Aug 12, 2008

Expert Witnesses: Should They Be in Hot Water?


Is a defendant mentally competent to stand trial? How credible is an eyewitness' identification of the defendant as the perpetrator of a crime? Did the DNA testing lab correctly perform the analysis linking the defendant to blood found at the crime scene? Is this the defendant whose voice is on the recorded bomb threat?

For answers to these and myriad other questions that arise daily in criminal trials, judges and lawyers typically turn to expert witnesses. To jurors, however, the answers are often more mystifying than enlightening. It's not just that the subjects that experts testify about are unfamiliar and complex. Often, the reason is that each side -- prosecution and defense -- presents its own expert, and the experts flatly contradict each other. Had Sir Isaac Newton been writing about the U.S. trial process rather than physics, he might have written: "For every expert opinion there is an equal and opposite expert opinion."   

The problem is that experts are part of the adversarial trial process. Each party hires its own expert, who can be counted on to deliver opinions that support the party paying the expert's fee. Indeed, if one or two experts disagree with a party's position, the party can shop around for one who will sing the correct song in court. No wonder jurors often have to throw up their hands and side with the expert "who looks and sounds like the experts on TV courtroom programs."     

Various solutions to the problem of trials turning into Battles of the Partisan Experts have been proposed. A frequent idea is for judges to appoint so-called Impartial Experts. But attorneys are loath to give judges control over crucial aspects of their cases, and anyway, experts can't be counted on to be any more impartial than the rest of us. The reality is that the answers to scientific and technical questions are often uncertain and even unknowable, and experts can disagree without fudging the truth as they perceive it.

"Hot tubbing" may be the way to go -- developed in Australia, hot tubbing consists of having opposing experts testify together, in conversation with each other. Hot tubbing is consistent with many current courtroom procedures, such as each side retaining its own experts. And lawyers and judges are able to put questions to the experts as they testify. But while they are in the figurative hot tub, experts can respond directly to each other, and often can find some common ground.  As a result, jurors may better understand their testimony and arrive at more educated verdicts.

Whether hot tubbing will catch on here in the U.S., and its effectiveness for advancing the truth-seeking function of trials, is uncertain. However, solutions to the perceived problems inherent in partisan expertise have been hard to come by, and hot tubbing is an alternative that holds promise.