The Blood Wasn't Human

By Amy Agronis

Computer-generated image from an automated DNA sequencer, used by the lab to identify individual animals or verify parentage.

UC Davis brings high-tech crime investigation to the animal world.

Police found the barkeep beaten and stabbed to death in the alley outside his London pub. But some blood samples from the scene did not belong to the victim. And further testing revealed the samples were not human at all.

With that discovery, Scotland Yard investigators might well have reached a dead end. Instead, a lengthy search led them across an ocean and a continent to the UC Davis Veterinary Genetics Laboratory.

Housed in a half-dozen trailers on the south end of campus, the lab has long led the world in DNA parentage testing for horse registries like the American Quarter Horse Association’s. But these days it’s not verifying sires and dams that’s prompting the lab to expand and intriguing its technicians like a good Patricia Cornwell page-turner; it’s analyzing crime-scene data from around the globe for law-enforcement agencies, including London’s New Scotland Yard.

The lab started conducting pet and livestock DNA-based forensics work for outside agencies and individuals about six years ago, said Marcia Eggleston, executive director of the lab. Since then the number of forensics cases has grown from some half-dozen a year to 30 in 2001.

“Since the late ’80s or early ’90s the capability has been there, but it was the mid-’90s before we were approached,” Eggleston said. “Now it’s snowballing.”

Criminal case work has included a murder in Indiana, dog and llama abuse cases in Florida, a cattle rustling in Arizona, an assault case in Iowa and big horn sheep poaching in Montana.

Of all the cases, the matter of the slain barkeep was particularly memorable. “We’d dealt with murder cases, but to work with Scotland Yard—it was intimidating,” said Eggleston.

She received the first call from Detective Will O’Reilly in early December 2000. He related how Scotland Yard had looked unsuccessfully throughout Europe and then the United States to find a lab willing to DNA-type the animal blood investigators had discovered. “Basically he was down on his hands and knees begging over the phone,” Eggleston said.

But she was hesitant to agree.

If the lab was going to begin working internationally, Eggleston wanted that first experience to be one that clearly demonstrated not only the capabilities of her lab but also the viability of animal DNA typing as reliable court evidence. Eggleston had yet to testify in a DNA forensics case, and she didn’t relish making her first trip to a witness stand in a foreign country, before a judge and a potentially contentious barrister when the stakes were so high.

From that and subsequent conversations with O’Reilly, Eggleston learned just how exacting Scotland Yard had been in following protocol with the DNA-bearing samples, collecting blood and saliva specimens carefully and promptly and maintaining a strict chain of custody. “It all boils down to the samples; and the investigators were really professionals,” she said.

By his third phone call, O’Reilly had won Eggleston’s confidence. “He was very persuasive,” she said, remembering the Brit’s engaging blend of expertise and wit. “He said, ‘Our court system isn’t like yours. It’s not like Judge Judy; we’re nice to our witnesses here.’”

O’Reilly arrived in late January, hand-carrying the samples. During the next week the UC Davis lab was able to confirm that the non-human sample found in the alley was dog blood. And ultimately, campus technicians were able to prove it came from a dog owned by the prime suspect in the case. “It went like clockwork,” Eggleston said. “This was your perfect forensics case.”

Often, as in the Scotland Yard case, police have a good idea who committed a crime, but they haven’t been able to establish a clear connection between that person and the crime scene, said lab supervisor Glen Byrns. The lab’s work supplies that connection.

“In this case, it would leave the suspect to explain why his dog was cut and bleeding and why his dog’s blood was found next to the body,” Byrns said.

The lab’s work provided a similar tie in a case of sexual assault. During the attack, the victim noticed her dog urinating on a hubcap of the attacker’s pickup. Police later swabbed the tire. And although the suspect denied ever being near the victim’s house, the dog’s DNA perfectly matched the DNA traces left on the man’s pickup tire.

Seeking to assist in the case of Cody Fox, an 11-year-old severely mauled by dogs, the lab offered its services free to the Tehama County Sheriff’s Department. Technicians helped police identify the pit bulls that in September of 1998 attacked the boy, so the dogs’ owner could be held accountable. “If there was any chance of him saying ‘it wasn’t my dog,’ we were going to eliminate it,” Byrns said.

In another case, cat fur found on a suspect’s clothing linked him to a crime inside the home where the cat lived.

Circumstantial evidence? Perhaps. But convincing nonetheless.

“We’re never the smoking gun,” Byrns said. “We’re just one more piece of tape that holds the case together. It shows someone was somewhere they absolutely swear they weren’t.”

Staff researcher Alison Schaffer agreed. “It just adds to the whole picture. Investigators get a preponderance of evidence and plead the case out,” she said.

The lab’s expertise has been persuasive in a variety of situations.

In a recent case, lab technicians were asked by the Oregon Racing Commission to type mucous found around the mouthpiece of an asthma inhaler. Officials suspected the inhaler, which was discovered in the bottom of a tack box, was administered to a race horse to enhance its performance. The inhaler contained epinephrin, which stimulates muscle tissue and induces a surge of adrenaline; it is a prohibited substance in racing, no matter how novel the delivery method.

Technicians confirmed the presence of horse DNA on the mouthpiece. They could have gone further and identified the particular horse, but the commission needed only confirmation of how the inhaler was used so they could put the pari-mutuel racing industry on notice: Officials would now be on the lookout for this method of delivery.

In some cases, the animals have been the victims. Owners have been arrested after dragging animals behind their cars when blood samples taken off a road match the injured or dead animals’ DNA profiles.

And then there are times, like in the Cody Fox case, when animals are the criminals.

In a case the lab worked on a few years back, one of three Great Danes belonging to a Simi Valley woman attacked a 9-year-old boy. Since authorities couldn’t be certain which of the dogs bit the boy, they were considering destroying all three. The pet owner contacted the UC Davis Veterinary Genetics Lab. Torn clothing the boy was wearing—which contained residual saliva and, thus, DNA-bearing epithelial cells—was forwarded to the lab. The DNA profile matched perfectly with blood samples from one of the suspected dogs, and the other two Great Danes were spared.

Forensics testing also identified a dog that in the summer of 2000 killed one miniature horse and maimed another. In that case, traces of blood with DNA identical to that of the dead horse were found along the rim of the dog’s water bowl.

Parentage testing is what put the lab in its unique position to help out on forensic cases. The lab has collected volumes of DNA research and parentage data since it was established in the 1950s and now has an extensive database of DNA samples.

Almost 98 percent of the work the lab does is parentage typing for horse registries worldwide, Byrns said. So, on any given day, it can receive up to 2,000 samples of horse hair to analyze. “We have people who just work with horse hair all day,” Byrns said. The growth in volume has been tremendous, said staff researcher Beth Wictum, noting, “I remember getting excited when we had 100 samples in a day.”

Last year, some 140,000 horses were typed. And Eggleston estimates the lab has some 650,000 individual horse DNA samples on hand. The lab’s DNA sample numbers for cattle and dogs are smaller, at 21,000 for cattle and 10,000 for dogs, “But it’s still very significant statistically,” Eggleston said.

And while the lab usually obtains those samples from hair, it has become expert at extracting DNA from peculiar sources. One of the first such challenges occurred in 1994 when the lab was confronted with a horse parentage case involving a dead sire. The horse was dug up and a sample was ultimately obtained from inside a tooth.

Hundreds of postmortem cases followed. “Those gave us a lot of experience working with unusual samples,” Byrns said.

In addition to animal hair, animal DNA has now been drawn reliably from sources including skulls, saliva, a single spot of dried blood on a piece of wood, dander off a comb, dead skin, urine, feces and animal hides from museums.

Its extensive database is what sets the UC Davis lab apart.

In the Scotland Yard case, overseas labs probably could have extracted the DNA without a problem, Eggleston said, but then what would they have to compare it to? “You have to back it up with statistics. You have to have background on thousands of animals with these markers to generate statistics to back up what you’ve done.”

Neither Byrns nor Eggleston knows of any other labs, university-affiliated or otherwise, that can match UC Davis’ animal forensics profiling capabilities. A U.S. Fish and Game lab in Ashland, Ore., focuses on wildlife only. Shelterwood Labs in Carthage, Texas, can handle unusual animal samples, Eggleston said, but they don’t have UC Davis’ database—DNA profile results from thousands of like animals that prove an individual’s sample is indeed unique.

UC Davis’ lab now maintains rapidly growing databases not only for horses, cattle, dogs and cats, but also for llamas, alpacas, sheep, elk and even beefaloes (a cross between cattle and bison). And future work will include DNA typing of mice for the Jackson Laboratory research facility planned for the campus.

“We used to type 1,000 samples per year. Now we’ll do that before it’s time for our coffee break,” Byrns said.

After processing, a DNA sample taken from blood or epithelial cells presents itself graphically as a series of taller peaks of varying heights separated by flatter areas and shorter peaks. The height of the taller peaks, or markers, and the varying spaces between them are unique to every individual. Up to 24 different markers per typing are compared to known samples during the course of a forensics case, providing a fingerprint that’s unique among millions to billions of individuals.

Charges for testing start at about $300 per typing, and a criminal case usually requires several typings derived from multiple sources—analysis of a blood stain, perhaps, as well as a hair follicle and a swab of saliva. The fee is designed more as a means of discouraging frivolous civil cases—for instance, the homeowner who wants to know which neighborhood dog chewed up his tomato plants—than as a means of generating profit, Wictum said.

The lab also regularly receives inquiries from around the country from restaurant-goers who suspect just maybe they were served horse or dog meat instead of beef. The cost generally discourages individuals from pursuing the matter themselves, Wictum said.

Cases take from a week to a month to resolve. “Getting a good DNA extract is the time-consuming part,” Eggleston said. Some samples have taken dozens of tries, but usually three out of four yield results. Then the effort focuses on checking and rechecking results.

Given the time put into most cases, the forensics work is not always profitable, Byrns said, but it is an important contribution that a public research university can make to benefit law enforcement.

Eggleston agreed. “Some cases pay for themselves, others don’t.” And income from parentage work might have to occasionally subsidize forensics research. But even if the forensics ledger doesn’t always balance, she said, “I think it’s a necessary service.”

O’Reilly interviewed Eggleston before he left and presented the lab with a plaque out of gratitude for its efforts. Fortunately, Eggleston didn’t have to travel to England to testify.

The UC Davis Veterinary Genetics Laboratory has worked on cases ranging in severity from trespassing to triple murders. And while Eggleston has given a number of official statements to police agencies, she has yet to appear before a judge or jury. “Most cases settle out of court,” she said, noting that itself is a powerful statement about the value of DNA profiling as evidence. “And we must be doing good work, because we’re getting good word of mouth.”

As evidence of that, on the recommendation of O’Reilly, another English investigator recently contacted Eggleston. A strand of dog hair—again thought to belong to the suspect’s dog—was found stuck to duct tape used to bind a murder victim. The Kent County investigator brought not only crime scene samples but also news that the defendant in O’Reilly’s case had been convicted and that the UC Davis lab’s evidence had played a key role in that conviction.

“He said word [about the lab] is getting out overseas,” Eggleston said.

Eggleston figures ending up in court some day is inevitable, as was the retooling of the lab to accommodate the demand for more forensics testing. “We could handle the expansion for a while, but then we had to make some decisions,” she said.

One of those decisions was to seek accreditation. Human crime labs must be accredited, but no recognized body sanctions animal forensics labs. A few law enforcement agencies have asked if the UC Davis facility is accredited when inquiring about a potential case, Wictum said, but the negative answer has never seemed to diminish an agency’s interest in using the lab. Still, not being accredited at this point bothers both her and Eggleston. “I think we’re going to get to court some day, and someone will use it against us,” Eggleston said. “We figure, if we’re going to keep scaling up, we’d better do it right.”

The lab plans to seek accreditation from the American Society of Crime Laboratory Directors. Any crime lab may participate in the program to demonstrate that its personnel, procedures, equipment, security, and health and safety procedures meet established standards.

Facility improvements are also being planned. Until recently, forensics work has shared the lab’s some 8,000 square feet of space with genetic disease screening and parentage testing. To boost efficiency, security and work capacity, this spring the forensics testing lab will move into its own restricted-access trailer, where all sample preparation and testing will be performed. “The physical separation will allow the lab to meet minimum facility standards required for accreditation,” Eggleston said.

Meanwhile, UC Davis researchers look forward to new opportunities to work with law enforcement officials from far away places and to put the lab’s volumes of DNA research and parentage data to such meaningful use.

“Parentage testing is important,” said Eggleston, “but when you can help put a murderer or rapist behind bars—or in Cody Fox’s case, prove that these are the dogs that maimed him—that’s really satisfying.”

Amy Agronis is the editor of Dateline UC Davis, a newspaper for faculty and staff. Photos by Debbie Aldridge/UC Davis Mediaworks.