The Forensic Science of Catching Poachers

Horvat’s corpse was lying in a creek, and he’d been shot in the back. His rifle was missing. Investigators found a doe’s gut pile nearby, but its carcass was missing, too. Investigators collected blood and tissue samples from the gut pile, but found scant physical evidence to explain Horvat’s death.

Seven years later, prosecutors used DNA evidence from the doe’s gut pile to tie Lawrence Cseripko of Uniontown to the murder. They arrested Cseripko in October 2004, accusing him of shooting Horvat, leaving him to die, and stealing his deer.

Why did it take seven years to arrest Cseripko? That’s how long it took to obtain credible genetic evidence to link him to the crime. By the end of the 1980s, U.S. courts almost universally accepted DNA evidence for identifying individual humans. But given the price tag of DNA work and the lack of relevant wildlife databases, DNA evidence remained a relatively untested method for identifying individual animals and solving wildlife-related crimes throughout the 1990s and into the early 2000s.

Police zeroed in on Cseripko in 1998 after learning that he confronted Horvat in 1996 and accused him of poaching a deer. A neighbor with a view of the hunting property told investigators about the run-in and said Cseripko had twice claimed he would kill Horvat if given the chance. When police searched Cseripko’s home in 1998, they confiscated venison from his freezer.

Cseripko denied three times during the investigation that he’d been at the crime scene, even though the neighbor saw him nearby and talked to him that day. The neighbor also told police he warned Cseripko to stay away from Horvat, and that he saw Cseripko drive his truck out of the woods about a half-hour after hearing three gunshots in that direction.

In the years that followed, investigators built a regional DNA database by collecting samples from deer killed by area hunters and motor-vehicle crashes. Finally, in 2004, a laboratory in Saratoga Springs, New York, genetically matched the doe’s crime-scene samples to venison from Cseripko’s freezer. When police told Cseripko about their DNA evidence, he admitted being at the crime scene.

The district attorney charged him with Horvat’s murder, and Cseripko’s attorney unsuccessfully challenged the DNA evidence. When his case went to trial, he was convicted and sentenced to life in prison. Cseripko appealed in 2011, arguing DNA evidence was “junk science” and the evidence shouldn't have been allowed at his trial. The federal judge rejected his appeal.

DNA Jigsaw Puzzles

By current standards, the DNA evidence that helped convict Cseripko was nothing extraordinary. “Genetically matching a buck’s head or a doe’s venison to a specific gut pile or rotting carcass is relatively simple these days,” said Jim Heffelfinger, wildlife science coordinator for the Arizona Game and Fish Department, and a research scientist at the University of Arizona. “But proving a buck’s DNA doesn’t match the genetics of a particular herd is more difficult. Those comparisons aren’t simple.”

Heffelfinger said genetically matching a deer to a herd requires extensive DNA sampling from entire regions, a process that can take years to compile. With enough DNA samples, however, scientists can piece together a multi-colored genetic landscape diagram that resembles a weather forecaster’s heat map. Even then it takes expertise to match or scratch an animal’s DNA from specific herds.

“It’s like working a jigsaw puzzle, where you hold up that one piece while studying the picture on the box to see where it might go,” Heffelfinger said. “But the more pieces you’ve already put together, the easier it is to figure out.”

Meanwhile, scientists in fish and wildlife crime laboratories at universities and agencies across the U.S. keep improving how to apply DNA and other forensic evidence—including ballistics, blood types, and strontium isotopes—to bust poachers and other criminals ranging from timber thieves to black-market meat sellers.

The most famous and comprehensive of these facilities is the Clark R. Bavin National Fish and Wildlife Forensic Laboratory in Ashland, Oregon. The lab—covering over 40,000 square feet and storing hundreds-of-thousands of samples—describes itself as “much like a ‘typical’ police lab, except the victim is an animal.” Besides knowing how to distinguish sturgeon caviar from paddlefish eggs, the laboratory’s scientists can verify if a dried penis sold as an aphrodisiac came from a bona fide tiger or an imposter.

Bear Claws Crack Elk Case

Whatever their task, wildlife forensic laboratories wield microscopes, computers, and bar-coded samples to identify and compare physical evidence to help investigators “link suspect, victim, and crime scene.” As a result, violators often learn they need more than a shovel and zippered lips to fool these experts.

An oft-shared story from the Wyoming Game and Fish Wildlife Forensics and Fish Health Laboratory in Laramie dates to 2006 when a black bear helped investigators solve an elk-poaching case in Colorado.

Four Louisiana hunters poached a 6-point bull elk in a site closed to hunting and tagged it with a permit from a different unit. After loading the field-dressed bull into their pickup truck, the men returned to their hotel in Trinidad, Colorado. A black bear sniffed out the bull that night, climbed into the truck bed to feed, and returned the next night. The hunters tried chasing it off, but then shot it and called the Parks and Wildlife Department. The responding warden confiscated the bear and asked about the big elk. The hunters sounded nervous and evasive, but the elk was properly tagged, so the warden let them go.

Two weeks later, the warden investigated remnants of an elk’s gut pile that someone reported at a site closed to hunting. An informant also claimed the Louisiana men at the Trinidad hotel had poached the big bull. The warden sent samples from the gut pile to the Laramie laboratory, along with the bear’s frozen hide and head. Meat from the bear’s last meal was still evident in its claws, teeth, and head. Scientists genetically matched blood from the elk meat to samples from the gut pile, and the poachers paid over $16,000 in fines.

DNA evidence also tripped up a Wyoming elk hunter who shot a collared wolf he claimed was chasing his Jack Russel terrier. The incident occurred two days before his wolf tag took effect on Oct. 1, 2017. Rather than report the kill, Lane Bunner cut off the wolf’s GPS tracking collar, tossed it collar into a roadside ditch, and drove home to Casper four hours away. He then skinned the wolf, salted its hide, and reported it two weeks later as a legal kill to the Game and Fish Department. As per protocol, Bunner took the pelt and skull to a warden and biologist for inspection and DNA sampling and reported that he shot it a few miles from the actual kill site. He then took the pelt and skull to a taxidermist, who created a display for Bunner’s home.

In early 2020, forensics specialists cross-checked the DNA of all legally registered wolves with DNA samples on file from wolves that had been caught, collared, and poached. They learned Bunner’s wolf had been a 123-pound gray pup when trapped and collared in January 2017. Bunner was fined $3,000 and lost his hunting privileges for four years.

The Elvis Buck

Forensic science isn’t all about DNA evidence. In November 1996, Wisconsin conservation warden John Welke saw a habitual violator driving around town with a giant white-tailed buck in the bed of his pickup truck. The driver, Clyde Masten III, had amassed 27 hunting and wildlife convictions and lost his Wisconsin hunting privileges. He claimed he arrowed the buck in Michigan’s Upper Peninsula, about 230 miles north of his home in southcentral Wisconsin.

The case soon became known as “The Elvis Buck,” because Masten is a part-time Elvis impersonator who still performs today. Masten and a friend, John Owen, told people they drove to the U.P. in the middle of the night, and that Masten arrowed the 11-point buck at dawn after rattling it in. Owen video-recorded Masten trailing and finding the buck, and tagging it with his nonresident archery license. The men then drove home, toured the buck around town, and took it to a taxidermist.

“Their story just wasn’t believable,” Welke told MeatEater. “When I questioned Masten, he told me, ‘Tape don’t lie.’ That was his alibi: Tape don’t lie. They both were lying, but I couldn’t prove it. Six months later, I heard Owen had found religion, so I knocked on his door to try again. He said he knew I’d be back, welcomed me in, and told me everything. He said Masten poached the big buck nearby at night with a .22 rifle, and then they drove straight to the U.P. When I told Masten what I knew, he wouldn’t confess. He said Owen was lying.”

Welke knew Owen wouldn’t make a credible witness, so he sought help from special agent Ed Spoon with the U.S. Fish and Wildlife Service. Spoon called the geology department at the University of Wisconsin-Madison, where Professor Brian L. Beard was using isotopes from strontium, a rare bedrock metal, to identify the origins of unidentified soldiers killed and buried in Vietnam.

The method is so accurate that Beard identified the origins of three soldiers sharing one grave. His analysis accurately indicated that one soldier had lived in northcentral California; one was born in Michigan’s U.P., but lived much of his life in Detroit; and the other was born in Vermont, but lived much of his life in Massachusetts.

“Strontium isotopes vary by region, and they’re retained in plants, water, and soils,” Beard told MeatEater. “If you live anywhere long enough, your blood, bones, and teeth retain strontium isotopes from the food you eat. By measuring those levels in a person or animal’s bones and teeth, we can determine where they lived.”

After retrieving the 11-pointer’s rack and skull plate from Masten’s taxidermist, the wardens gathered six sets of deer antlers and skull plates from nearby lands, and another six sets from around the buck’s alleged kill site near Bruce Crossing, Michigan. They took their evidence to Beard, who matched “The Elvis Buck” with the bones/antlers from Masten’s home turf in southcentral Wisconsin.

Mountains or Musselshell?

Beard later helped Montana game wardens nail a Wisconsin hunter in 2001 after he and his hunting partner left a mostly spoiled bull elk with a meat processor near Musselshell, north of Billings. The processor called investigators after the suspect told him a suspicious story about killing the bull 350 miles away near Lima in the mountains west of Yellowstone National Park. When wardens eventually questioned the suspect, Michael Schreck, he couldn’t describe the area where he supposedly shot the elk, or name any of its ranges or drainages.

The wardens supplied Beard with elk bones and antlers from around Lima and Musselshell, and his Strontium isotope tests revealed Schreck’s bull was from the Musselshell area. “(Schreck) had a tag for the mountains, but he hunted around the Musselshell River, where it’s tougher to draw a tag,” Beard told MeatEater. “We were able to show he killed that bull in an area where honest people can wait a lifetime for a tag.”

Scientists also help fish-and-wildlife agents crack cases involving waterfowl and other migratory birds. Pepper Trail, a forensic ornithologist at the Bavin federal laboratory in Oregon, created the Feather Atlas, an online searchable database that helps fellow scientists and federal agents quickly identify the species of individual feathers. Pepper’s atlas features over 400 species and 1,800 scanned images of flight feathers from North American birds. The site also attracts over 1.5 million visits annually by birders and artists.

Trail’s expertise goes deeper than feathers, of course. In one celebrated case, Trail received a “doggy bag” container from federal agents in New England who visited a restaurant after hearing its menu included wild woodcock. “Timberdoodle” can be legally hunted across the nation’s Northwoods, but it’s illegal to sell their meat. The agents ordered the dish, requested another woodcock meal to go, and shipped it to the Bavin laboratory for scientific verification. After Trail identified the breastbone as a woodcock’s, the Fish and Wildlife Service raided the restaurant and confiscated dozens of the popular gamebird.

Identifying Stolen Logs

Likewise, trees carry DNA evidence that allows scientists to match stolen wood to individual stumps. That’s how prosecutors convicted Justin Andrew Wilke, 39, after he led a crew of night-time poachers into the Olympic National Forest near Elk Lake in August 2018 to cut and haul out prized bigleaf maple trees.

Bigleaf maple renders a luxurious-grain wood that’s prized for making violins, guitars, and other stringed instruments. Logging is forbidden in the Olympic, a nearly million-acre wilderness, and so Wilke used forged permits to sell the logs to a mill. During Wilke’s trial in July 2021, a research geneticist with the U.S. Forest Service testified that DNA evidence matched the wood to three stumps in the public forest.

The geneticist, Dr. Richard Cronn, told the New York Times that trees—as with all living organisms—have DNA that links them to specific parents. “They receive one set of chromosomes from their mom and their dad,” Cronn said. “That makes it possible to uniquely distinguish every tree out there if we have the appropriate genetic markers.”

The tree poachers were also linked to a fire that burned 3,300 acres and cost about $4.2 million to contain. The jury didn’t convict Wilke of the fire, but in November 2021 he was sent to jail for 20 months after being convicted of conspiracy, theft of public property, trafficking in illegally harvested timber, and other charges. A member of his crew is serving a 30-month prison term for the fire and theft of public property.

Identifying & Tracking

In fact, forensic evidence is so reliable that law-enforcement officers can often coax violators to confess without going to court. Wisconsin wardens used strontium isotope evidence to bust a ring that tried passing off illegally trapped Wisconsin river otters as legal catches from Mississippi, a state with a higher bag limit. Likewise, Michigan researchers in the early 2000s helped agents use DNA evidence to show that bobcat pelts from the lower peninsula were being illegally registered in the Upper Peninsula, where the bag limit was higher.

Forensic evidence also positively identifies and tracks wolves, cougars, and grizzlies as they disperse and travel long distances. Hair, scat, or urine they leave behind proves not only the animal’s species but also its individual identity. That’s how scientists verified a mountain lion killed in 2011 on a Connecticut highway near New York City was the same young male that dispersed from South Dakota and triggered trail cameras in Minnesota and Wisconsin. Biologists assume it then crossed Michigan’s Upper Peninsula, into Ontario, Canada, and through upstate New York before its 1,500-mile trek ended as a world-famous roadkill.

Other notable DNA-verified rare-mammal cases include 11 wolves killed south of the St. Lawrence River since 1993 in Vermont, Maine, Quebec, New York, Massachusetts, and New Brunswick. DNA evidence also proved a large “coyote” shot in March 2013 by a Kentucky hunter was the state’s first documented wolf since the mid-1800s. And nearly one year later in February 2014, DNA evidence documented Iowa’s first wolf in 89 years after a hunter shot a large “coyote” and asked the Iowa Department of Natural Resources to examine it.

What Lies Ahead?

Forensic scientists haven’t ended their efforts to extract more irrefutable evidence from even smaller samples. Researchers in Australia are exploring how to retrieve poachers’ DNA from the hair of animal hides, and Scottish researchers are refining methods for recovering and testing human DNA from spent shell casings ejected from firearms.

Assuming such methods render reliable, affordable evidence, state and federal agencies will be able to bust even more violators. Still, all agencies must make tough decisions regarding when to use forensic science, given their budgets and staffing.

“If you provide good samples that labs can work with, they usually don’t take long to connect the dots,” said Ed McCann, the law-enforcement training supervisor for the Wisconsin Department of Natural Resources. “But forensic science isn’t cheap, and it’s not as easy as it looks on ‘CSI.’ You don’t use it for routine cases. Before you ask scientists to get involved, you have to explain why it’s a good investment for the lab and the state. Forensics work sends a staff through a lot of hoops, so it must warrant their time, effort, and resources.”