove substances from the surfaces of
bullets as this may affect the integrity of toolmarks used during the comparison process.
Cartridge cases can all be packaged in a single container; however, multiple cartridge cases should be
packaged according to their location at a scene and marked accordingly. This often aids reconstructing
the crime scene, particularly when multiple shooters are involved.
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Comments
Firearm evidence is often an extension of the crime scene itself. Proper documentation of the condition
of a firearm (such as whether or not the hammer was cocked or safeties were engaged) should be
recorded by on-site personnel as needed.
Gun Recovery and Identification Program (GRIP)
For many years, the laboratory has accepted randomly seized firearms from submitting agencies that are
to be screened against the Unsolved Case File. The Unsolved Case File is a collection of fired evidence
samples (bullets and cartridge cases) that are associated with DuPage County shootings that remain
unsolved. From 1999 through 2004, the Forensic Science Center utilized the Integrated Ballistics
Identification System (IBIS) to computerize images of these samples and to screen submitted guns
against the database. While IBIS is a very valuable and effective tool in jurisdictions with rampant
firearm-related crime, after five years in DuPage County and no "hits," it was determined that a better
solution could be implemented that would provide agencies with information on a more frequent basis.
Hence, the GRIP program was born.
The trial phase of the GRIP program actually began in 2003, unbeknownst to our submitting agencies,
when laboratory scientists cataloged, classified, and photographed the evidence samples in the Unsolved
Case File. A formal screening protocol was established and immediate success was appreciated when
two unsolved shootings in DuPage County were linked to each other using the screening protocol.
Under the GRIP program, agencies submit firearms for function testing and screening against the
digitized and catalogued Unsolved Case File. Nonetheless, this laboratory recognizes that in some cases
there may still be a need to have fired evidence components screened through IBIS (i.e. known criminal
activity across state lines). For this reason, in 2012 our Unsolved Case File was entered into IBIS for
screening purposes. Likewise, during the submission of a firearm our submitting agencies can request
test fires be acquired and packaged externally for subsequent submission to another laboratory for IBIS
entry.
Flammables & Combustibles (Arson)
Description of the Science
Utilizing the scientific principles of chemistry, the laboratory is able to identify the presence of flammable
or combustible liquids in submitted samples. Analytical data generated by our instrumentation is
compared against known standards, allowing the forensic chemist to conclusively identify the presence of
accelerants that may indicate arson.
Special Considerations
Samples must be submitted as soon as possible due to the volatility of flammable liquids. Long term
storage of evidence cans containing clothing or fire debris evidence can result in chemical degradation of
potential flammable or combustible liquid residues. Evidence cans may also corrode rapidly depending
upon the corrosive nature of the fire debris present in the evidence can. This can lead to the production
of holes in the evidence can. The laboratory should be advised of how much time has passed between
sample collection and sample submission. Soil or dirt samples should be refrigerated or frozen to slow
microbial degradation of flammable liquids. When ever possible, submit an uncontaminated substrate
control sample. This is also known as a comparison sample. Examples include soil/dirt, home furnishings
such as draperies, and various construction materials such as molding, wood, floor tile, ceiling tile, roofing
materials and carpeting/padding. This is also important with substrate materials used by the fire
investigator to collect traces of flammable liquids such as a sponge or gauze pad.
Susceptibility to Contamination
Possible sources of contamination include the unintentional introduction of flammable liquids by sample
cross contamination. Never place latex or rubber gloves in containers with evidence sample. If you must
retain the gloves with the evidence, tape them to the exterior of the evidence can. If the evidence has
been repackaged from a plastic bag or other non-vapor tight packaging, make certain that this original
packaging material is not placed into the evidence can along with the evidence.
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If the presence of a particular type of flammable or combustible liquid is suspected based upon a fire
scene investigation, this information should be communicated on the laboratory evidence submission
form.
When receiving a new shipment of metal paint cans, each submitting agency can voluntarily submit one
new evidence can for quality control testing. Please contact the laboratory for further instructions.
Safety Hazards
Exposure to substances of unknown origin represents a significant health and safety hazard. This
exposure may be through ingestion, respiration, or absorption through direct contact with the skin or
mucous membranes. Flammable liquids represent an explosion hazard and should be treated
accordingly.
Proper Packaging and Submission
Submit fire debris evidence and clothing in unused paint cans to prevent loss of flammable liquid
evidence. The largest size can that can be accepted is a 5-gallon can. The use of paper bags or
cardboard boxes is unacceptable. Evidence cans must not be filled all the way to the top. They should be
filled no more that three quarters full, leaving an air space above the debris or clothing. Make certain that
you provide information regarding the type of evidence present in each evidence can and also provide the
recovery location. This information along with standard chain of custody information can be provided
directly on each evidence can.
Submittors must minimize potential hazards associated with flammable liquids and prevent loss of
evidence through the following:

Submit liquid samples in a secure unused container having a secure top, such as a glass vial or jar.
A glass vial with a Teflon lined screw cap is recommended. Do not submit liquid samples in bottles
with rubber eye droppers.

Submit no more than 2 milliliters of unknown liquid (in small vial) for analysis. Large cans containing
possible flammable liquid must not be submitted. Cans submitted for latent fingerprint processing
should be submitted empty and secured with a proper fitting lid or cap.

Be certain that the lid makes a strong seal around the entire can.
Comments
Clothing and shoe evidence that is submitted to the laboratory for flammable / combustible liquid analysis
must be packaged in a vapor-tight metal can in the same manner as fire debris evidence. Evidence cans
are commercially available in many sizes.
Forensic Biology & DNA
Description of the Science
Forensic Biology (FB) searches for the presence of hair and body fluids. FB currently provides
presumptive tests for blood, semen, and saliva, and one confirmatory test for semen. In the case of
contact with skin (see “contact DNA” below), the Forensic Biologist is limited to preparing the submitted
item for a DNA analyst to test.
Deoxyribonucleic acid (DNA) is a chemical that provides the instructions for a person’s physical
characteristics. A person is made of trillions of different kinds of cells. Each cell containing DNA has a
complete and identical copy of DNA in its nucleus (i.e., nuclear DNA). DNA is also found in other places
in the cell (for example, mitochondrial DNA). Taken as a whole, each person’s DNA is unique (with the
exception of identical twins). Forensic DNA only examines a few portions of the DNA, but because these
portions aren’t linked to each other, a specific combination of them can be highly discriminating. DNA
collected from a crime scene can either link a person to the evidence or eliminate them as the source of
DNA. DNA can also be used to show familial relationships. Using the DNA database (known as CODIS),
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DNA from crime scenes can be compared with the DNA of convicted offenders or with DNA left by the
same perpetrator at other crime scenes.
DNA results can be obtained from evidence that is decades old. However, several factors can affect the
DNA left at a crime scene, including environmental factors (e.g., dilution, sunlight, and bacteria). Not all
DNA evidence will result in useful DNA results, although results can usually be obtained when testing a
visible stain. Generally, there needs to be several cell’s worth of DNA to obtain useful DNA results.
Special Considerations
When transporting and storing evidence that may contain DNA, it is important to keep the evidence dry
and at room temperature (or lower). If evidence that may contain DNA is stored in plastic bags, metal
cans, Styrofoam, or glass, then it must be kept frozen without any thawing. Do not expose evidence to
direct sunlight and avoid places that may get hot, such as a police car without air conditioning.
Agencies are reminded of the statutory requirements of the Illinois Sexual Assault Evidence Submission
Act (Public Act 96-1011); specifically, the requirement that evidence submitted for analysis must include a
certification that the evidence is submitted in connection with a criminal investigation.
Susceptibility to Contamination
Due to the sensitivity of the tests used by our laboratory, extra care must be taken to prevent
contamination. Evidence can be contaminated when someone sneezes or coughs over the evidence or
touches his/her mouth, nose, or other part of the face and then touches the area that may contain the
DNA to be tested. It can even happen by leaning over the evidence because skin cells could be
unknowingly deposited on its surface. The DNA testing process will copy whatever DNA is present in the
sample; it cannot distinguish between the original DNA and DNA that was added later. However, the
DNA tests are semi-quantitative, so if there is a preponderance of DNA from one person, the DNA from
another person may not even be detectable. If a mixture is detected, it may be possible to attribute the
portion of results attributed to a particular person.
Safety Hazards
Biological evidence samples and materials may contain hazardous pathogens. Universal precautions
must be taken whenever blood or other body fluids are collected and submitted. All evidence that is
thought to contain body fluids must be labeled with a biohazard label.
Proper Packaging and Submission
Investigators and laboratory personnel should work together to determine the most probative pieces of
evidence and to establish priorities. The most useful information will be obtained when the analyst can:
 find blood or other body fluid with the victim’s DNA profile on the suspect, something in the
suspect’s possession, or something associated with the suspect
 find blood or other body fluid with the suspect’s DNA profile on the victim, something in the
victim’s possession, or something associated with the victim.
How to Collect Questioned Samples - When samples are small and easily transportable, such as a
cigarette butt or a t-shirt, they can be collected and packaged whole. In many instances, it is better for
the crime scene investigator to collect the stain via swabs or cuttings. The method chosen will vary
depending upon whether the surface upon which the stain has been deposited is absorbent or not. For an
item that is absorbent, such as a carpet, the best collection method may be to cut out the stained portion.
Non-porous surfaces, such as a glass window, are amenable to swabbing. Do not handle the stained
area directly. Wear gloves when collecting stains.
To collect dried stains, use distilled water to moisten a cotton swab (or thread, gauze, filter paper, or
cloth) and rub this across the stain. This may be followed by a dry swab, but if so, note which swab is the
wet swab and which is the dry swab. Make the stain as concentrated as possible on the swab, but be
sure to collect the entire stain. Air-dry wet stains at room temperature before packaging. Do not fan or
heat-dry stains. If multiple swabs of a single stain are collected, it is good practice to number the swabs
in the order they were collected. A control sample may be collected from a nearby area, but due to the
sensitivity of DNA and the semi-quantitative nature of DNA results, the laboratory does not typically test
controls.
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To collect a standard (a DNA sample witnessed to have come directly from a person, and used for the
purposes of comparing to DNA results from evidence), blood or saliva (i.e., buccal) samples may be
submitted. For buccal swabs, be sure to use a sterile swab. Do not let the subject eat, drink, or place
anything in their mouth, except for water, for approximately 15 minutes prior to collection. It may be
helpful to have the subject rinse their mouth with water before collecting the sample. Rub the inside of
either cheek a few times. It is not necessary or helpful to swab the subject’s tongue, teeth, throat or lips,
or to collect different areas of the mouth.
Items submitted for DNA analyses are categorized and prioritized as follows: (1) associative analysis, (2)
corroborative analysis, and (3) crime recreation. Analyses will not be conducted for the sole purpose of
crime-recreation when a suspect has been identified and case information provides no compelling
indication that additional suspects were involved. Visible stains will be screened and tested for DNA only
when the questioned contributor had no legitimate or innocent access to those surfaces.
The laboratory will strive to limit DNA testing to visible stains, residues, or materials. “Contact DNA” (or
touch DNA) that is not discovered through an observable residue will be tested when the surface upon
which the DNA is collected was in consistent or exclusive contact with the questioned contributor. For
contact DNA evidence, the laboratory may opt to defer the analysis pending submission of elimination
standards from emergency and police personnel who accessed the crime scene.
Glass
Description of the Science
Using microscopical, visual, and various physical measurement techniques, glass comparisons can
determine whether particles of glass could have originated from a particular source. Moreover, glass
fracture examinations can determine the direction and type of the breaking force and the sequencing of
shots where bullets have passed through the glass.
Special Considerations
Like other trace evidence examinations, glass examinations are often time consuming due to the
preparatory steps that must be taken to ready evidence for analysis. For homicide or other sensitive
cases, preliminary investigative information can be provided.
In most cases, however, glass
examinations are limited to comparisons of unknown or questioned fragments, with standard fragments
whose origin is known.
Susceptibility to Contamination
Possible sources of contamination include the unintentional deposition of miscellaneous glass particles
on items to be examined, such as clothing or bedding. It is imperative that glass standards and any
evidence containing potential questioned glass be packaged in such a manner to eliminate the possibility
of glass fragment cross contamination.
Safety Hazards
Glass fragments are often sharp and can puncture skin.
Proper Packaging and Submission
Submit samples of glass from each broken window or source in leak proof containers such as film
canisters or plastic pill bottles. Avoid using paper or glass containers if possible. When the location of
trace evidence is of importance, collect and package the evidence, noting its location.
Submit samples of laminated glass (such as a windshield) from each side of the laminate (entire pieces of
laminated glass are preferred). Label the samples INSIDE and OUTSIDE and package separately in leak
proof containers such as film canisters or plastic pill bottles. Avoid using paper or glass containers.
For glass fracture examinations, label the sides of the glass in the frame INSIDE and OUTSIDE. Label
the glass where it was removed in the frame such as TOP, BOTTOM, LEFT, and RIGHT. Submit all
glass pieces so that the pieces can be fitted together to identify the radial cracks near and at the point(s)
of impact and to increase the probability of matching edges. Pack all glass separately and securely to
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avoid shifting and breaking during transport. Secure the glass between sheets of plywood or sturdy
cardboard. Do not place any objects into the impact area.
Clothing evidence should be packaged in sealed unused paper bags. It is recommended that each article
of clothing and footwear should be packaged in a separate paper bag.
Hair
Description of the Science
Utilizing microscopical and visual techniques, hair examinations can determine whether hairs are animal
or human. Race, body area, method of removal, damage, and alteration (that is, bleaching or dyeing) can
be determined from human hair analysis. Examinations can associate a hair to a person on the basis of
microscopic characteristics in the hair but cannot provide absolute personal identification. A determination
of the species or family of an animal hair may be made by microscopical hair examinations.
Special Considerations
Like other trace evidence examinations, hair comparisons are often time consuming due to the
preparatory steps that must be taken to ready the hairs for analysis. For homicide or other sensitive
cases, preliminary investigative information can be provided. In most cases, however, hair examinations
are limited to comparisons of unknown or questioned hairs, with standard hairs whose origin is known. In
general, most comparisons are conducted using head or pubic hair samples.
Testing Hairs for DNA - The DuPage County Forensic Science Center currently has the capability to
perform nuclear DNA analysis on hairs; however, in order to perform this type of analysis, follicle tissue
should be present around the root of the hair. This is typically observed on hairs that have been forcefully
removed from the scalp. Nuclear DNA analysis is rarely successful on hair fragments (no root) or most
naturally shed hairs.
Another type of DNA analysis can also be performed on hair fragments or on hairs with no follicle tissue.
Known as mitochondrial DNA analysis, this type of DNA typing does not have the specificity of nuclear
DNA analysis since it involves only the maternal half of a person’s DNA. Currently the FBI laboratory and
a few private labs perform this type of analysis on selected hairs that have been screened
microscopically and are related to homicides or other violent crime investigations.
DNA analysis procedures are destructive to hair evidence. Because of those and other factors, the role
of DNA analysis in forensic hair examination will usually be as a second test used to confirm a
microscopical hair association and provide a probability of match determination. The microscopical
approach to hair examination will continue to be the primary procedure in forensic hair examination.
When DNA analysis is requested for hair evidence, questioned hairs will be microscopically evaluated for
suitable candidates to be analyzed for DNA.
Significance of Hair Evidence - Traditional microscopical comparison of questioned hairs from crime
scenes or other sources to known standards has been performed routinely with the aid of the comparison
microscope for nearly a century and involves the direct examination and comparison of class
characteristics present in the hairs. Hair evidence does not contain individual characteristics that would
permit personal identification. However, hair associations or eliminations can be obtained and these
findings may be significant as an investigative tool and are accepted in court.
Collecting Hair Standards - Standards containing numerous hairs are required for microscopical
comparisons so that a representative sample containing the range of characteristics for a particular
individual is available. This will help avoid a false elimination during the comparison process. Every effort
should be made to see that hair standards are collected as soon as possible relative to the occurrence.
Microscopical hair comparisons are typically limited to head and pubic hair comparisons. Hairs from the
other body areas are usually of little or no microscopical comparison value. Animal hair comparisons are
occasionally requested and can be useful for elimination purposes but have limited associative value.
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Head hair standards consist of a total of 50 to 100 hairs pulled from the top, sides, front, and back of the
head with thumb and forefinger. Pubic hair standards consist of a total of 25 to 50 hairs pulled from the
pubic mound. The hair standards should not be cut or pulled with forceps. Animal hair standards can be
obtained by vigorous combing or brushing of 500 or more hairs from the entire body with a clean unused
comb or brush. Hair standards should be placed into a clean paper fold that is placed into an envelope
and sealed.
It is noted that used combs or brushes containing hairs taken from a victim’s or suspect’s home does not
constitute a hair standard. Hairs found on these items are treated as questioned hairs.
In some instances, head hair standards may be difficult to obtain by pulling because the hair is short or
brittle. In these situations hair standards may be successfully obtained by a vigorous combing method.
This procedure must be conducted after thoroughly combing the hair to remove transfer evidence.
Separate clean, unused combs must be utilized for the collection of transfer evidence and hair standards
and each must be packaged separately with contents clearly described.
Under no circumstances should you substitute chest hair or other body hair for a head or pubic hair
standard. If difficulties persist in obtaining a proper hair standard, please contact the laboratory.
In order for hair comparison results to have probative value, it is necessary to obtain hair standards from
the suspects, victim, and all elimination candidates. Remember that the results of the microscopical
comparisons are based on similarities in both visual and microscopic class characteristics and the expert
cannot include or exclude a potential donor of a hair without having actual hair standards to examine.
Potential head or pubic hair transfer evidence must always be collected prior to the collection of hair
standards and are obtained with the aid of a new, unused comb. The comb and combings are placed into
a paper fold and sealed in an envelope. Modern Sexual Assault kits utilized in the state of Illinois provide
for the collection of head and pubic hair combings. No envelopes or instructions exist for the collection
of hair standards in these kits. Hair combings are considered questioned evidence and hair standards
must be obtained as soon as possible after a crime has been committed.
It should be pointed out that hair is a very common type of trace evidence that does not readily decay. It
has been examined forensically for nearly a century, along with other types of evidence, and in some
instances it may be the only physical evidence available in a criminal investigation. Its potential value
cannot be overemphasized.
Susceptibility to Contamination
Possible sources of contamination include the unintentional deposition of miscellaneous hairs on items to
be examined, such as clothing or bedding. This contamination can come from ambient surroundings,
from law enforcement personnel, or from sample to sample cross-contamination. Cross contamination of
hairs can be minimized at crime scenes with the routine use of clean, disposable garments such as, caps,
booties, latex gloves and hooded coveralls. It is imperative that standards and questioned hair be
packaged separately.
Safety Hazards
There are no specific safety risks associated with this kind of evidence. Other hazards, however, may
exist warranting the exercise of universal precautions.
Proper Packaging and Submission
Individual hairs should be placed in a paper fold and submitted an sealed envelopes or bags to prevent
loss or cross-transfer. Questioned hairs can be collected from large, or bulky item surfaces, not suitable
for submission to the laboratory, with transparent lifting tape. The laboratory currently uses Scotch brand
845 Book Tape that is 3 inches wide. Another good transparent lifting tape is Scotch brand 600
Transparent Tape that is 2 inches wide. The tape rolls should always be stored in a clean resealable
plastic bag when not in use. Recent hair and fiber transfers can be collected and preserved by taping and
lifting off of a surface until the tape begins to lose some tackiness. The tape lift is then folded over itself so
that the tacky surfaces are protected form possible contamination. The folded tape lift should be no more
that 5 inches in length and the tape should be evenly folded so that no adhesive surfaces are exposed.
Tape lifts can be stored in sealed envelopes. Tape lifts and all other packaging should clearly indicate the
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location or person from which the sample was collected. Garments or other cloth materials should be dry
and secured in paper or cardboard.
Intoxicating Compounds
Description of the Science
Utilizing the scientific principles of chemistry, the laboratory is able to analyze unknown liquids and gases
for the presence of intoxicating compounds as defined under Illinois Chapter 720, Act 690. Analytical data
generated by our instrumentation is compared against known standards, allowing the forensic chemist to
conclusively identify the presence of these substances. The use of compounds such as nitrous oxide,
toluene, acetone, and gasoline for their intoxicating effects is prohibited by law.
Special Considerations
Samples must be submitted as soon as possible due to the volatility of some compounds. The laboratory
should be advised of the how much time has passed between sample collection and sample submission.
Susceptibility to Contamination
Possible sources of contamination include the unintentional introduction of specific compounds by sample
cross-contamination.
Safety Hazards
Exposure to substances of unknown origin represents a significant health and safety hazard. This
exposure may be through ingestion, respiration, or absorption through direct contact with the skin or
mucous membranes.
Proper Packaging and Submission
Liquid samples should be submitted to the laboratory in a secured and sealed vial or bottle. The sample
should be kept refrigerated at all times. The sample size should be small (2ml vials are preferred).
Other items that are suspected to contain intoxicating compounds should be sealed and secured in vapor
tight containers, preferably arson cans. Please refer to the section on Flammables & Combustibles for
other packaging information.
Lamps and Filaments
Description of the Science
Lamp and filament examinations are relied upon to provide clarity to circumstances surrounding vehicular
accidents. By examining automotive lamps and the filaments contained within them, scientists can
determine if the filament was incandescent at the time the lamp was broken. This information may be
valuable in assigning responsibility to the operator of one of the vehicles.
Special Considerations
Lamp and filament evidence can be quite fragile requiring care in packaging, transport, and submission.
Vehicular information and accident sketches can also be useful to scientists examining the evidence.
Susceptibility to Contamination
Evidence can be contaminated if lamps broken during an accident are turned on afterward. This may
expose an intact filament to ambient air causing it to appear “on” during breakage when in fact it was
turned on after the accident.
Safety Hazards
Many lamps are under pressure and can shatter violently when broken. Sharp glass can puncture the
skin and cause bleeding. As with all types of evidence, universal precautions should be practiced.
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Proper Packaging and Submission
Automotive lamps and bulbs should be secured and protected from impact. Styrofoam cups are excellent
for securing bulbs. Protect items from impact and extreme temperatures.
Paint
Description of the Science
Utilizing microscopical, instrumental, and chemical techniques, crime laboratories are able to compare
paint samples to determine if they have a common origin. When two objects come into contact with each
other, such as two vehicles or a tool being used to pry open a door, paint can be exchanged. These paint
samples can then be compared to determine common source.
Special Considerations
As with all trace evidence, paint samples and objects suspected of bearing paint transfer should be
packaged in sealed containers, wraps or paper folds. Paper folds should then be placed into envelopes.
Do not package paint samples directly in envelopes or in plastic bags. These procedures will help prevent
cross transfer or loss of paint.
Paint chip standards must be taken from an area close to the damage but, not directly form the damaged
area. If no damage is visible, obtain paint standards from multiple locations. Paint chip standards must
also contain all layers down to the bare metal / substrate. Avoid obtaining paint samples by shaving or
scraping. If a cross-transfer has taken place between two vehicles, paint standards should be collected
from both vehicles following the same collection procedures. Loose questioned paint chips can be
collected with tweezers or scooped into a paper fold. Questioned paint transfer on clothing should not be
collected. In such cases, the entire garment should be packaged in a paper bag and be submitted for
paint comparisons.
Susceptibility to Contamination
Possible sources of contamination include sample- to- sample cross contamination. Tape lifts should
never be used to collect paint evidence. Adhesive residues can alter a paint sample by changing its
chemical properties. Use a new, clean scalpel blade or razor blade for each sample recovered
Safety Hazards
Exposure to substances of unknown origin represents a significant health and safety hazard. This
exposure may be through ingestion, respiration, or absorption through direct contact with the skin or
mucous membranes.
Proper Packaging and Submission
As mentioned above, package paint evidence to protect trace evidence from loss, cross-transfer or
deleterious change. Each paint sample should be separately packaged and marked with all relevant
information including the exact location that the paint was taken from and whether the sample is being
submitted as a standard or as a questioned paint sample and whether the sample was collected from the
suspect or victim vehicles. In some situations it may be necessary to submit a large object such as a
motor vehicle part. Contact the laboratory prior to submitting such evidence.
The International Forensic Automotive Paint Data Query (PDQ)
PDQ is a computerized automotive database that contains chemical and color information relating to
original automotive paints. This paint database was developed by the Royal Canadian Mounted Police in
the 1970’s and computerized in the 1990’s.
This tool could be useful in hit & run cases with no suspect vehicles. Analysis of paint evidence and a
search of the data base may provide make, model & year of suspect motor vehicles based on original
paint layers.
The Illinois State Police Lab in Chicago is now up and running with PDQ and will accept such cases for
testing. Paint evidence or clothing evidence taken from victims in hit & run cases with no suspect motor
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vehicles should be submitted directly to the Illinois State Police Forensic Science Center in Chicago for
paint testing and PDQ searches.
Shoe and Tire Impressions
Description of the Science
Shoeprint or tire tread impressions are routinely left at crime scenes. These impressions are retained on
surfaces in two-dimensional and three-dimensional forms. Almost all impressions, including partial
impressions, have value for forensic comparisons. The examination of detailed shoeprint and tire tread
impressions often results in the positive identification of the suspect’s shoe or tire from the suspect's
vehicle.
Special Considerations
No evidence associated with a case in which there was no physical injury to a person and the total loss or
damage suffered by the victim is less than $500, or in multiple associated cases where the loss or
damage suffered by the victims is less than $1,500 will be accepted for impression examination. There
may be exceptions; however, in such instances the laboratory must be contacted prior to submission.
Likewise, it is important to remember that criminals are aware of their fingerprints but seldom take
precautions to mask their footwear impressions. Suspect shoes must always be submitted for
comparison. Furthermore, shoe soles, if worn, will continue to change after the crime is committed and
therefore, time is of the essence.
Susceptibility to Contamination
Contamination is caused by the unintentional deposition of shoe or tire impressions on items to be
examined or ground bearing impressions to be examined.
Safety Hazards
There are no specific safety hazards associated with this kind of evidence. Other hazards, however, may
exist warranting the exercise of universal precautions.
Proper Packaging and Submission
Shoes and evidence should be dry prior to packaging. Also evidence should be packaged in a way that
minimizes damage from jolt or impact. Questioned footwear/tire impressions in the form of a cast should
be allowed to dry and no attempts should be made to clean the cast after recovery. Questioned
footwear/tire impressions in the form of an Electrostatic Dust Lift should be packaged in a shallow box
with the lift taped securely to the bottom of the box. Proper photographic techniques can permanently
record impressions on immovable objects. The photographs can then be used to conduct comparisons.
Comments
The findings resulting from a shoe or tire impression comparison should be considered with the
understanding that impressions can occur through completely legitimate means and do not necessarily
associate a person with criminal activity.
Toolmarks
Description of the Science
Utilizing visual and microscopical techniques, the laboratory is able to compare toolmarks left on an
object at a crime scene (i.e. door, window, ATM, vending machine, etc.) with a suspect tool to determine if
that tool made the recovered marks. Such examinations are possible with a very wide range of tool types
and materials that may have been marked. Physical Matching involves determining if two items were
once joined to form a single entity. It is commonly referred to as a fracture-match.
Special Considerations
Toolmark analyses and physical comparisons (fracture matching) are only conducted by this laboratory in
violent crimes or cases in which the loss or damage suffered by the victim, or multiple victims in
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associated cases, exceeds $20,000. There may be exceptions; however, in such instances the
laboratory must be contacted prior to submission. Incident reports, to include the location of persons from
which the suspect tools were recovered, are especially useful in toolmark analysis. Tools not recovered
from a suspect or his property, or tools whose owner is not known, often carry little investigative value
even if an identification is made. Many times, toolmark identifications are augmented by latent fingerprint
identifications for the purpose of developing a suspect.
Susceptibility to Contamination
Contamination is caused by the unintentional marking of objects bearing questioned toolmarks, and
unintentional damage imparted to the working surface of a suspect tool.
Safety Hazards
There are no specific safety hazards associated with this kind of evidence. Other hazards, however, may
exist warranting the exercise of universal precautions.
Proper Packaging and Submission
Suspect tools should be packaged so that the working surfaces or edges of the tool are protected from
impact or damage. Questioned toolmarks will be submitted either in the form of a cast, or on material
removed from another larger object to facilitate transport. Whenever possible, the actual questioned
toolmarks should be carefully cut out of the host object and transported to the laboratory. Casts are
perfectly acceptable for marks that cannot be removed; however, the time to perform the laboratory
toolmark examination will be lengthened.
Other Resources
FBI Laboratory - Quantico, Virginia
703-632-7690
Accidental Poison Identification
DuPage County Health Department:
(630) 682-7400
Cases involving possible intentional food or
beverage contamination
Illinois Department of Public Health:
(312) 793-4758 or (217) 782-4977
Poison Control Center: (800) 222-1222
SET Laboratories: (847) 537-9221
Contact Bijan-Saeedi
Toxicology and DUI Kits
Illinois State Police Forensic Science Center at
Chicago: (312) 433-8000
Contact Toxicology Unit
Questioned Document (Handwriting
Analysis)
Illinois State Police Forensic Science Center at
Springfield: (217) 782-4975N Rutledge SCLF
Springfield, IL 62702-4958
2013 Forensic Science Handbook
Forensic Dentistry / Bite mark examinations
John P. Kenney DDS
DuPage County Coroner’s Office
101 S. Washington Street
Park Ridge, Il 60068-4290
(847) 698-2088 Fax: (847) 698-2091
Forensic Entomology
Neal Haskell, PhD
425 Kannal Avenue
Rensselaer, IN 47978
(219) 866-7824 Fax: (219) 866-7628
Soil Comparisons
Skip Palenik - Microtrace
Elgin, Illinois
(847) 742-9909
Gunshot Residue Analysis
Illinois State Police Forensic Science Center at
Chicago: (312) 433-8000
Contact Trace/Microscopy Unit
International Forensic Automotive Paint Data
Query (PDQ)
Illinois State Police Forensic Science Center at
Chicago: (312) 433-8000
Contact Trace/Microscopy Unit
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