The Heroic Cockatoo: The Murder of Kevin Butler
On Christmas Eve 2001 in the Pleasant Grove section of Dallas, Texas, Johnny Serna and Daniel Torres broke into the apartment of Kevin Butler in a hunt for valuables, after a long-running dispute with Butler over money.
Watch: Police encounter a bizarre crime scene when they find a man stabbed to death in his home and his pet bird dead beside him. Investigators soon discover that the bird's brave final acts will lead them straight to the killer.
Unfortunately, despite the bird's heroic efforts, Butler was stabbed to death and the killers escaped. Police found Bird's lifeless, featherless body at the apartment; the cockaoo had been stabbed with a fork.
But while protecting his owner and ultimately sacrificing its own life, Bird helped convict the killers.
Investigators found Daniel Torres' DNA on a light switch at Butler's home. After being pecked in the head by Bird, Torres touched his wound and then touched the switch, leaving behind the valuable evidence.
When there is an animal case involving an atypical species such as a bird, turtle or even camels, forensic scientists have the flexibility—unlike human DNA specialists—to develop special tests or analysis to pinpoint evidence, says Christina Lindquist, director of forensics at University of California, Davis Veterinary Genetics Laboratory, the only accredited DNA animal-forensic lab in the U.S.
"As animal scientists, we never know what's going to come in, but because we can develop analysis in-house, we can provide strong and interesting clues to law enforcement," says Lindquist.
The Cat Convicts: The Murder of Shirley Duguay
When mother of five Shirley Duguay vanished without a trace from her Prince Edward Island home in October 1994, police suspected her common-law husband, Douglas Beamish, whom she had left two years prior.
Friends and neighbors told investigators about the couple's brutal 12-year relationship and Beamish's violent past, which included stints in prison.
But police were stymied, because they had nothing to connect Beamish with the crime.
Three days later, during a massive manhunt of the island, investigators found a bag that contained a jacket and shoes stained with Duguay's blood. Tests revealed Beamish had the same shoe size, and the soles had been worn in such a way that was consistent with his gait, but still nothing conclusive for the crime.
Yet tucked away inside the jacket lining were 20 white cat hairs.
The evidence might have gotten lost in the shuffle except for the work of one policeman, Constable Roger Savoie. He noticed a white cat, Snowball, at Beamish's house during an earlier interview. Convinced there was a connection, against all odds—as animal DNA had yet to be used in a court case in Canada—Savoie found a geneticist in the U.S. who confirmed the hair was Snowball's.
Diane Balkin, senior staff attorney at the Animal Legal Defense Fund, says law enforcement should investigate any pets when a homicide involves a domestic partnership.
"Cats have a huge amount of fur transfer," says Balkin."Pay attention if there is a litter box. Dogs [that] are transported in cars can lick windows or leave nose print or paw prints. Also just be aware if there is violence against a woman, an animal can be involved [as well]."
Dogs Used as Weapons: The Murder of Oluwaseyi 'Seyi' Ogunyemi
Two pit bulls were used to hunt and attack 16-year-old Oluwaseyi "Seyi" Ogunyemi in South London in April 2009 during a rival gang attack. The dogs' owner, Chrisdian Johnson, let the dogs go, and the animals ripped clothes off the fleeing boy and bit him repeatedly.
Seyi tried to climb over a fence, but the dogs repeatedly pulled him down to where the boy was stabbed repeatedly until he died.
A police investigation revealed two gangs were operating in the area where the attack took place. But detectives had little else to go on, until they found a blood trail left by one of the dogs used in the attack, which they followed to Johnson.
Using pioneering DNA techniques, scientists were able to conclusively link the saliva and blood to Johnson's pets: an adult male pit bull-mastiff cross named Tyson and an adult female pit bull-Staffordshire cross called Mia. The samples collected proved the DNA was a billion times more likely to come from those two dogs than any other animal.
Johnson was later convicted of murder. It was the first time the new DNA techniques were used in a murder trial in the U.K.
"When dogs attack we get evidence on clothing, we can pinpoint the saliva on the clothes and then compare to enormous dog and cat databases to find the perpetrators," says Lindquist.
Missing Child Found Using Dog Hairs: The Murder of Danielle Van Dam
In February 2001, 7-year old Danielle Nicole Van Dam disappeared from her bed in San Diego. Her frantic parents didn't know exactly when she disappeared—at night or early the following morning—and police had very little to work on.
Then a suspect slowly shifted into view—David Westerfield, who lived alone across from the Van Dam house. He was a meticulous gardener who left his house the morning Danielle was discovered missing. While other neighbors assisted in searching for the missing girl, Westerfield packed up his RV and left.
Because of Westerfield's suspicious behavior, police obtained a search warrant for his house. Inside, police found dog hair similar to that of the Van Dam family’s dog.
"This is the kind of case we've seen most often, when we find a body wrapped in a comforter, sheet or tape, and there is animal hair stuck in the material," says Lindquist. "The unique thing about animal hair is that dogs and cats groom themselves, so they are putting saliva on the shaft of the hair. We are more likely to find DNA [on animal hair] than on human hair because animal saliva is individual. Then animal DNA can be used as one of the pieces of the evidence puzzle."
