Foon Rhee

Foon Rhee: UC Davis lab takes CSI to the next level by helping police catch killers through pet DNA

Published: Sunday, Sep. 1, 2013 - 12:00 am
Last Modified: Monday, Sep. 2, 2013 - 2:38 pm

It’s a little mind-blowing, but killers are getting caught because they stepped in dog poop at the scene of their crime, or left behind hair from their pet pooch.

Who knew man’s best friend could be a criminal’s worst enemy?

A leader in this expanding frontier in crime-fighting is right in our backyard. The forensic unit at UC Davis’ veterinary genetics lab is the only one accredited by the American Society of Crime Laboratory Directors, and is called upon by police across the country and sometimes the ocean.

Created in 1999 to handle an increasing number of requests to analyze animal DNA, the three-woman unit now works about 100 criminal cases a year.

Sometimes, an animal is the perpetrator, attacking a person or other animal. In other cases, an animal is the victim. To go after dog fighting, the unit played a key role in creating a canine DNA database – now nearly 1,000 profiles – to trace bloodlines and uncover links among ringleaders.

But the forensic unit gets the most notoriety when an animal is the “witness” – when it links a dog or cat’s DNA to the crime scene or the suspect.

Most recently, the unit had a hand in Britain’s first criminal trial in which cat DNA was used as evidence. The lab identified cat hairs found on a curtain wrapped around a dismembered torso found in a garbage bag on a beach last summer. A cat DNA database, which the lab helped set up, tied the hairs to Tinker, a cat belonging to a friend of the victim. David Hilder was convicted of manslaughter for stabbing David Guy during an argument and was sentenced July 30 to life in prison.

While these cases are becoming more common, forensic unit Director Beth Wictum says that animal DNA analysis could help solve many, many more. But budgets for testing are limited – and so are imaginations. Investigators do not routinely collect animal evidence from crime scenes.

“It’s really too bad,” she told me.

So Wictum tries to spread the word to prosecutors and police. In June, she gave a speech and had a booth at the International Homicide Investigators Association annual symposium. “You see the light bulb go on over their heads,” she says.

Obviously, she’s promoting her lab and trying to drum up more business (“When you need to analyze ALL of the evidence,” its brochure says). Still, I get the sneaking suspicion she may be right.

The U.S. Justice Department says that as forensic DNA analysis continues to progress rapidly, one promising area will be using animal DNA, or even plant DNA, to provide leads.

Denver District Attorney Mitch Morrissey, who is a proponent of DNA technology, says it is critical for investigators to collect all potential sources of DNA at crime scenes, along with DNA samples from pets found there or at suspects’ homes. Until that happens more often, animal DNA’s potential as an investigative tool won’t be fully tapped.

“People need to realize it can help solve cases,” he told me.

Using animal DNA evidence involves the same basic principles and equipment as human DNA analysis, which, while not foolproof, is widely used by law enforcement and commonly accepted in courts.

A suspect could be tied to a crime scene by coming into contact with DNA – through saliva, blood, feces or urine – from a pet that lives there. Or a suspect could leave behind hair or other trace evidence from their own pet.

DNA from a hair sample is typically less individualized, so the chances of a match are higher. That often means other evidence is needed to prove a case.

Still, it’s not too far-fetched to imagine a rapist or murderer who is meticulous about not leaving his fingerprints or DNA anywhere, but is tripped up because he misses a stray pet hair on his shirt.

As awareness grows and technology improves, the UC Davis forensic unit is racking up the convictions.

In 2001, it helped in Britain’s first criminal trial using dog DNA. During a fight outside a London nightclub, the doorman was fatally stabbed. Colonel, a bull terrier belonging to the defendant’s friend, was also cut. The dog’s blood led police to his owner’s home – the big break in the case.

In 2002, a man was convicted in the execution-style shootings of three construction workers in Indiana. A key piece of evidence: DNA from dog poop at the crime scene matched excrement on the suspect’s sneakers. In 2008, a man was convicted in a Texas home invasion and rape after he was also linked to the family dog’s DNA from poop in the backyard. And in 2010, an arrest was made in a 4-year-old homicide in Florida partly through dog hair found on the victim’s body that matched dogs raised by the suspect’s sister-in-law.

Curiously, criminal evidence sent to the lab is decidedly weighted toward dogs. “I joke that criminals are dog people,” Wictum says.

The lab bills law enforcement agencies the going rate of $500 to analyze each sample. That isn’t enough to cover its costs, however, or to add equipment or staff. So it is starting money-making ventures. It just launched Meat ID, a $150 test for consumers scared by the horse meat scandal in Europe to make sure what’s in their hamburger. It is also marketing Dogpile ID kits ($58 to start, additional cost for DNA profiles and testing) to apartment managers and homeowner association officers, who can send in samples to find out which residents aren’t picking up after their dogs.

It will likely take a big-dollar private donation, however, to grant Wictum’s biggest wish – a brand new building. I have to admit, it is rather startling to see such cutting-edge forensics being done in such cramped, weather-beaten trailers.

“High tech in low tech surroundings,” says Wictum, who went to work at the genetics lab in 1979 right after getting her undergraduate degree at UC Davis.

She has witnessed all the advances in technology and science since. Now, she and her team are taking “CSI” to the next level. Besides the criminal cases, they identify bones from missing pets. They track cattle rustlers. They trace poachers to protect wildlife and endangered species.

A couple times a year, they even get hairs from someone convinced they’ve spotted Bigfoot. Sadly, the test always comes back that, actually, it was only a bear. If the result were ever different, that would really put the lab on the map.

Follow Foon Rhee on Twitter @foonrhee

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