Convicting with Junk Science

There have been a whole lot of criminal convictions in the United States based on what prosecutors and the courts have held to be “hard scientific evidence,” where the evidence was neither hard nor scientific. The original standard for the scientific systems in criminal trials – generally accepted and established principals of science – was established in 1923 in a District of Columbia circuit blood-pressure-measuring “lie detector” case, Frye vs. United States. This standard is still the prevailing standard in many states, even though in 1993, the U.S. Supreme Court replaced Frye with Daubert v. Merrell Dow Pharmaceuticals in federal actions.

Applying the Federal Rules of Evidence (particularly section 702), Daubert repeated the rule stating: “If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise…” Specifically, the requirement of “knowledge” and that it would actually help the jury (or judge as a trier of fact when a jury trial is waived) come to a decision based on the relevant opinion. The court has to screen such testimony and physical evidence before it is presented, and that something is “generally accepted” is no longer the standard. The court went one step further in noting the ever-changing nature of scientific research and standards and that what was once taken for granted often later is rejected as unfounded.

Forensic-Evidence.com notes that once reading the bumps on a subject’s head was assumed to be an accurate way of assessing human traits and behavior: “Phrenology was defined as the science ‘devoted to the identification of basic brain functions and their manifestations in cranial features.’ While in modern times we may "think of it as harmless quackery practiced upon the gullible at country fairs,’ . . . in 1840, phrenology was a confident science, promising clear and certain knowledge concerning the mental attributes and behaviors of human beings. . . . There were conferences and symposia. There were professional associations. There were lengthy learned tomes and scholarly journals. The first issue of the American Phrenological Journal had just appeared in October of 1838.@ Phrenology's basic principles were established be the renowned Dr. Franz Joseph Gall. [See, Pierre Schlag, "Commentary--Law and Phrenology", 110 Harv.L.Rev. 877 (1997).]”

Calling something scientific under the mantle of court-approved evidence carries a lot of weight with a jury. Take this example cited in the December 24^th New York Times: “Undigested bits of mushrooms and tomatoes from Christine Morton’s last meal — a celebratory birthday dinner she had with her husband — were still in her stomach when the medical examiner performed his autopsy in 1986… Those remnants, the prosecutor told the jury during Michael Morton’s trial, “scientifically proved” that Mr. Morton had beaten his wife to death… Twenty-five years later, DNA science revealed that someone else had actually killed Mrs. Morton and that her husband’s murder conviction and more than two decades in prison were a tragic mistake. His exoneration based on DNA evidence is the 45th in Texas…

“‘What passes for science in courtrooms is not always, in fact, science,’ said Kathryn Kase, interim executive director of the Texas Defender Service, which represents death row inmates… In recent weeks, the Texas Court of Criminal Appeals has agreed to review cases that indicate it may also see a need to address the types of evidence that meet scientific standards… In November, the state’s highest criminal court agreed to review the case of Megan Winfrey, who is serving a life sentence for murder. She was convicted largely on the testimony of a sheriff’s deputy who said his bloodhounds ‘alerted’ to her scent on the murder victim’s clothing. The court has previously ruled that dog-scent evidence, used to convict Ms. Winfrey’s father for the same murder, was insufficient without corroborating evidence. The court acquitted her father on appeal.”

It’s pretty easy to sway a jury with “scientific evidence,” and thus when someone’s life or liberty is at stake, we owe them a vastly higher quality of evidence. After all, the ultimate standard in a criminal conviction is and must remain “beyond a reasonable doubt,” and questioning every bit of evidence at all times is an essential part of that process.

I’m Peter Dekom, and to give us confidence in our system of justice, we must always question its process on a never-ending basis.