Very often when experts are called into a court case, they already have an agenda. They are asked to testify for one side of the case. They are often paid. In many cases, experts are called upon to state common sense conclusions they have arrived at. But sometimes they are asked to contradict the common sense of the ordinary, prudent person.
Acquiring credentials should not cause a person to lose their judgment. If the expert was honest before getting the credentials, he will be honest afterwards. Some experts get the credentials so they are qualified to pedal half-truths to the court.
In the shower one morning, forensic pathologist Linda Norton was considering the unusual head injuries suffered by Janice Johnson, a Nova Scotia homemaker found near death in a pool of blood. Norton knew another pathologist had concluded Johnson was murdered as a result of a bludgeoning - an opinion that put Johnson's husband, Clayton, 52, behind bars for life.
As the water streamed down, Norton wondered about the absence of bruises or scratches Johnson could be expected to have from defending herself. As she later recalled to Clayton Johnson's lawyer, James Lockyer, she also wondered about the startling lack of marks almost everywhere else on the woman's body, found at the foot of the couple's basement stairs. Norton's deduction flew in the face of the medical evidence accepted by a jury. She concluded that Johnson died after accidentally falling backward down the stairs while rushing to turn a corner to step into the kitchen. "A slight misstep at the point where she rounded the corner can easily be envisioned to cause a backward fall," Norton said.
The federal government reopened the case after studying Norton's conclusion, as well as that of another pathologist. Legal experts believe Justice Minister Anne McLellan will have little choice but to order either a new trial or appeal hearing for Clayton Johnson, who has been in prison for nearly six years.
The case is the latest example of pathologists drawing shockingly different conclusions after studying the same evidence. Increasingly, defence lawyers have turned to independent pathologists to counter any impressions that evidence from prosecution experts is infallible.
Among the cases: Brenda Dalton of Gander, Nfld., died in 1988 from what the province's then-chief forensic pathologist, Dr. Charles Hutton, said was strangulation. Her husband, Ronald Dalton, was later convicted of murder and sentenced to life in prison. But earlier this year, the Newfoundland Court of Appeal overturned his conviction and ordered a new trial after two Prairie pathologists, Dr. Peter Markesteyn and Dr. Harry Emson, examined the evidence. They concluded her throat injuries were the result of resuscitation attempts and that Brenda Dalton had choked on cereal.
Robert Gentles, who was serving a 31-month sentence at Kingston Penitentiary, died after five guards entered his cell and restrained him on his bed during a lock-down on Oct. 24, 1993. Gentles, 23, was asphyxiated, but the consensus ended there. Dr. David King and Dr. Frederick Jaffee said the evidence suggested it was forcible smothering. Dr. David Dexter felt suffocation was possible. But Ontario's chief forensic pathologist, Dr. David Chiasson, concluded Gentles died as a result of "positional asphyxia," an inexplicable constriction of the airways. Chiasson's opinion was later used by the crown as a basis for withdrawing manslaughter charges against two guards.
In July, the Court of Appeal in England found Patrick Nicholls was wrongly convicted and spent 23 unnecessary years in jail for the murder of Gladys Heath, whose death wasn't a murder at all. Heath fell down the stairs of her Sussex home on April 2, 1975, and police originally believed she had a heart attack. However, Nicholls, a friend who found her, panicked and became a suspect after he was seen leaving the house by a neighbour. (He fled because coincidentally another woman collapsed dead at his garden gate a month earlier and he felt police would find this too strange.) Nicholls, who was found guilty of beating and suffocating Heath, was freed after a forensic pathologist in Northern Ireland concluded on the basis of autopsy findings that she suffered an acute coronary and fell backward down the stairs.
There are tremendous expectations that the conclusions drawn by forensic pathologists will be the right ones, given that they could result in someone going to jail. But Julian Falconer, a Toronto lawyer who represents the family of Gentles, believes these experts sometimes arrive at the wrong answers because they're asked to provide more than a neat, clinical opinion on the cause of death, based on an examination of the body during an autopsy. Often, they're asked to consider other circumstantial evidence, he says. "They're trained as doctors, they're not trained as investigators," Falconer said in an interview. "Very often, they're not any more qualified than the average detective."
Lockyer says some nonetheless develop a police mindset. When pathologists are wrong, however, the consequences can be enormous, because jurors tend to give anything these experts say great weight, Falconer contends.
“Forensic pathology is not an absolute science”
-- Dr. Martin Queen
"I think pathologists have a particularly dangerous effect on jurors which extends to society's reverence of doctors - and fear of death," he said. Dr. Martin Queen, a forensic pathologist at the Office of the Chief Coroner in Toronto, says members of his profession are sometimes asked questions in court that go beyond their levels of expertise. "It's important for a forensic pathologist to admit when they don't know something," he said. But that doesn't mean they're stepping out of bounds when they take other circumstantial evidence into account when deciding on a cause of death, Queen says. "Often there is nothing in an autopsy that can differentiate whether someone tripped or was pushed," he says.
"We can figure out whether someone was intoxicated by drugs or alcohol. But in the case of a body at the bottom of the stairs, with a head injury . . . the police investigation of the scene is very important." Circumstantial evidence also becomes important when bodily injuries and the clues they provide are extremely subtle, which can happen in asphyxiation deaths, Queen said. "Forensic pathology is not an absolute science by any stretch of the imagination."