AFTER being tied up in the Arizona courts for 15 years, a double-murder trial appeared headed for another impasse. The jury was deadlocked after four days of deliberations.
Defying 200 years of jurisprudence tradition, Maricopa County Superior Court Judge Michael Dann tried a bold experiment. He opened a dialogue between himself, the jurors, and the attorneys in the case.
To address juror confusion, Judge Dann ordered the lawyers for each side to reargue the case for one hour. The procedure worked. After another three hours of deliberation, the jury returned an acquittal.
The willingness of judges in this Southwestern state to buck traditions - armed with the latest behavioral research - is putting Arizona in the vanguard of American judicial reform.
In December, the Arizona Supreme Court enacted a sweeping set of changes - such as allowing jurors to ask questions during a trial - designed to engage jurors more fully in the legal process.
Many of the reforms ''have a great deal of common sense behind them'' and are likely to be models for other states, says Marc Whitehead, a Minneapolis attorney and chairman of the American Bar Association's task force on juries.
Already, the Delaware Supreme Court is studying the Arizona experiment. California is also looking at reforming its jury system in the wake of the the O.J. Simpson murder trial.
A growing concern among judges is what Dann calls ''unacceptably low levels'' of understanding among jurors of legal procedures, rules of evidence, and court instructions. He recently wrote that juries often don't reflect today's diverse society and that there's a passivity among jurors that can weaken the judicial system.
In April 1993, long before the Simpson case raised similar jury reform issues, the Arizona Supreme Court established the Committee on More Effective Use of Juries - a panel of former jurors, academics, jury administrators, attorneys, and judges.
Arizona Chief Justice Stanley Feldman, who convened the panel, says that the review became necessary because the system was ''encrusted'' with procedures dating back 100 years or more. Those procedures, he says, were based on assumptions that social scientists have since proved false about how people process information and reach decisions.
''We've learned a lot about how people process information and decide things,'' Justice Feldman says. ''A lot of what we thought was so, is demonstrably not so.''
The panel produced a list of 55 recommendations. The state has adopted 18 of them, some of which allow:
* Jurors in civil cases to discuss evidence among themselves before deliberating.
* Jurors to ask questions in writing through the judge. The practice has precedent in the English jury system, which in the 1600s permitted jurors to ask questions during trials.
* Jurors to receive copies of jury instructions, trial exhibits, photos of witnesses, and other key documents.
* Judges to place time limits on trials and to assist deadlocked juries.
* Attorneys to make mini-opening statements before jurors are selected for a trial to help detect juror bias.
* Jurors to be instructed at the beginning, as well as the end of a trial, to improve comprehension of legal issues.
Feldman says the changes are aimed at making jurors active participants rather than passive observers.
The changes should produce ''trials that allow for a more democratic juror experience, ones that are more educational and less adversarial,'' the report said. ''Judges and trial attorneys are summoned to be open to ... actively participate to a greater degree in the fact-finding process.''
That has been difficult in the past, Feldman says, noting, ''A lot of trial judges are hesitant about doing new things unless the rules specifically authorize them.''
One of the most significant - and controversial - reforms is one that allows jurors to discuss evidence among themselves in civil cases before deliberating. Under traditional procedures, jurors are instructed not to discuss a case until deliberations start. But the panel said the ban was ''anti-educational, nondemocratic and not necessary to ensure a fair trial.''
BEHAVIORAL researchers say that a juror's natural tendency is to actively process information as it is received as well as afterward, thus forming tentative judgments about evidence.
And research shows that up to 44 percent of jurors ignore the judge's warning and discuss evidence among themselves.
But the ABA's Mr. Whitehead opposes the reform. He says studies indicate that people hold on to an opinion after having publicly expressed it, thereby interfering with a ''holistic discussion that we like to see at the end of a trial.''
Judge Dann, a leading proponent of legal reform, says the matter boils down to trusting jurors' judgment. Jurors, he says, know and respect the difference between sharing evidence during trials and reaching a conclusion prior to deliberating.
''It takes time to change a culture,'' he says. ''Some of these changes frighten some judges because it means more decision points, more work, more discretion exercised, and they know that sound discretion is required.''