Proved Guilty by a Hair

DAVIS, Calif. —  The two men wrapped Elizabeth Ballard’s body in plastic. They vacuumed and scrubbed the room in which she had been killed. They scoured the car trunk in which they transported her corpse to its shallow grave in the New Mexico desert.

They tried to cleanse the world of anything linking them to Ballard’s death. A single dog hair thwarted them.

It belonged to Hercules, a reddish-brown pit bull mix owned by one of the men. The hair was found on one of Ballard’s socks and helped send the pair to prison for her 1998 murder.

The hair was matched to Hercules in a laboratory in this Northern California college town, where scientists are pioneering the use of animal DNA as evidence in criminal cases. They are fingering suspects around the country with the genetic analysis of pet hair and blood, even feces and urine.

In some cases, Spot and Puff are providing evidence against their owners’ killers. In others, they are convicting the owners themselves.

The blood of a Seattle dog was instrumental in convicting gang members who murdered the couple it lived with. Urine sprayed on a truck tire by an Iowa farm dog helped identify his owner’s assailant. Bits of dog feces on a shoe implicated a suspect in the execution-style slayings of three Indiana carpenters.

Though genetic testing has played an integral role in wildlife forensics for more than a decade--linking game poachers and smugglers to their prey--law enforcement has begun to use animal DNA in criminal prosecutions only in the last few years. Still relatively rare, pet DNA evidence could become a valuable forensics tool, say criminal experts.

Specimens often wind up here, either in the UC Davis Veterinary Genetics Laboratory or the offices of scientist Joy Halverson. For now, these are among the few places in the country where authorities can go for pet DNA testing. The veterinary lab even performed work for Scotland Yard earlier this year, analyzing dog blood samples collected after a pub killing.

The ability to conduct animal DNA testing at a level sophisticated enough for criminal trial use is a product of two developments: the last decade’s astounding advances in human gene-mapping techniques and the creation of genetic databases for various domesticated animal species.

“A lot of the technology is a fallout from the human genome project. We just applied that to animals,” said Beth Wictum of the Davis veterinary genetics lab, which has developed animal DNA profiles for genetic screening and parentage verification of livestock and pets.

The first introduction of pet DNA evidence in a criminal court case is believed to have occurred in Canada in 1996, when prosecutors used cat hairs found on a bloodied jacket to link a Prince Edward Island man to the murder of his estranged wife.

The DNA match was made at the National Cancer Institute in Maryland, which has done extensive research in cat genetics for its work on human disease.

“It just so happened the [genetic markers] we developed for the cat map had forensic potential. We got enlisted in forensics,” said cancer institute staff scientist Marilyn Menotti-Raymond, who, with colleague Stephen O’Brien, performed the cat hair analysis.

Their lab was too small to do ongoing criminal casework. But it did sign a $265,000 contract with the U.S. Department of Justice to develop a feline genetic database for forensic use. Menotti-Raymond is collecting DNA samples from the 37 pure cat breeds and expects eventually to move on to mixed breeds.

Genetic Profile of Species Required

To say with a high degree of probability that a tissue sample comes from a particular animal and not just any dog or cat requires a genetic profile of the species--basically a map of genetic variability within the species.

The UC Davis lab has genetically profiled nearly a dozen domesticated species for pedigree work, so when it makes a DNA fingerprint of an individual animal, the lab can say how rare that particular sequence of genetic markers is.

If the lab matches DNA from samples, it can say, for instance, that there is a 2-in-a-billion chance or less of such a match occurring--roughly the same odds used in human DNA matches.

“Anybody can DNA-type an animal, but unless you know how frequently the markers appear, it’s not going to be informative,” said Wictum, forensics case manager at the UC Davis lab.

The lab’s forensic testing, which has involved homicides, stolen livestock, dog maulings and animal abuse, is a tiny fraction of its workload--one or two cases a month compared with more than 3,000 samples a week processed to verify animal parentage or screen for genetic disease. But the criminal cases stand out.

“You see really bizarre types of people and what they do to each other and to animals. It can be sad,” said Teri Kun, a research associate who devotes about half her time to forensic work. “But when it matches up and they’ve got the right person, it’s nice to be a part of that.”

The work can be painstaking, involving repeated testing of minute quantities of concentrated material.

“I really hate to give up on a case. I’ll keep going back and going back,” said Wictum, who likes to replicate results several times before reporting them.

One of the lab’s more challenging samples came from Indiana, where St. Joseph County prosecutors had a suspect’s shoe and a footprint from the scene of a triple homicide about 80 miles east of Chicago. Three carpenters working at an upscale residence had been found bound and shot in the head, the apparent victims of burglars.

The footprint had been lifted from dog feces on a sidewalk leading from the carpenters’ bodies. A shoe belonging to the alleged triggerman had bits of feces clinging to it. Authorities wanted to see if they matched the sidewalk print.

They did--something that gives prosecutor Scott Duerring metaphorical, as well as professional, satisfaction.

“If I can use this kind of evidence to eliminate a person like this from our society, it fits,” said Duerring, who is preparing for trial in the case.

‘An All-or-Nothing, One-Time Shot’

The shoe specimen was tiny, making the first tests critical.

“In this case it was an all-or-nothing, one-time shot, and we got results, very beautiful results,” Kun said.

In the Iowa case, investigators sent the veterinary lab swabs of dog urine. They had been taken from the tire of a pickup driven by a man suspected in a 1999 attempted sexual assault at an isolated farm in the northeastern part of the state.

The victim, who fought off her assailant as he tried to drag her into the truck, left fingerprints on the vehicle. But when he was picked up based on her description, the woman could not positively identify either the truck or the driver.

Doug Strike, then chief deputy in the Chickasaw County sheriff’s office, was looking over the pickup with an investigator when they noticed a stain on the tire.

“We knew there was a farm dog on the place, and we thought maybe the dog peed on the tire,” remembered Strike, who is now police chief in Iowa Falls. “I went out and talked to the lady, and she said, ‘Yeah, the dog was in the yard.’ ”

Strike swabbed the mouth of the dog, Rover. A detective took swipes from the tire. The genetics lab matched the specimens, and the suspect pleaded guilty to an assault charge.

Joy Halverson’s work has also played a key role in various criminal convictions.

The UC Davis veterinary school graduate has spent 16 years working in animal genetics, first in a research job at the university and then with private companies.

In 1989 she founded Zoogen Inc., which used DNA typing to determine the gender of exotic birds, something that previously required surgery. The company, which later merged with bigger players in the genetics field, branched into parentage testing for livestock and pets.

By the late 1990s, law enforcement was calling Halverson’s Davis office about criminal cases, taking her into a world far removed from small-town academia.

“I live a pretty sheltered academic community life,” said Halverson, who is married to a UC Davis genetics professor and has two college-age daughters, two dogs and two cats. “I’m just intrigued by this.”

This fall she left PE AgGen, where she was a senior scientist, to once again launch her own operation. Her bread and butter will be bird gender testing. But under the name QuestGen Forensics, she is also doing animal DNA typing in criminal and insurance liability cases.

One of the cases that drew her into forensics work was the Ballard murder.

Ballard had been Christopher Faviel’s girlfriend during a break in his relationship with Charles Martinez, a transvestite who went by the name of Eva. When Faviel and Martinez got back together, Ballard continued to see Faviel and publicly harassed Martinez for his cross-dressing.

One night when she showed up drunk at the men’s house, Martinez hit her over the head with a thermal coffee carafe and then strangled her with Faviel’s help, according to prosecutor Canon Stevens.

The men told friends what happened. Word got to the police. When Ballard’s body was discovered a month later, her hair had been scattered over the desert by coyotes, making it difficult to collect trace evidence. But the state criminal lab did find a few animal hairs on the socks Ballard was wearing.

One hair had a root. Lab analyst Philip Aviles thought it might be tested for DNA. He just didn’t know where. He searched the Internet and came across a Seattle homicide case involving dog DNA.

That led to Halverson, who had analyzed the Seattle canine evidence. Via Federal Express, she was sent a DNA extraction from the hair root and a blood sample from Hercules, Martinez’s dog. The hair and blood matched, placing Ballard in Martinez and Faviel’s home, despite their insistence to police that she had never been there.

Halverson had made her first courtroom appearance earlier that year, when she testified in the Seattle case. Two men were on trial in a double homicide.

“Some,” said prosecutor Timothy Bradshaw, “would call it a triple homicide.”

A young couple had been shot to death in their South Park house by intruders searching for drugs and money. The couple’s dog Chief, a Labrador-pit bull mix popular with neighborhood children, was also shot. He died 30 hours later in surgery. When police arrested two suspects in the December 1996 slayings, they found blood on the arm of a leather jacket belonging to one of them.

Evidence Seen as Important to Case

The blood was sent to an East Coast lab, but test results indicated that it was not human. Bradshaw, senior prosecuting attorney for King County, said he and detectives remembered the two bloody wounds Chief had sustained and decided to try animal DNA testing. Through a national kennel club they found Halverson, who matched the jacket blood to a sample taken from Chief during surgery.

Though there was other trial testimony linking the men to the killings, Bradshaw said Chief’s DNA evidence played an important role in their murder convictions.

“We argued that one of the ironies in the case was that the victim who couldn’t speak wound up providing the most eloquent evidence,” Bradshaw said. “He ended up serving his roommates quite well.”