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WHILE
Lawrence Livermores national security accomplishments have
received much publicity over the years, one Laboratory organization
has gained such a stellar reputation among law enforcement, intelligence,
and emergency response agencies that it is cited by Tom Clancy in
his novel Shadow Watch (Berkley Books, 1999):
Ive requested
assistance from the Forensic Science Center in San Francisco. Its
at the Lawrence Livermore National Laboratory. I dont know
if youre familiar with them.
They did evidence
analysis on the Unabomber case, the Times Square and WTC bombings
in New York, probably hundreds of other investigations, Nimec
said. Uplinks had a relationship with them for years,
and Ive worked with them personally. The LLNLs the best
group of crime detection and national security experts in the business.
Founded in 1991, the Laboratorys
Forensic Science Center (FSC) offers a comprehensive range of analytical
expertise to counter terrorism, aid domestic law enforcement, and
verify compliance with international treaties and agreements. The
centers combination of human and technological resources has
made it among the best of its kind for collecting and analyzing
virtually any kind of evidence, some of it no larger than a few
billionths of a gram. Its resources, expertise, tools, and techniques
are applied to all kinds of cases, from the September 11 World Trade
Center attack to the spread of anthrax spores, from multiple homicides
to nuclear materials smuggling.
FSC has a staff of 15 personnel,
mostly chemists, with expertise in analytical chemistry, organic
chemistry, inorganic chemistry, nuclear chemistry, toxicology, pharmacology,
special coatings, and forensic instrument design and fabrication.
The center also draws upon the resources of experts in Livermores
Chemistry and Materials Science and Nonproliferation, Arms Control,
and International Security directorates.
The centers approach
to forensic analysis maximizes the information that can be obtained
from sometimes extremely small samples of explosives residue, dust
particles, hair strands, blood stains, radioactive isotopes, drugs,
chemicals, and clothing fibers. As Brian Andresen, until recently
FSC director, says, Were probing the lower limits of
detection for many types of compounds isolated during an investigation.
Even the tiniest quantities, says Andresen, are usually enough to
provide compelling evidence that holds up in court. The minuscule
amounts of oils remaining on fingerprints, for example, can tell
the general age of suspects, their diet, and whether they smoke.
In that respect, says Andresen, Everything someone does leaves
a chemical or biological signature that we can investigate.
Many forensic research projects
have required FSC personnel to develop new analytical tools, forensic
techniques for analyzing trace amounts of evidence, and unique sampling
procedures. Several new, portable instruments have been developed
that are capable of detailed analysis in the field. These tools
provide important advantages when dealing with substances that may
be unstable, perishable, or too toxic to bring back to the Laboratory.
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Heather
King and David Chambers demonstrate Livermores solid-phase
microextraction (SPME) sampling technique for identifying and
quantifying the chemical composition of physical evidence. |
Supporting
International Security
Andresen
notes that the term forensic science used to apply only
to the scientific analysis of evidence for civil or criminal law.
Increasingly, however, forensic analyses done at FSC are broadening
that definition to include support for monitoring or verifying compliance
with international treaties and agreements, particularly those involving
weapons of mass destruction, and for countering threats of terrorism.
For example, the center is contributing to the National Nuclear
Security Administrations (NNSAs) Chemical and Biological
National Security Program to develop and field advanced technologies
to better prepare for, detect, and respond to chemical or biological
incidents in the U.S.
In light of its demonstrated
capabilities to analyze minute specimens, FSC was selected by the
U.S. State Department in 2000 to support the Organization for the
Prohibition of Chemical Weapons (OPCW) as the second U.S. certification
laboratory. (The other facility is the Edgewood Chemical and Biological
Analytical Center in Maryland.)
OPCW, based in the Netherlands,
is responsible for implementing the Chemical Weapons Convention,
which bans the production, stockpiling, or use of such weapons as
nerve agents and blister agents. OPCW-designated laboratories test
samples collected by OPCW inspectors from sources around the world
to determine whether the samples contain chemical weapon agents,
their precursor chemicals, or decomposition products. The convention
stipulates that all samples must be analyzed at the two OPCW-designated
laboratories. Federal legislation requires that all samples taken
from a U.S. facility be tested in a U.S. laboratory that is OPCW-certified.
FSC has established a separate
chemical weapons analysis laboratory that is certified by the American
Association for Laboratory Accreditation. To date, no actual samples
have been officially collected from any site or analyzed at any
laboratory. FSC, however, has been required to analyze and identify
constituents of mock samples supplied by the OPCW as part of a series
of proficiency tests.
According to FSCs Armando
Alcaraz, Passing the tests is a very challenging task because
the samples might contain literally thousands of chemicals that
are linked to chemical weapons manufacturing. He notes that
the samples are sometimes spiked with certain materials to deliberately
try to throw the analysis teams off track. Like the test samples,
the real samples will be extremely dilute (that is, parts-per-million
level) so that they can be shipped commercially or sent through
the mail.
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Scientists
from the Forensic Science Center have miniaturized thin-layer
chromatography to make it suitable for field use. The portable
system includes appropriate reagents, glass plates, a digital
camera, and a notebook computer. |
Helping Law Enforcement
FSC
also assists law enforcement agencies with special needs that cannot
be handled by standard crime laboratories. Were not
in the business of routine police lab work, Andresen cautions.
However, for cases that are particularly difficult, FSC may be a
valuable resource capable of providing a conclusive analysis. In
this respect, law enforcement agencies benefit from Livermore technologies
that were developed initially to support counterterrorism efforts,
detect nuclear proliferation activities, and advance stockpile stewardship.
Under the 1998 Partnership
for a Safer America memorandum of understanding between the
Department of Energy and the departments of Justice, Commerce, and
Treasury, the center provides law enforcement agencies such as the
Federal Bureau of Investigation (FBI), the U.S. Customs Service,
and the Bureau of Alcohol, Tobacco, and Firearms with new crime-fighting
technologies. This agreement provides a framework for formal working
relationships to facilitate the transfer of DOE technology and technical
expertise to law enforcement.
FSC deputy director Pat
Grant notes that supporting law enforcement increases the centers
expertise and shortens the turnaround times for sample analysis.
Anytime we analyze questioned samples important to a real-world
investigation, we are honing our skills. Its a much more interesting
and stimulating experience than participating in an exercise.
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The
portable thin-layer chromatography (TLC) system separates compounds
as they move up a glass plate placed in a small solvent reservoir.
Based on the distance the compounds travel, together with their
color and intensity, a computer identifies the compounds and
their relative concentrations. Above is a typical TLC analysis
done to detect propellant instabilities by measuring the amount
of stabilizer compounds. |
Shrinking
Instruments
Some of the centers
most enduring accomplishments are new tools it has developed for
intelligence, law enforcement, and health professionals working
in the field. These compact, battery-powered tools provide mobile
chemistry laboratories. Because they eliminate the need to ship
samples back to a standard laboratory for analysis, the portable
technologies greatly speed decision making.
For example, FSC scientists
have miniaturized and modernized thin-layer chromatography (TLC),
a well-established laboratory procedure that identifies compounds
belonging to the same general chemical class. FSC chemists made
TLC technology suitable for field use with a portable system that
fits inside a suitcase and weighs about 23 kilograms. Although the
portable system uses minimal equipment and chemical reagents, it
is highly specific and sensitive. The kits can be used to analyze
two sets of samples simultaneously, with each set containing about
10 samples. Depending on the compounds being analyzed for, the entire
process takes 10 to 20 minutes to complete.
TLC works by separating compounds
over the distance they move up a glass plate. Tiny amounts of samples
are placed just above the bottom edge of a TLC plate, the plate
is placed in a small solvent reservoir, and the solvent moves up
the plate by capillary action. A commercial digital camera captures
the resulting patterns of dark spots that develop, which are analyzed
on a notebook computer using a software program originally developed
for the analysis of DNA. Based on the distance the samples have
traveled, together with their color and intensity, the computer
program identifies the compounds and their relative concentrations.
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Forensic
Science Center chemist Del Eckels uses the 28-kilogram portable
gas chromatographmass spectrometer that fits inside a
wheeled suitcase. The portable unit, comparable in sensitivity
and selectivity to much larger and heavier units, permits fast
on-the-scene chemical analysis. |
The centers portable
TLC kits are tailored to detect chemicals indicative of chemical
weapons, high explosives, propellant stabilizers, or illegal drugs.
Each specialized kit includes solvents and developing reagents that
are specific to the compounds of interest.
The TLC system was originally
developed for the U.S. Army to quickly detect propellant instabilities
within the nations munition storage depots. Propellants (especially
high explosives) require stabilizers to prevent them from spontaneously
igniting. Because stabilizers are depleted by long exposure to environmental
conditions, the Army needed a way to quickly determine the safety
of large numbers of munitions. The centers TLC system requires
only 50-milligram samples of explosive, instead of the gram quantities
typically required by other methods, and 15 minutes for each group
of 20 samples, allowing many more samples to be analyzed and at
much lower cost than is possible using traditional methods. Army
personnel without a degree or extensive training in chemistry can
do this work, says FSC chemist Jeff Haas.
Over a few days in 1998,
the portable system successfully characterized the contents of more
than 1,200 unearthed mortar rounds discovered in a shallow excavation
site at an Army base in Massachusetts. (See S&TR, December
1998, Forensic
Science Sleuthing.) The system is now deployed at several other
Army facilities as well as by National Guard units.
The system is also used in
instances where analysis speed is essential. In light of repeated
success by a variety of users, the center is transferring the portable
TLC technology to private industry for commercialization and widespread
availability to federal and state law enforcement, customs, and
environmental agencies.
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The
imaging laser-ablation mass spectrometer combines a laser for
vaporizing extremely small amounts of material, an ion trap
time-of-flight mass spectrometer for analysis, and a high-powered
microscope for viewing. |
Advanced
Tools for Field Use
While TLC is effective for
identifying classes of chemicals that are specifically targeted,
the task of completely characterizing samples in the field requires
a more sophisticated instrument such as the gas chromatographmass
spectrometer (GCMS). An essential tool in every major analytical
laboratory, a GCMS can detect ultratrace quantities of organic
compounds weighing a billionth of a gram or less. The gas chromatograph
first slowly heats a sample to about 250°C. As the samples
volatile constituents travel down a long capillary column, they
separate according to their vapor pressures and chemical affinities.
As they flow into the mass spectrometer, the compounds are bombarded
with an electron beam that fragments molecules into ions that constitute
a unique fingerprint of that compound for positive identification.
FSC staff scientists have
shrunk the standard 114-kilogram laboratory GCMS to about
28 kilograms; it now fits inside a wheeled suitcase. The self-contained
portable device, comparable in sensitivity and selectivity to a
standard unit, contains a power generator, vacuum pumps, and laptop
computer. The result is an instrument that significantly improves
on-scene investigation and evidence collection.
Because of its ability to
analyze samples to parts-per-billion sensitivity within 15 minutes,
this portable GCMS can be used to support nonproliferation
activities, incident response, and law enforcement investigations.
For example, the instrument can precisely identify compounds indicative
of the manufacture of chemical warfare agents and illicit drugs.
The instrument is currently being manufactured under license to
industry.
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The
imaging laser-ablation mass spectrometer allows an investigator
to walk down a hair shaft by drilling consecutive
holes with the laser on the same hair and analyzing each to
obtain a volatile sample for a history of activities such as
drug use or exposure to chemical weapon compounds. |
Identification
with Lasers
Although many tools used
by FSC personnel depend on analyzing tiny amounts of chemicals that
are found in a vapor phase above a liquid or some solid materials,
most solid objects, such as human hair or clothing, do not have
a significant vapor pressure and thus do not lend themselves easily
to GCMS analysis. However, center personnel can vaporize these
solid samples with an extremely fine laser beam to generate wisps
of product that contain identifying compounds.
The technology is called
imaging laser-ablation mass spectroscopy. The process combines a
laser for vaporizing extremely small amounts of material, an ion
trap and time-of-flight mass spectrometer for analysis, and a high-powered
microscope for viewing. In this way, forensic scientists can collect
and rapidly identify suspect chemicals.
The process can be used on
almost any solid materialdirt, pieces of glass, paint chips,
clothing fibers, strands of hair. The samples are placed inside
an ion trap mass spectrometer, irradiated with a laser, and identified
within a few minutes by the mass spectrometer. The process allows
an investigator to walk down a hair shaft by drilling
consecutive holes on the same hair with the laser and analyzing
each volatile sample. Because hair grows at a standard rate,
the results can reveal a history of drug use or exposure to compounds
used in biological or chemical weapons manufacturing, says
FSC chemist Greg Klunder. He points out that the method could also
be applied to samples of clothing or soil sticking to the shoes
of someone suspected of developing chemical weapons.
A similar instrument still
under development is capable of detecting chemicals in air and is
well suited for high-speed aircraft sampling of exhaust smoke from
chemical facilities. Potential applications include identifying
hazardous spills, monitoring industrial stacks for certain compounds,
and surveying the environment from a remote location to detect chemical
releases from a suspect facility.
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The
Forensic Science Centers solid-phase microextraction (SPME)
collection kits use optical fibers as chemical dipsticks
and (inset) rugged aluminum transport tubes for safe and efficient
sampling. The technique has revolutionized collecting evidence
in the field. |
Wands
of Collection
One of the centers
most important developments has been the solid-phase microextraction
(SPME) collection kits that use optical fibers as chemical
dipsticks for safe and efficient sampling. The technique
has revolutionized the collection of forensic samples in the field,
says FSC chemist Pete Nunes.
The technology uses commercial
hair-size (100-micrometer-thick) fibers to capture organic vapors.
The fiber, residing inside a syringe, is coated with a chemical
polymer that, when exposed to the ambient environment for a suitable
amount of time, can collect thousands of different compounds by
acting as a chemical sponge. The polymer coatings are specific for
different types of compounds such as chemical warfare agents, high
explosives, or illegal drugs.
The collection technique
requires no solvents, sample workup, or additional equipment typically
associated with obtaining evidence. The fibers can be inserted directly
into a portable or stationary GCMS for immediate analysis.
Nunes says that because the
fibers are fragile, they had never been taken into the field. To
overcome their fragility, an FSC team developed rugged aluminum
transport tubes, with each tube securing one syringe and fiber.
A group of five tubes is contained in each kit. The hermetically
sealed tubes prevent any possibility of cross-contamination and
support chain-of-custody requirements. A sampling port in the bottom
of the tube permits assaying the contents in a glove box before
the tube is actually opened.
SPME sampling is being put
to good use by FSC weapons scientist David Chambers to monitor nuclear
weapon warheads safely. This activity is part of the NNSAs
Stockpile Stewardship Program to maintain the safety and reliability
of the nations nuclear stockpile.
Chambers uses SPMEs
coated fibers to collect volatile and semivolatile molecules that
are formed or outgassed from the nuclear and thermal breakdown of
organic polymers and high explosives. Signs of outgassing can indicate
problems such as corroded metal parts that need to be replaced.
By monitoring for the presence of these chemical vapors, scientists
are alerted to problems that may be developing inside the weapon.
The center has provided the
FBI and other agencies with SPME field kits for the safe and rapid
collection of chemical warfare agents. The kits are equally well
suited for drug detection and arson investigations. FSC has also
developed a new SPME transport tube that is smaller and lighter
so that it can fit inside a shirt pocket. Both versions are being
licensed to industry for sale to government agencies.
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This
solid-phase microextraction device is used to collect molecules
that are formed or outgassed from the nuclear and thermal breakdown
of organic polymers and high explosives contained in nuclear
warheads. Signs of outgassing can indicate problems with parts
that need to be replaced. |
Center
Plays Role in Famous Law Enforcement Cases
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The Forensic Science Center (FSC) has played a pivotal
role in several well-publicized criminal investigations.
For example, FSC examined the composition and structure
of tiny bomb fragments containing trace metal and chemical
residues in the Unabomber case.
The center provided
analysis and testimony leading to the conviction of
Fremont, California, bomber Rodney Blach, a former Chicago
Police Department forensic investigator. Blach was convicted
of planting bombs during 1998 at the homes of the police
chief, a city council member, and others. Former FSC
Director Brian Andresen helped investigators from the
federal Bureau of Alcohol, Tobacco and Firearms (ATF)
to reconstruct what Tom Rogers, assistant district attorney,
characterized as the largest as well as the most
electronically sophisticated domestic pipe bombs the
ATF had ever encountered. Rogers said, The
electronic aspects of the devices were beyond the expertise
of anyone at
the ATF.
FSC supported
the Democratic National Convention in 2000 by providing
a mobile forensic laboratory for the Los Angeles County
Sheriffs Terrorist Early Warning Group. The center
was also instrumental in interpreting factors surrounding
the death of Gloria Ramirez, who made several hospital
emergency room personnel violently ill in a well-publicized
Southern California case.
FSC helped prosecutors
in Glendale, California, rearrest Efren Saldivar, the
self-proclaimed Angel of Death and alleged killer of
many terminally ill hospital patients. FSC scientists
performed toxicology analyses on exhumed tissues from
20 patients. They didnt expect to find anything.
However, with the help of completely new techniques,
including sample collection procedures developed by
the center, they were able to identify the drug Pavulon
in the bodies of six of the deceased patients. The rearrest
of Saldivar was based primarily on the centers
findings.
Identifying
Bullet Fragments
FSC came to the
aid of Kings County, California, authorities who were
stymied by an execution-style triple homicide. The evidence
included a variety of bullet fragments but no weapons.
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Investigators
found corroded, expended casings scattered around the
grounds where the suspects lived. FSC personnel led by
Rick Randich chemically treated the casings to remove
corrosion and then used optical and scanning electron
microscopes to match the crime-scene evidence with residence
specimens. The staff published its restoration methods
as an aid to other agencies.
The center analyzed
debris from an explosion that killed a scientist during
a 1992 cold fusion experiment at SRI International in
Palo Alto, California. In testing the explosion debris,
FSC chemists discovered a trace amount of oil in the interior
of the SRI electrochemical cell. They determined that
a likely source of this oil was lubricating fluid that
remained from machining the metal cell components. They
concluded that the high-pressure oxygen atmosphere of
the electrochemical cell possibly created the potential
for an explosive reaction with the oil.
Many FSC investigations
involve identifying unknown substances. One specimen brought
to the center was a suspicious green liquid uncovered
by the Federal Bureau of Investigation (FBI) during a
search of a stolen cache of weapons. The container of
the liquid was labeled poison and gave a dilution
formula for use. FSC chemists analyzed the solution for
chemical warfare agents but finally identified it as a
concentrated cleaning agent.
Another extraordinary
analysis centered on a shipment of white crystals in ampoules
from China that was thought to be heroin. The powder was
interdicted by the U.S. Customs Service and subsequently
investigated by the FBI. FSC analyses identified the material
as tetrodotoxin, a deadly marine neurotoxin derived from
puffer fish. The definite identification of tetrodotoxin
was a real success story for the center, says Andresen.
In the past several
months, FSC has been helping authorities to identify samples
of substances suspected of being anthrax. Several of the
specimens brought to the center by law enforcement officials
were from the local community, while others were from
locations at the Laboratory. None was found to be real
anthrax; instead, the powders were determined to be food
materials, dust, dirt, cell culture medium, and powdered
paper. |
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Always
On Call
Although the Forensic Science
Center was highlighted in a Tom Clancy novel, it is not fiction.
It is a rich resource for the national security and intelligence
communities and has proved itself a valuable ally to federal and
state agencies alike. Just as they have for the past 10 years, FSC
personnel will be on call for the next case and the next sample.
—Arnie Heller
Key Words: anthrax,
Chemical and Biological National Security Program, Forensic Science
Center (FSC), gas chromatographmass spectrometer (GCMS),
laser-ablation mass spectroscopy, Organization for the Prohibition
of Chemical Weapons (OPCW), solid-phase microextraction (SPME),
stockpile stewardship, thin-layer chromatography (TLC).
For further
information, contact Brian Andresen (925) 422-0903 (andresen1@llnl.gov).
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