Wrongful convictions, when they occur, usually are based on inaccurate eyewitness testimony. The convicted defendants are exonerated typically through scientific or forensic evidence establishing that the incarcerated individual was not the true culprit. Forensic evidence becomes the great key, freeing those who have been unjustly convicted.
But the science of the day can be an imprisoner as well as a liberator. Witch trials, after all, involved forensic testimony about bite marks as well as expert testimony on the power of spell-casters. The September Trial of the Month considers another case of flawed forensics.
Ayers Rock pushes out of the dry Australian earth. The Aboriginal people call the rock Uluru and consider it sacred. Tourists come to this sandstone monolith to watch its dramatic colors change as the sun moves across it. On August 17th, 1980, Michael and Lindy Chamberlain began exploring Uluru with their three children, Aidan, Reagan and ten-week old Azaria. The older boys hiked with their father. Lindy, meanwhile, carrying Azaria, searched a nearby cave. Reportedly, Azaria was dressed in a jumpsuit and a white jacket.
That night, the Chamberlains and other campers gathered near their campsites. Lindy put her two youngest children to bed and, ten minutes later, rejoined the campers. A baby’s cry sent her racing back to the tent. Campers heard her scream, “My God, My God, the dingo’s got my baby!” (When I mentioned the case at my house, no one remembers the events, but the adults recall Meryl Streep shouting this line in the movie, A Cry in the Dark.)
The other vacationers searched the arid land for the child. Michael did not join the search. His odd explanation, “she’s probably dead now. I’m a minister of the gospel.” (Michael served as a Seventh Day Adventist minister.) The searchers discovered dingo tracks but no other evidence. The police quickly became involved.
A week after the disappearance, a photographer hiking near the base of Uluru found shredded infant clothing near a boulder.
On August 28th, Detective Sergeant Graeme Charlwood assumed responsibility for the investigation. He faced some incongruous facts. The clothes had been found close to where the family had hiked earlier in the day. Witnesses who saw Lindy at camp reported seeing her with a white bundle pressed to her chest and “assumed she was holding a baby”. A doctor who earlier had examined Azaria found her name curious and looked it up. He reported that it meant “Sacrifice in the Wilderness”. (It is, actually, a Hebrew name translating to “God has helped”.) Supporting Lindy, the initial police examination found paw prints leading away from the tent and a bit of blood inside.
Around Australia, investigators imagined and conducted experiments. Dead dingoes from the region were examined for evidence of human proteins. The stains on the recovered clothing were tested. At a wildlife reserve, meat wrapped in baby’s clothing was tossed to dingoes to observe the tear patterns. Allegedly, the early investigators on the case tried carrying a ten-pound bucket of sand in their teeth to see if Azaria’s weight could be managed in the jaws of a dingo. (None of the investigators could carry the pail.)
The accumulated “science” coupled with the odd demeanor of the devout Chamberlain family convinced many that they were guilty. Rumors abounded that they killed their child as part of a bizarre religious sacrifice.
In December 1980, at a coroner’s inquest, the authorities argued that the parents and not dingoes were responsible. The evidence they argued was inconsistent with a dingo attack. The coroner found that Azaria’s parents were not responsible for her death. He did not, however, rule out the possibility that an unknown human had taken the child from the dingo.
The authorities did not relent. In September 1981, they searched the Chamberlain’s home based in part on the findings of a British forensic expert that no dingo had been involved in the disappearance. This search found evidence of blood in the Chamberlain’s car.
At a second inquest this recovered blood loomed large. An expert identified it as fetal blood. The British expert, James Cameron, testified that the tears on Azaria’s clothing were more consistent with scissors than a dingo attack. The coroner charged Lindy Chamberlain with murder and Michael with being an accessory.
The trial began in Darwin on September 13, 1982.
The Crown’s civilian witnesses supported the defense as much as the prosecution. They confirmed that Lindy had only briefly left the crowd at the campground. She returned to the tent only after a baby cried. The witnesses testified to dingoes in the area. One mother testified that earlier she had to scare off a dingo which had grabbed her 12-year-old daughter’s arm and pulled. The Crown called a hitchhiker the Chamberlain’s had picked up. He testified that he had bled in the car. Blood tests, however, showed that he did not test positive for fetal blood. Fetal blood disappears from the human body at approximately six months of age. The Crown presented the fatalistic answers Michael Chamberlain had made on the night of Azaria’s disappearance.
The prosecutors then began the parade of forensic experts. Esteemed witnesses testified that the baby’s clothing had been “cut” in the neck area. Others found jumpsuit fibers in Michael Chamberlain’s camera bag. (The Chamberlains maintained that they occasionally used Michael’s bag as a hamper for Azaria’s spare clothes.)
The government’s blood expert conceded that she had destroyed all her examination slides, thus preventing a re-examination. She maintained, nonetheless, that the blood found in the car belonged to an infant.
The closing Crown witnesses included a London odontologist who had investigated two dozen dog attacks. He found nothing consistent with a dingo attack in this case. The final witness, James Cameron, testified that Azaria was killed by a cutting instrument across her neck. He produced ultraviolet light photographs showing evidence of bloody fingers near the neckline.
The defense marshalled their own army of experts. They challenged each of the Crown’s main contentions. When the government’s expert testified that a dingo could not carry off a child by the head, they surprised him with a photograph of a child-sized doll being carried by a dingo in exactly that manner. They demonstrated that the ultraviolet “fingers” had four phalanges, one more than Lindy Chamberlain and nearly every other human possesses. The different stories presented by the Crown and the defense compelled the jury to choose between attacking dingoes and cruel humans. To the surprise of most observers, they convicted the Chamberlains on October 29th, 1982. The judge sentenced Lindy to life imprisonment while Michael’s sentence was deferred.
Following conviction, the case began to unravel, although it did take time. In 1986, the search for a lost hiker near Uluru discovered a shredded infant’s once-white jacket in a dingo lair. The jacket bolstered Lindy’s explanation. The Crown’s blood testing method, pivotal in the trial, was shown to be highly unreliable. The positive proof of fetal blood recovered from the car could as likely have come from auto paint. Lindy was released from Berrimah prison on February 7, 1986.
Child murder grips everyone. The dingo case presented horrific, inhuman facts crying out for a response. Well-meaning authorities, seeking justice, fell afoul of confirmation bias. They sought facts to support a conclusion they’d made about the Chamberlains—people whose beliefs and reactions placed them outside the mainstream. Although prosecutors could never truly find a motive why these parents would kill their young daughter, they relied upon unconfirmed and, ultimately, unreliable tests to achieve a result. Well-intended passion produced an unjust result.
The case provides a cautionary tale for anyone who looks at or relies upon forensic science. Of course, hindsight is easy. It is harder in the moment for scientists, prosecutors, and police to heed the words of Tony Jones, government pathologist in the Chamberlain trial.
“The scientist shouldn’t become too adventurous, too competitive. The trouble is, we’re all so human. I’ve never seen a case more governed by human frailties.”
For the caution it urges in all our scientific endeavors, this trial which began September 13th, 1982 is my Trial of the Month.