The American system of justice is designed to be adversarial. Two sides do battle and a judge or jury decides which side has the better case. To prove their cases, parties often rely on expert witnesses.

The system works reasonably well, but arguments are occasionally made that justice would be better served by relying on “neutral” or “independent” experts who, having been appointed by the judge, would not feel the need to slant testimony in favor of whichever party hired them. Whether that proposal would actually lead to better results is open to question.

Appointed Experts

The Federal Rules of Evidence allow a judge to appoint an expert, with or without the consent of the parties, in both criminal and civil cases. The rule’s explanatory comment states that the rule is meant as a counterweight to the practice of “shopping for experts.”

Of course, the adversarial system anticipates that parties will present evidence that helps them prove or disprove a claim. Finding experts who have something useful to contribute to the jury’s decision should not derogated by the phrase “shopping for experts.”

Judges rarely appoint their own experts because they don’t want to interfere with the fundamental nature of an adversarial system of justice. Judges are understandably reluctant to impose an expert witness on lawyers when the lawyers believe they have chosen experts are better suited to provide expert opinions to the jury.

Judges who have faith in the adversarial system tend to understand that experts frequently disagree, not because they are being paid, but because science is often inexact. Disagreement among experts is nearly inevitable when the subject matter of their testimony is complex, and who is to say that a court-appointed expert is more likely to be correct than one hired by the parties?

A study by the Federal Judicial Center found that federal judges rarely appoint their own expert witnesses. Judges expect the adversarial system to work and they don’t want to influence the outcome of a case by appointing an expert who may benefit one side more than the other. Judges are also concerned about forcing parties to pay for an expert they don’t want or can’t afford.

Complex Issues

Judges may be more inclined to appoint an expert to assist the court when the case will not be resolved by a jury and when issues are complex. In child custody disputes, for example, the court might appoint a psychologist to determine whether one parent would be a better custodian than the other.

Judges who are asked to resolve disputes that involve complex scientific or technical issues might also appoint an expert. Engineering experts are appointed to help courts in cases involving patents and trade secrets, while accounting experts may help judges determine damages in commercial cases. Less often, judges appoint experts in medical malpractice, product liability, and toxic tort cases. Since those cases are usually resolved by juries, however, judges are reluctant to interfere with the trial by insisting on a judicially-appointed expert.

Judge Richard Posner, one of the brightest and most controversial judges on the federal Court of Appeals, has long advocated the appointment of “neutral” experts to educate juries about technological or commercial issues that jurors (and judges) are unlikely to understand. While other commentators — including some experts and judges — have jumped on that bandwagon, the bandwagon is moving slowly and may never reach its intended destination.

Controversial Suggestions

Advocates of court-appointed experts tend to distrust the adversarial system. Sometimes that distrust is rooted in trial outcomes (such as verdicts against big businesses or insurance companies) that are unfavorable to the advocates. Others see those outcomes as proof that the system works just fine.

Distrust of expert testimony has been strongest in cases involving drugs that are alleged to cause health problems and toxic substances that are alleged to harm people who live in a particular area. Businesses and insurance companies, unhappy with the verdicts that juries returned against them, insisted that those allegations were supported by “dubious causation theories,” a concern that gave birth to the Daubert standard. Only experts who have formed opinions using a reliable methodology may testify under Daubert.

Whether judges are capable of evaluating the reliability of a scientific methodology is an open question. Judges are not scientists. As Justice Breyer noted in a concurring opinion, some scientists have suggested that judges should appoint their own experts to help them evaluate the reliability of a party’s retained expert. Yet how is a judge to know that an appointed expert is less biased or more capable than a retained expert?

Perils of Neutrality

When an expert serves the court rather than a party, the expert is said to be neutral. But no expert should be an advocate for anything but the truth. The same is true of judges. If there is a risk that an expert will habitually favor one side in a dispute, that risk may exist whether the expert is retained by a party or judicially appointed. After all, judges are often seen as being “liberal” or “conservative,” and their biases may incline them to appoint experts who share the same biases.

If judges feel the need to appoint experts, they might want to select the experts from a list that has been assembled by the relevant scientific community. That suggestion might overcome the fear that judicial bias would lead to the appointment of a biased expert. But if the group that assembles the list has a bias, a judicially-selected expert may be just as partisan as a retained expert.

When judges do appoint experts, should the jury know that the expert was selected by the court, not the parties? The risk is that juries may place undue reliance on an appointed expert in the belief that “the judge’s expert” must be more reliable than the retained experts. Even if jurors are not told that an expert was court-appointed, the fact that an expert isn’t working for either party is often easy for juries to discern.

Cross-Examining an Appointed Expert

An appointed expert should be subject to cross-examination just like any other expert, but some lawyers fear that a “tough” cross-examination of an appointed expert might incur the wrath of the appointing judge. Fear that upsetting the “judge’s expert” will upset the judge might lead to a timid cross-examination, but the adversarial system requires lawyers to be vigorous as they probe experts to expose the strengths and weaknesses of their opinions.

Since a jury might attach more weight to the opinions of the “court’s expert,” lawyers who cross-examine the expert should look for common ground in the analysis of the appointed expert and that of the party’s retained expert. The best strategy might be to emphasize points of agreement while suggesting that disagreements between the experts are minor. And since expert opinions depend on the facts, the appointed expert might be willing to concede that his or her opinion could change depending on which party’s version of the facts the jury accepts as true.

In the end, skilled advocates in an adversarial system can only do their best to help juries find the truth. Sometimes the system works and sometimes it doesn’t, but it is far from clear that the routine appointment of expert witnesses by courts would improve the accuracy of jury verdicts.