King Trial May Come Down to a Case of Expert vs. Expert : Testimony: Specialists for both sides have taken the stand. Credibility of witnesses could be deciding factor.

When a defense attorney announced plans last week to introduce yet another expert witness--this one to testify about a computerized three-dimensional re-creation of the Rodney G. King beating--Judge John G. Davies was hardly surprised.

“I’m sure it’s all marvelously done,” the judge remarked.

And when a prosecutor jumped up to object, declaring: “We have an expert (who) says it’s imprecise,” Davies was not surprised, either.

“That expert will testify and debunk the whole thing, right?” the judge asked Assistant U.S. Atty. Steven D. Clymer, who dutifully nodded.

So it has gone for much of the last five weeks in U.S. District Court, where four Los Angeles police officers face charges that they violated King’s civil rights when they beat him into submission March 3, 1991. Although the emotional testimony of King and a few others has drawn the most attention, the trial has been consumed largely by an almost numbing parade of expert witnesses. At times, the proceeding has looked more like a medical malpractice case than a criminal trial stemming from a gritty street confrontation.

With the stunning decision of defense attorneys Thursday to rest their case after calling only one defendant, Sgt. Stacey C. Koon, to the witness stand, the outcome could well hinge on how jurors view the competing medical and police experts who have tried to mold their views on most of the key issues before the panel:

Was King struck in the head with police batons, or were his facial fractures caused by a fall to the ground? Did the officers have reason to believe that King was crazed--and inhumanly strong--from taking PCP? Were the baton blows a gross violation of police policy, or a textbook use of force by officers whose tools were limited by politicians’ decisions and haphazard training?

From the start of the case, defense attorneys--encouraged by the outcome of last year’s state trial in Simi Valley--made no secret of their hope that a barrage of conflicting expert testimony would, at the very least, create “reasonable doubt” in the jurors’ minds.

As Harland W. Braun, who represents Officer Theodore J. Briseno, put it: “Your experts really don’t have to be better than their (the prosecution’s) experts. All you’ve got to have are experts on both sides. I think (jurors) wonder: ‘How could we as lay people know beyond a reasonable doubt, when the experts can’t decide?’ ”

The experts on both sides have come with a colorful array of props, from a plastic foam head and two skulls to fire-engine-red body armor. To illustrate their points, they have wrestled in front of the witness stand and sprawled on the courtroom floor.

Some have come from the medical world, lecturing the jury on eye socket wounds, the meaning of a speck of gravel embedded in King’s face and how the jolt of a Taser affects enzyme levels in the body. This group also produced competing skulls--after a prosecution doctor used a plastic replica to detail King’s injuries, his defense counterpart showed a film in which the fractures were outlined on a real skull.

From the police ranks, experts have testified about chokeholds and “swarm” techniques, on “static” versus “dynamic” baton training and on how cops often confuse basic facts of violent incidents, including whether they shot someone in the chest or the back.

Davies has played the role of bemused referee amid the conflicting accounts, which often resemble a game of one-upmanship, such as when a specialist in baton techniques revealed that he had first been solicited by prosecutors before defecting to the defense camp.

“So the government thought it had a live one and it turned out they didn’t,” Davies remarked outside the presence of the jury. “It happens all the time in this business of expert shopping.”

In many other countries, courts do not endure such battles of experts. If there is a technical issue to be decided--perhaps a defendant’s sanity--the judge appoints one outside expert to serve as an adviser to the court.

But in the United States, with its fiercely adversarial system, the use of experts has become big business, giving rise to medical and engineering consulting firms that provid fancy court exhibits and well-trained witnesses who can earn hundreds of dollars an hour. Such experts are usually associated with civil trials because “there are large dollar amounts involved,” said Myrna Raeder, a professor at Southwestern University School of Law. in Los Angeles.

But in the criminal realm there also is much to be gained by using experts, Raeder said. She cited the trial of William Kennedy Smith, a nephew of U.S. Sen. Edward M. Kennedy, which featured experts on such details as the type of grass behind the Kennedy estate in Palm Beach, where he was accused of raping a woman.

“Your limitation on use of expert testimony,” Raeder said, “is only how imaginative you are.”

In the first King trial, Los Angeles County prosecutors seemingly believed that the videotape of the King beating spoke for itself.

But defense attorneys argued that this was no normal assault case because the accused officers were trained and authorized to use force. Thus, they called a series of witnesses to explain police practices, most notably Sgt. Charles L. Duke Jr., a burly SWAT team leader who guided the jury through the videotape while providing his interpretation: The pictures widely viewed as police brutality, he said, actually showed officers doing what they were taught to do.

Only in its rebuttal case did the prosecution scramble to respond with its own use-of-force expert, Cmdr. Michael Bostic. But he had little street experience and, in the eyes of many spectators, was not as impressive as Duke.

Some legal scholars chastised prosecutors for not vigorously contesting the admission of expert testimony on use of force, calling it a strategic decision of perhaps even more importance than not calling King as a witness. These observers said the government could have argued that the issue of whether the officers used unreasonable force was a matter for the jury to decide and should not be subjected to expert analysis, which is generally reserved for scientific or technical questions.

“I thought they made a horrible mistake,” said New York attorney Harvey Weitz, who monitored the state case for the Courtroom Television Network. Once the jurors were exposed to the testimony, Weitz said, they concluded: “Who am I to second-guess?”

Several of the Simi Valley jurors confirmed his speculation after they returned the not guilty verdicts that ignited last year’s riots.

“This case has shown everyone has different perspectives,” a juror said. “The judge’s notes--our instructions of how we could consider evidence--stated . . . if there are two reasonable explanations for an event, we had to pick the one that points to innocence, not the one that points to guilt.”

To avoid a reprise of the Simi Valley verdicts, federal prosecutors this time were determined to beat the defense to the punch--a move that set up a series of confrontations and swings in momentum in the war of experts.

The federal prosecutors struck first by dropping Bostic as a use-of-force expert and summoning the more streetwise Sgt. Mark John Conta, who spent 17 years patrolling Los Angeles. Leading the jury through the videotape--much as Duke had done for the defense a year earlier--Conta told jurors that the officers acted in “clear violation” of LAPD policy.

Though called to speak as an expert, Conta also raised an important prosecution theme, that “expert” opinions should not replace common sense when viewing the videotape. Responding to a defense argument that the officers had never been formally trained in a “swarm technique”--which might have enabled them to subdue King without clubbing him--Conta remarked: “I did that technique in 1972. . . . An individual told me: ‘Grab a leg.’ . . . What training would you need?”

When it came to medical testimony, the federal prosecutors did not rely only on emergency room physicians who examined King after the beating and who were unable, during the state case, to say what caused his head injuries. Instead, they produced two medical experts who had examined X-rays, CAT scans and other records on King. They concluded that his injuries were caused by police batons.

The government this time also aggressively sought to impeach and embarrass the defense experts. Prosecutor Clymer repeatedly challenged their credentials and appealed to Judge Davies to limit their testimony by ruling out broad, preachy opinions that invade “the province of the jury.”

But Davies gave the experts wide leeway, expressing confidence that the jury would be able to spot dishonest posturing. “You underestimate the jury and its ability to sort these things out,” the judge said when prosecutors tried to cut off one line of questioning.

The prosecution’s bid to undermine the opposing experts suffered a severe blow when the defense produced a former Wisconsin police chief, Edward Nowicki, who trains officers in the use of batons. The encounter demonstrated the considerable perils in the expert-witness game.

Nowicki disclosed on the stand that the prosecution had flown him to Los Angeles last year, figuring that he might be a good witness for them because he had reacted with “outrage” to the King beating. Nowicki said he changed his opinion when prosecutors showed him the full videotape, deciding that the baton strikes “were absolutely appropriate.”

Prosecutors pleaded with Davies not to allow testimony about Nowicki’s flip-flop, complaining that it could prejudice the government’s case. But the judge allowed it, issuing his warning about the dangers of “expert shopping.”

Clymer then challenged the credentials of the man the government had considered using. He got Nowicki to acknowledge that he had been police chief of a small resort town--with fewer than 10 officers--and that the training standards he trumpeted were assembled largely by the baton manufacturer, which makes its money selling the gear and training services.

The prosecution launched its strongest attack when the defense introduced its final expert, Carley Ward, a biomechanical engineer. She testified that force tests using batons indicated that King could not have been struck in the head because such blows would have caused far greater injuries than were found on him.

In an extended cross-examination, Alan Tieger, the most soft-spoken and detail-oriented of the Justice Department lawyers, introduced evidence that an appeals court once reversed a conviction in a case where Ward testified for the prosecution, finding what he called “flagrant loopholes” in her procedures.

Stone protested introduction of the evidence, but Davies allowed it and delivered another lecture--this time directed at the defense--on the danger of using experts. He noted that Stone had raised the issue of Ward’s prior testimony by getting her to list all her qualifications, including the fact that she had testified in numerous trials.

“It’s the price you pay for gilding the lily,” the judge scolded Stone.

Tieger went on to belittle Ward’s work on the King case by comparing one of her test instruments, a “force plate,” to a bathroom scale. He asked Ward if it was true that her daughter had wielded the police baton in some of her tests.

Ward responded that her daughter weighed 150 pounds and was “one of those outstanding athletes very good at baseball.”

After the day’s testimony was complete, Laurie Levenson, a Loyola University law professor who has monitored the trial, said the brutal cross-examination might help to remind the jury “that there are experts and there are experts. “

Although observers of the legal system have noted the seeming absurdity of having supposed experts issuing diametrically opposite opinions, Raeder shares Judge Davies’ faith in the ability of the King jury to “figure this out . . . in terms of judging credibility.”

Times staff writer Jim Newton contributed to this story.

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