But then Stroud makes a contrary finding. Using a long wooden dowel to probe the entrance wound, Stroud traces the bullet's path through the belly and up through the chest. "It hit the postcava," he says, referring to the large blood vessel that leads from liver to heart. Consequently, the wolf would not have gotten far before dying of massive blood loss. Stroud will tell the special agent to figure that the wolf was shot within a 100-yard radius of the spot where he found the carcass.
Stroud finishes skinning the wolf with a kitchen fillet knife, then lays
the intact pelt, fur side down, on a tarp spread across the concrete floor of the necropsy suite. He again threads the long wooden dowel through the entrance wound on the rear, left flank and pushes it across to the ragged exit wound behind the right shoulder.
Stroud's assistant, Shelley O'Connell, steps up to take a photograph that Stroud says will help him show a jury that the wolf was clearly running away when shot. This may prove
crucial in refuting any claim that the
animal was shot in self-defense.
The size of the exit wound, in turn, speaks of someone firing the bullet from a high-powered weapon such as a rifle, but not using a typical hunting bullet, which would have left a larger, more ragged hole. Military ammo, Stroud speculates. But only a ballistics report on an actual bullet fragment or casing can confirm his suspicions.
For now, the dismembered wolf goes back in the deep freeze--folded, compressed, and bagged in bundles sealed with evidence tape and tagged to show chain of custody. Any criminal case will likely go nowhere unless some combination of luck and skill leads the field investigator to the crucial evidence.
Eventually, the wolf's pelt may end up in a classroom or nature museum; its skull in a research collection, after being rendered down to clean bone by the colony of flesh-eating beetles that the lab's forensic morphologist keeps in a large box.
Stroud averages 500 to 600 such necropsies a year. Last year alone, they included a record 24 wolves and around 150 eagles, as well as scores of other animals protected under the provisions of the U.S. Endangered Species Act or by other laws. Still other cases involve "illegal takes," as when hunters use firearms during archery-hunting deer season (often faking a legal kill by sticking an arrow in the bullet hole), use nets to harvest fish in streams open only to hook-and-line sports fishing, or shoot animals from aircraft (a violation that Stroud has documented by the angle of gunshot wounds).
In each case Stroud must go beyond merely determining cause of death--the traditional role of the veterinary pathologist. "To your typical veterinarian, a gunshot wound is a gunshot wound. End of story," he says. By contrast, a forensic autopsy is built around re-creating the death in a way that's useful to a criminal investigation. In poisonings, for example, Stroud must not only retrieve tissue samples for toxicological analysis, but also determine whether the resulting wildlife deaths were deliberate.
In the recent mass poisoning of a bald eagle colony in Wisconsin, Stroud found that the birds had gorged on muskrats--and pellets of highly toxic pesticide carbofuran. Could the muskrats have eaten the pellets in some farmer's field before their dying convulsions made them easy prey? A superficial necropsy would have suggested so. But Stroud noted a suspicious absence of fur in the eagles' gullets, then went on to document knife marks on several undigested chunks of muskrat. His conclusion: The muskrats had been skinned.
This detail ultimately led investigators to a muskrat trapper who reported selling meat to the owner of the land where the dead eagles were found. Skinning would have involved gutting the muskrats, so any carbofuran pellets found with the meat had to have been added intentionally before it was set out for the eagles' dining pleasure.
"Apparently the eagles' roost tree was on property that the land owner wanted to develop," says Stroud. "But under the Endangered Species Act,
the habitat of a threatened species is also protected."
A somewhat similar case involved a Minnesota man suspected of a string of wolf poisonings in the mid-1990s. From the necropsy of the latest victim, Stroud sent samples of brain, liver and kidney for toxicological analysis, and chunks of deer meat from the wolf's stomach for DNA analysis. The toxicology report confirmed Stroud's suspicion that the wolf had died of massive cyanide poisoning (evident on necropsy by bright red tissues). DNA analysis matched the chunks of deer inside the wolf to venison found in the suspect's freezer.
Both the above cases resulted in convictions, says Stroud, who has taken the witness stand around 25 times in the past 15 years, a modest number given the hundreds of necropsies he has performed. Nonetheless, the Fish & Wildlife Service is impressed enough to have pledged $12 million for a new forensic pathology suite at the Ashland facility, slated to be built within the next three years.
"It'll look just like a state-of-the-art medical examiner's office," says Goddard. And that's exactly what it will be.
Additional reporting by Dawn Stover