Junk Science The Handmaiden Of Junk Justice
More than once I have heard a prosecutor in trial urge a judge to admit contested evidence: "The state cannot prove its case without this evidence, your honor," the argument goes. To which I typically respond: "So what?" The rules of evidence require reliable evidence. The trial deck is not supposed to be stacked in favor of conviction.
But the deck is so stacked. And few judges seem prepared to do much about it.
This is rarely so clear as in the case of expert testimony in cases with no victims, or victims who cannot testify. In such cases, the evidence of a crime must be circumstantial: There are no eyewitnesses who can describe the event. Circumstantial evidence, evidence of things seen permitting an inference about things unseen, is, despite television warnings to the contrary, as probative as eyewitness evidence.
But this business of drawing inferences is dangerous. A jury can draw the wrong conclusion and send an innocent man or woman to jail.
Consider the case of so-called "shaken baby syndrome." In such sad and tragic cases, an infant dies. A medical examiner finds burst blood vessels in the infant's eyes, bleeding around the brain, and a swollen brain. This fateful trio is a sure sign that the child came to violence at the hand of a person who had cared for it, the prosecution contends.
Each year, more than a thousand infants die and present with such symptoms. Their mothers, fathers and babysitters are then investigated, and often prosecuted. Hundreds of custodial care givers are now in prison because of the presence of these symptoms.
The sad fact is that many of these folks are innocent. These symptoms can occur in the absence of criminal conduct.
Last year, the American Academy of Pediatrics recommended that the diagnosis of "shaken baby syndrome" no longer be used. In the language of the law, the diagnosis is a result of junk science: flawed methodological premises yielding unreliable conclusions. Uncannily, the pediatricians' findings reflect a general tendency on the scientific community to reject much of the science that is routinely admitted in a courtroom to prove a defendant guilty. The National Academy of Sciences published a comprehensive report recently noting that much of what passes for reliable evidence in a courtroom would not pass muster in a laboratory. Among the areas of evidence suspect by the Academy: bite-mark analysis, firearms evidence and even fingerprint evidence. Only DNA evidence passed rigid methodological muster.
So why are the courts so quick to admit questionable scientific evidence?
I suspect the answer is that the state could not prove many of its cases without junk science. In others words, we sacrifice the presumption of innocence on the altar of something akin to scientific voodoo. We do this because of a concept with which psychologists are familiar: act hunger.
Only stones are unmoved by the sight of another's suffering. Every heart is inspired to act in the face of life's great tragedies. A deep-seated hope harbored by all is that of an orderly universe. We want things to happen for a reason. When things occur that inspire pity or horror, we want to restore the hoped for balance. That requires righting what was done wrong. In the criminal courts, that means assigning blame. Thus, when a child dies, there must be a culprit. In a secular age, we prefer a defendant as many of us have long since retired the Devil as an efficacious moral agent.
But acting merely to relieve an inchoate sense of threat is not justice. We should care as deeply about assigning legal guilt to people who have done nothing wrong. A disciplined criminal justice system would refuse to admit junk science at trial and leave the human tragedies that serve as the fodder for criminal trials unresolved. In other words, good courts reject junk science but frustrate the innate impulse to find a villain in every sorrow. The urge to act all too often yields an over reaction.
The next time a prosecutor intones that evidence is necessary to prove the state's case, I'd like a judge to say, simply: "What has that to do with justice?" Let's face it: sending a person to prison for decades rarely accomplishes anything.
Reprinted courtesy of the Connecticut Law Tribune.