The Arizona Court of Appeals has quashed a new law designed to limit who can testify as expert witnesses less than a year after business groups got state lawmakers to approve it.
In a unanimous decision, the judges said the statute improperly and unconstitutionally usurped the power of courts to adopt their own rules. In fact, Judge Philip Espinosa said the measure approved last session effectively repeals existing rules adopted by the Arizona Supreme Court.
The decision is a major setback for the Arizona Chamber of Commerce and Industry, which convinced lawmakers to approve the change. Lobbyist Marc Osborn said he expects the case eventually to wind up before the state Supreme Court.
Central to the issue is who gets to testify as an expert.
A standard adopted by the U.S. Supreme Court nearly a century ago says the test is whether the testimony is based on science that has gained “general acceptance’’ in the relevant field.
In 1993, however, the nation’s high court adopted a more stringent test.
It requires a judge, in determining whether to let someone testify, to consider whether the theory has been or can be tested. Other factors include whether the theory has been published or subject to peer review and the known or potential rate of error of the technique or theory.
Business interests, particularly those in product liability cases, like this test. Proponents said the more lax rules allow for the introduction of “junk science’’ that can sway jurors in favor of someone seeking to recover damages.
Arizona courts, however, never adopted the new rule. But last year lawmakers forced the issue, spelling out in statute that same more stringent standard in determining who can testify in Arizona courts.
This case, the first appellate decision on the issue, involves who can testify in a criminal case about the effects of child abuse.
The defendant challenged an expert prosecutors sought to call, arguing that her testimony does not meet the new standards. But a trial judge ruled — and the appellate court agreed — the Legislature lacked the power to enact that new standard.
Attorney Barry Halpern, who helped craft last year’s legislation, said he thinks the judges got it wrong in concluding that lawmakers were interfering with the exclusive rights of the courts.
“The statute was drafted to inform and advise the court, but not to direct a specific result,’’ Halpern said.
He pointed out that the law spells out only what a judge should consider in determining whether a witness is qualified to testify as an expert. Halpern said the ultimate decision, though, remains with the judge.
Halpern also said that even if the Legislature is “supplementing’’ judicial rules, that does not violate the separation of powers between the legislative and judicial branches of government.
Osborn said the question, at least from the perspective of the courts, may be one of turf.
“It gets to the fundamental issue that ‘we don’t like the Legislature playing in our sand box,’ ’’ he said.