Caught, After the Act:
How Crime Solvers Use Scientific
Sleuthing to Stay Hot on the Trail of Wildlife Criminals
by Terry Dunn
In an ideal world, a wildlife criminal would be caught with his victim in one hand and a gun in the other. In the real world, criminals are sometimes snagged with the proverbial blood on their hands, but more often investigators find a few scraps of evidence and suspects who are intent on covering their tracks. When the only thing a wildlife criminal leaves behind is a drop of blood, a feather, or a few bones, scientists must step in to piece the story together.
In criminal cases involving people, police enlist the help of witnesses, DNA analysis, ballistic tests, and various other methods to narrow their search for a suspect. These same techniques are available to those who crack wildlife cases, but investigators sometimes have the added complication of first identifying the victims’ species.
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Confiscated animal products, including tusks, tortoise shells, and stuffed birds, at the U.S. Fish and Wildlife National Forensics Lab. (USFWS National Forensics Lab) |
Take the case of Dennis Steinbrech, an Iowa man who imported the skull of a brown hyena (Parahyaena brunnea), an endangered species, from Zimbabwe. He killed the hyena, as well as a nursing female leopard (Panthera pardus), in 1998 while on a safari trip. Although he was advised to discard the carcass rather than risk being caught with a protected species, he chose to send it home. He had an African taxidermist clean the skull and toss the telltale hide into an alligator pool. The taxidermist also labeled the skull as that of a common spotted hyena (Crocuta crocuta), which is not protected, on the import declaration form, and the skull slipped through customs uneventfully. But, rather than keep quiet, Steinbrech flaunted photos and boasted about his exploits in an Iowa bar. Someone overheard the conversation, reported him, and wildlife agents seized the skull. A mammalogist clinched the case by comparing the skull to that of a series of hyena skulls and concluding it was the skull of a brown hyena.
Discriminating between two closely related species by scrutinizing their skulls is difficult enough. Many times there is much less to go on. That was the situation in 2002 when a gruesome discovery was made in New Mexico’s Lincoln National Forest. It was in the midst of an early fire season when lightening, careless campers, and arsonists touched off numerous blazes. In the ashes of one arson fire, investigators found the badly burned carcass of a headless mule deer (Odocoileus hemionus). Using DNA analysis, scientists were eventually able to identify the individual animal and tie its remains to a suspect.
It’s no surprise that wildlife criminals go to great lengths to cover up their crimes. For wildlife criminals involved in the trade of wildlife parts, the profits can be lucrative and the punishment can be costly. In another interesting case, Alfred Yazback, the owner of a New York caviar company, found creative ways to profit from the reputation of Russian caviar.
He sold roe of American paddlefish (Polyodon spathula), a protected species from the Tennessee and Mississippi Rivers, in falsely labeled containers. The scam was uncovered when special agents in the Baltimore office of the U.S. Fish & Wildlife Service found a gourmet grocery in Rockville, Maryland, selling “Russian” Sevruga caviar for an unusually low price. Samples were purchased and, using DNA testing, scientists discovered that the caviar was from American paddlefish.
He also knowingly purchased smuggled Russian caviar to fill orders for Maryland gourmet markets. Although the caviar customers thought they were getting a good deal, they had no way of knowing that some of the black-market Russian caviar was shipped in unrefrigerated suitcases. To disguise the spoiled caviar, it was defrosted, washed with salt water, covered in walnut or hazelnut oil, partially pasteurized, then sold.
First Steps
When taxonomic experts at a museum or university receive
an unidentified specimen, they usually work with an
intact body and a country of origin. This means they
usually can identify an unknown specimen using standard
taxonomic keys. Wildlife forensic scientists aren’t
so lucky. They receive body parts or wildlife products
such as ivory carvings, leather goods, or Asian medicinals,
and frequently the country of origin is intentionally
concealed. Achieving an airtight case in court—linking
the suspect, the victim, and the crime scene—takes
a specialized, experienced team of scientists and some
amazing tools.
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Ivory is carved into cane handles and other ornaments. (USFWS National Forensics Lab) |
Many of these scientists work at the National Fish and Wildlife Forensics Laboratory in Ashland, Oregon. It was established in 1989 when it became obvious to special agents with the U.S. Fish & Wildlife Service that relying on museum and university scientists for forensic work wasn’t enough to keep up with the caseload. The lab is staffed by scientists recruited from universities and museums, as well as experts lured from police departments and human forensic laboratories. Because the lab was the first of its kind, the field of wildlife forensics was literally created as cases flowed in. And flow in they did.
According to the laboratory’s director, Ken Goddard, “To date, we’ve worked approximately 11,000 cases. One case may consist of a single feather or several hundred tissue or caviar samples.” The lab serves several law-enforcement agencies. “Right now, about 65 percent of our casework comes from our own federal agents and inspectors, about 30 percent comes from the 50 state fish and game agencies, and the remaining five come from international wildlife law enforcement agencies,” explains Goddard. Many of the federal and state cases also have international ties, however.
The morphology section of the forensics lab has specialists in mammals, birds, and reptiles, as well as a collection of feathers, bones, and fur samples from species around the world. There are thousands of whole carcasses or large-part specimens in their collections, which can help them distinguish between closely related species. The lab also has something in the neighborhood of 30,000 tissue specimens in its ultra-freezers.
When the hyena skull came to the lab, scientists relied on these collections to conclude that the skull was from a brown hyena. Bonnie Yates, the lab’s morphology section chief who identified the skull, explains the process like this, “I use direct visual comparison of the questioned skull with a series of skulls of known species and their representative skull measurements.” According to Yates, “Years of experience have taught me which characteristics are most robust in their ability to distinguish closely related species and which may be variable because of sexual dimorphism or individual development.” When the lab doesn’t have the appropriate specimens for comparison, it contacts other institutions, such as museums, to get the information that’s needed.
Steinbrech, the Iowa hunter, was eventually convicted of violating the Lacey Act, a federal wildlife law that prohibits the importation of protected animals and their parts. He was fined $10,000 and sentenced to 60 days in prison and three years’ probation. His hunting privileges have been revoked worldwide for the duration of his probation and the eavesdropper in the Iowa bar received a handsome reward from Lacey Act funds.
Certainly the scam turned out to be costly to the hunter, but it was also costly for the brown hyena population. The owners of the African ranch where the hyena was shot had never seen a brown hyena on their property and the Zimbabwe government believes there are only about 150 brown hyenas left in the country.
Back at the National Fish and Wildlife Forensics Laboratory, the morphology section also deals with a lot of feathers—the most commonly traded bird part because they are used for decoration and for ceremonial purposes. The job of identification can be no small task. The feathers of many species differ between the sexes and change with age and with the seasons. Not only that, there are nearly 8,700 species of birds.
The lab’s bird experts start by determining from which part of the body a feather originates: Stiff long feathers are more likely to be from wings and tails; soft feathers are typically from the body. By noting the size of the feather, then the color pattern, scientists can narrow it down to a group of birds. Once the group is identified, the feather can be compared to those of other birds in that group until a species match is found.
Big Crimes, Small Evidence
When the animal evidence is not substantial enough to
identify it through morphology, many other techniques
can be used. For instance, to determine what type of
animal a sample is from, scientists can start with a
technique called immunodiffusion. A blood sample is
“challenged” with antibodies to learn what
family the animal belongs to. From there, other techniques
are used to figure out the species, and in some cases,
the individual.
A quick way to identify a species is by testing the hemoglobin in tissue or blood samples. The test takes only five or ten minutes and looks at gene markers of the hemoglobin chains. Using an instrument with a mouthful of a name (the matrix-assisted laser desorption ionization time-of-flight mass spectrometer, or MALDI for short), hemoglobin molecules are mixed with an organic compound that helps with the analysis. The sample is then blasted with a laser beam that sends the molecules into flight. Because the time a molecule flies depends on its weight, and the molecular weight can be characteristic of a particular species, the scientist can determine what species the sample is from most of the time. About 12 percent of the time, the MALDI technique must be verified by another test, usually DNA analysis. Regardless, the species identification process has been sped up tremendously in the two years that the lab has used MALDI.
For those stubborn species identifications, DNA can be extracted from the mitochondria (the tiny “powerhouse” within each cell), then sequenced and compared to species in a gene bank. This is the classic “DNA fingerprinting” technique used in some human forensic cases. The drawback? “We can only do fingerprinting for five taxa,” according to Ed Espinoza, the deputy laboratory director and a forensic scientist at the lab. The taxa include wolves, elk, moose, mule deer, and bears (just black bears and polar bears).
Unlike human DNA fingerprinting, “In wildlife cases, we are hard up. Sample sizes are much smaller,” explains Espinoza. Sample sizes are particularly small for endangered species. With endangered populations of fewer than 4,000 individuals, it is difficult to know which DNA characteristics are “standard” and which are unique to that individual. When some members of a small population are in zoos, it becomes even more challenging. “Zoo samples are not representative of populations (in the wild),” says Espinoza. Basically, the more endangered, the less likely an individual can be distinguished from the rest of the population.
Since forensic scientists frequently need to identify small, degraded samples, researchers around the world are working to boost the number of species that can be identified using mitochondrial DNA. In India, scientists are using a slightly altered technique and a different section of mitochondrial DNA to add to the growing database. In a recently published study, Indian researchers at the Centre for Cellular and Molecular Biology were able to identify 221 animals to the genus and species levels, including 67 animals that are listed as endangered or threatened in that country.
To go from species identification to identifying an individual animal, scientists can use something called short tandem repeats, or STR. Within the DNA strands of each animal in a particular species, there are large sections that are identical and rarely change. There are also short, repeated sequences interspersed within these more stable sections that vary from individual to individual. Some individuals may repeat these sequences only four times. Others may contain 22 repeats of the sequence. By comparing these sections from two or more samples, scientists can tell whether or not the samples are from the same individual animal. For STR tests, scientists extract DNA from a whole cell or cells rather than extracting DNA solely from the mitochondria.
In the case of the charred mule deer skeleton from New Mexico, scientists cracked open the spine and extracted tissue from the spinal column. By using STRs, they were able to develop a genetic profile of that individual deer. When a suspect was found in the arson case, federal agents searched his home and confiscated the skullcaps and antlers from three deer heads. One of them turned out to be a genetic match to the charred body. The suspect pled guilty and has been sentenced to two years in prison for the arson-related charges.
In addition to being asked to identify species and
individual animals, forensic scientists must often answer
questions about sex, parentage, the number of individuals
in a sample, and the time of death (although that can’t
be determined on trophy mounts and frozen
carcasses). The roe in the caviar case was identified
using mitochondrial DNA, but scientists at the lab were
also able to estimate how many fish may have been killed.
Between the 534 pounds of roe the suspect sold and the
4,000 pounds he planned to sell, up to 170,025 fish
may have been killed.
Teasing out a cause of death is another important area of wildlife forensics. Obviously, the animals dying of natural causes or even at the paws or teeth of a predator need to be ruled out first. Examining a carcass for evidence of bullet wounds, knife wounds, trap wounds, poisoning, and electrocution is the job of the pathologists. Pathologists perform necropsies (animal autopsies), and use powerful microscopes, X-rays, and photography to get the information and documentation they need to determine how an animal died and to make a strong case in court.
Criminologists are responsible for analyzing other types of evidence that might be relevant to a wildlife crime. Matching firearms to bullets, tires to tire tracks, shoes to footprints, paint chips to vehicles, fibers to clothing, fingerprints to a person, and poisons to a bottle in a suspect’s garage are also important. More traditional chemists and ballistics experts take on these tasks. Their methods are as varied as the puzzles they face. Mass spectrometers are used to decipher the chemical makeup of pesticides and other poisons. To match a bullet found in an animal to a bullet shot from a particular gun, striations on the bullet’s surface are looked at through a microscope. Microscopes are also used to see if a fiber is natural or synthetic. While the other sections of the lab deal mostly with animals, the criminologists tackle the bits and pieces of the crime scene that link a person to the criminal act.
Very Special Agents
Despite all the experience and technology that goes
into solving wildlife cases, solutions would not be
possible without old-fashioned detective work. In federal
and state agencies, thousands of special agents keep
their fingers on the pulse of wildlife crime. Federal
and state wildlife agents, as well as customs agents,
work together to enforce hunting and fishing regulations
and to track illegal wildlife trade. Unlike the scientific
work at the lab, the job of a special agent can be extremely
dangerous. Special agents frequently come in contact
with people who are already armed for hunting, and they
often meet in isolated settings. For suspects involved
in illegal trade, a lot of money is at stake. Animal
parts used in traditional Chinese medicine, for example,
may command upward of $3,000 a pound, in the case of
rhino horn, or $10,000 for the parts of one tiger; these
are strong motivators for wrongdoing.
Undercover operations begin in a variety of ways. Sometimes agents receive a bit of intelligence, as in the caviar case when the price didn’t seem consistent with the product being advertised. Agents also get tips from informants and competitors who want to expose unlawful practices. It is also not unusual for wildlife criminals to brag about their accomplishments, as the suspect in the hyena case did. According to Sal Amato, Special Agent in Charge in the U.S. Fish & Wildlife Service’s branch of Special Operations, agents will also come up with “projects.” By prioritizing a species, a country, or a specific trade, agents can focus their attention on a problem and gather the information they need. Frequently, agents will start long-term covert operations by setting up a false business to solicit illegal business. “At times we work with cooperators,” says Amato, “and a lot of times we just act as individuals.” It is not unusual for a project to last for years.
To gather evidence in the caviar case, there were two covert investigations. In Maryland, a U.S. Fish & Wildlife Service agent from the Baltimore office posed as a buyer for Sutton Place Gourmet in “Operation Malossol.” The agent purchased caviar from the suspicious company, then sent it to the lab to be analyzed. Simultaneously, an undercover Alabama state conservation officer working with the U.S. Fish & Wildlife Service in “Operation Wedgehead” posed as a commercial fisherman and sold illegally harvested roe to the suspect. Between the two operations, agents were able to collect enough evidence for the conviction. Yazback, the owner of the company, was sentenced to two years in prison, and personally fined $100,000. His company was fined an additional $110,000.
Future Forensics
The future of wildlife forensics mimics its past. Scientists
will continue to expand the databases that help them
identify species, match samples from individual animals,
and tie suspects to their victims and crime scenes.
And new technologies will make their work easier and
their results more definitive.
One exciting technology new to wildlife forensics is what is known as retro-engineering. When a machine, such as an airplane, needs a new part, a specialized computer can scan the old part and develop a precise image of it. The scanned information can then be sent to another machine to create an exact copy. Forensic scientists are excited about a few potential applications of this technology. Scans of skulls in a museum can be sent to the lab to help them identify a specific skull or to add to their “collection” of skulls in the lab. Or a puzzling skull at the lab can be scanned and sent electronically to a museum anywhere in the world to help in identification. This technology might be particularly helpful when it comes to sorting dog and wolf skulls, which are still posing problems for the scientists. By scanning multiple skulls, they may be able to find specific characteristics that help them separate the skulls.
Despite all the glitz of the MALDI and retro-engineering technology, the best technological advance of the past ten years is surprising. When asked, Espinoza quickly named “fast personal computers” as the most useful gadget. A decade ago, the scientists were using computers with a tenth of the power they have today. Now, scientists at the lab have the same computer capacity on their desks as they used to have in an entire room. That not only speeds up their work, but each scientist now has a huge database at his fingertips.
Thanks to dedicated scientists and technology, the field of wildlife forensics has grown beyond anyone’s expectations. Many more wildlife criminals are caught and prosecuted than in the past. But, despite the excellent detective work of special agents, there are criminals who deny wrongdoing—right up until their trial date. Even some hardened wildlife criminals seem to have respect for a good scientist, though. According to one forensic specialist, it’s not unusual for a suspect to finally confess when a lab scientist arrives in town with an armful of reports.
—Terry Dunn is a freelance writer living near Sandia Mountain in Albuquerque, New Mexico.
ZooGoer 32(6) 2003. Copyright
2003 Friends of the National Zoo.
All rights reserved.
