One fall evening three years ago, Pedro Jose Gil watched police arrest a group of his friends following a loud argument over double-parked cars on their Manhattan street. He then climbed six flights of stairs to the roof of his apartment building, peered over the ledge, and saw police cruisers start to drive away with his friends inside. He picked up a bucket of spackling compound and heaved it over the edge.
Gil was angry. He wanted the bucket to make a loud noise when it hit the sidewalk and scare people, he would later tell his lawyer.
Instead, the bucket arced out toward the road and struck police officer John Williamson on the head. Williamson would die from the blow within hours. Gil fled. Three days later he surrendered to police, and was charged with second-degree murder.
Several months later and 200 miles southwest, in a white-walled Homewood office at Johns Hopkins, Michael McCloskey's midday contemplation of cognitive neuropsychology was interrupted by a phone call from attorney Peter Neufeld. Neufeld was representing Gil, and he believed that his client, who had no criminal record, had not intended to hit Officer Williamson. McCloskey had the expertise that might help Gil's defense, Neufeld said.
It was not unusual for McCloskey to receive calls from attorneys. Research he had conducted previously on the accuracy of eyewitnesses had brought one or two inquiries a year. But this call stemmed from an entirely different angle of the scientist's work, one he had wrapped up and filed away many years before.
McCloskey, a professor of psychology and cognitive science, is one of a handful of psychologists who have studied people's perceptions of everyday physics. In experiments reported in Science and Scientific American in the early 1980s, McCloskey discovered that people's intuitive beliefs about physics are often wrong. For example, most people believe that when a ball rolls off a cliff, it may travel horizontally at first, but will then plummet straight down--like Wile E. Coyote. The reality is that the ball will travel in a parabolic trajectory, continuously moving forward while traveling downward.
Attorney Neufeld was interested in the inference that could be drawn from McCloskey's research. Given this widespread misconception, Neufeld thought, it was reasonable to conclude that most people aiming for a target several stories below would overshoot. Assuming Gil's sense of physics was like most people's, if he were aiming at the sidewalk, he could well have overshot his mark and accidentally hit the officer.
McCloskey hesitated to participate at first. He had not done research in this area of psychology for several years. But after thinking about it, he decided to help. Whether or not Gil had intended to hit the officer was not for him to decide. That was the jury's job. But Neufeld's argument was plausible, McCloskey reasoned, and "the defense deserved this kind of help." He agreed to consult on the case pro bono, as Neufeld was doing.
The outcome of The People of the State of New York vs. Pedro Gil could hinge on McCloskey's testimony.
For McCloskey and dozens of other Hopkins faculty members, serving as an expert witness is a chance to emerge from the ivy-covered in vitro setting of the university and demonstrate their knowledge in a wider context.
Though Hopkins scholars have been sharing their expertise from the witness stand since the last century (see " Experts From the Annals," p. 47), the use of expert witnesses has mushroomed over the past 20 years, as everything has become more complicated. "The experts need to bring complex topics into basic English," says Chicago attorney William Deitrick '67, who regularly depends on expert witnesses.
Research institutions (including Hopkins) are prime fishing grounds for lawyers seeking expertise. While high-profile cases such as the trials of O.J. Simpson and Jeffrey Dahmer have spotlighted the use of DNA experts and forensic psychiatrists, expertise can come from virtually any discipline. Hopkins immunologist Noel Rose has worked on cases involving autoimmune diseases; economics professor Bruce Hamilton has discussed anti-trust law as it applies to professional football; environmental engineer Ed Bouwer testified about pollution and water quality. And these are just a handful of the many Hopkins experts who have consulted in legal cases.
Some academics refuse to serve as expert witnesses. "It's always struck me as slimy," says Hopkins chemistry professor Craig Townsend. Many do, though. There's the money, of course. "The pot of gold is clear at the end of the rainbow," says David Blum, a Baltimore attorney who this month is teaching a course at the School of Public Health on "How to Be an Expert Witness." Geared toward environmental professionals in the occupational health field, the course includes a section on how to market yourself. While some experts reportedly have been paid as much as $1,000 per hour for time spent preparing for a case, testifying in court, and traveling to get there, most fees are more modest. An engineer, for example, might earn $130 per hour.
But many academics who have served as expert witnesses say they are driven by duty, particularly if they are among the only authorities on the topic. "Sometimes legitimate scientists have to forgo the ivory tower, and tell the public what we know," says immunologist Rose.
For scholars who do take the witness stand, it can be a chilling baptism. In the academic world, the goal is truth in all its messy complexity, and scholars feel free to rethink their ideas and revise their theories. In fact, they're suspect if they don't. Scholarly discourse tends toward a leisurely back-and-forth, with efforts for clarity on both sides and at least a veneer of civility. There's time to think. "If someone comes into my office and criticizes my work, says I'm all wrong, I can go back to them tomorrow and tell them why they're wrong," says economist Hamilton.
Not so in court. "Cross-examination is far from the ideal way to get to the truth," says Hamilton. He has consulted on several anti-trust cases, including one in which athletes hired to practice with professional football players charged Pro Football, Inc., with unjust price-fixing of salaries. In that case, Hamilton was asked to calculate the damages owed to players. Litigation, particularly cross-examination, "is more of a game than an act of enlightenment," he's found. "I'm trying to make the opposing attorney look stupid, and he's trying to make me look stupid. It's point-scoring rather than getting to the bottom of the matter."
Wits match wits. Tactics anticipate strategies. Obscuring facts can win points. "You have an advantage if you can think fast," Hamilton says.
It's no wonder that some academics end up feeling like one of those square pegs being shoved into a round hole. "I never felt comfortable," says Arts and Sciences professor of psychology Howard Egeth, who consulted on more than a dozen criminal cases in the 1980s. "I don't have the personality to be a prosecutor or defense attorney. They end up committed to one side or the other. I tend to see shades of gray."
Egeth is not alone. Scholars and scientists like him often find that the truth lies somewhere between black and white. But "gray" doesn't fly so well in the courtroom, as environmental engineer Ed Bouwer discovered when he testified in two different cases. In the first case, a town wanted to double the discharge of a wastewater treatment plant to allow more homes to be built in the area. A citizen's group contested the plan, claiming that the increased discharge would make a local river inhospitable to wildlife.
Bouwer was retained by the citizen's group to examine how the increased output would affect the river's health, as measured by its dissolved oxygen level. State law called for a minimum level of 6.0 milligrams of oxygen per liter. Using a computer model he developed, Bouwer calculated the range of oxygen levels that would result if the plant's sewage output were doubled. The average level, he told the judge at the administrative hearing, would likely lie below the state's standard. The judge said that because of the uncertainty, Bouwer's results did not warrant stopping the plant's expansion.
"Here is the difficulty with expert testimony," says Bouwer--"the uncertainty. There's no appreciation for variability. If I go in and say 6.0, ping, that's good. But by giving a range, I was perceived as wishy-washy."
On another case, Bouwer was asked to determine whether material from an unlined landfill would leach out and contaminate groundwater. A developer had planned to expand a landfill, and claimed he did not need to construct a liner because a natural clay barrier already underlay the proposed construction site.
It was Bouwer's job to determine how far material from the expanded landfill would migrate through the soil. There were patchy areas of clay, but not enough to be called a barrier, Bouwer concluded. Based on the fate of other landfill sites, he told the judge that without a liner, groundwater contamination could occur.
In the courts, Bouwer has learned the word "could" can escape and take on a life of its own, like a fumbled football that no one can catch. "The lawyer for the developer kept asking, 'How do you know it's going to happen here?'" says the environmental engineer. "A hypothetical likelihood based on past experience is very difficult to communicate," he says. "It was very frustrating."
Despite their best efforts, some academic experts fail to sway the judge and jury. That can be a disappointing reality for academics convinced they have the truth on their side, like medical psychologist David Schretlen. Schretlen is an authority on malingering--not from personal experience, he notes with some humor, but from research on malingerers. In particular, he has studied how to tell true insanity from feigned.
Last year, the defense lawyers for a young man named Francisco Duran asked Schretlen, as well as Hopkins psychiatrist Jonas Rappeport, to evaluate whether the 26-year-old upholsterer from Colorado Springs had been sane in October 1994, when he fired 27 rounds of ammunition at the White House.
While Duran was awaiting trial in U.S. District Court in Washington, D.C., a team of expert psychologists and psychiatrists evaluated him extensively. Schretlen spent 15 hours with him, during which he administered a battery of psychological tests including several designed to spot malingering. He learned, among other things, that Duran believed an alien force was subverting the government and that he, Duran, had been appointed to battle the force and save the country. Afterward, Schretlen, Rappeport, and another psychiatrist on the case concluded without a doubt that Duran was a paranoid schizophrenic. "I believed he couldn't fully appreciate the criminality and wrongfulness of what he was doing," says Schretlen.
But the prosecution had its own team of experts. For each piece of defense evidence demonstrating Duran's mental illness, the prosecution's experts countered. The prosecution argued, for example, that Duran had never been treated for a psychiatric problem, therefore was sane.
In the end, the jury convicted Duran. When Schretlen learned of the verdict, he thought, "Duran won't be alone. There are lots of people like him in prison."
Michael McCloskey never even got his day in court. After agreeing to work on the Gil case, McCloskey suggested an experiment to replicate the conditions of the purported crime. So before Gil's trial, he asked 19 male volunteers to climb to the roof of a building roughly the height of the one from which Gil had thrown the bucket. With McCloskey on the roof and Neufeld on the ground, each volunteer looked over the ledge at a rectangular target on the ground 18 feet from the base of the building, stepped back, picked up a 20-pound bucket, and without looking tossed it over the edge.
Sixteen of the 19 men threw the bucket beyond the target, on average eight feet past the rectangle. Further, 10 of those 16 men had predicted that the bucket landed short, and four thought they had hit the target. The results of the experiment supported the defense's argument; that Gil had unintentionally overshot the sidewalk, hitting the policeman by mischance.
McCloskey included the details and results of the experiment in his report to the Supreme Court of the State of New York. But he never testified. Prior to the trial, the judge barred his evidence on the grounds that it was irrelevant. Gil was convicted of manslaughter in the second degree, which carries a 5 to 15 year sentence.
Thinking back to the judge's conclusion, McCloskey tries to remain impartial, as he says an expert should do. "To the extent I understand legal issues, I thought the test should have been admitted. But I'm not a legal expert." If the case is appealed, however, he will testify.
With the gamesmanship inherent to the courtroom, expertise can end up taking a backseat to other more superficial factors. In the university setting, whether you wear an Armani suit, speak with crescendo, or gesture persuasively does not affect the outcome of your experiment. In the courtroom, appearances do matter. A lot, says Deitrick, the attorney.
"I, as a lawyer, am scripting a play in front of a judge and jury," he explains. "I have a certain slant in selecting how a story is told, the content, the order of the witnesses. And I come in in the end and say, 'Here's the moral.'" As the "director," Dietrick says he can handpick the experts who fit the part--people who have the proper appearance, demeanor, and tone of voice, and who make eye contact. That's something he can't do when dealing with clients and other witnesses. "Unfortunately, someone could be very ugly, and the jury will say, 'Gee, this person is ugly,'" and be less sympathetic.
Some academic experts rise to the challenge of the game, or drama, quite well. Immunologist Noel Rose, for instance, managed to hold his own when a querulous prosecutor set out to paint him as a selfish mercenary.
Rose has testified for the defense in several recent suits brought against silicone breast implant manufacturers by women who claimed that implants triggered their autoimmune illnesses. An authority on autoimmunity, he reviewed the results of a dozen epidemiological studies on the association between implants and autoimmune illness. He concluded there was a negligible risk of such illness from silicone implants. He also tested diagnostic tests that were being marketed as tools for detecting silicone or its breakdown products in the blood. He found that the test results always came back positive, whether he applied the tests to blood samples from women with autoimmune illness or from healthy women. "These tests have nothing to do with silicone," he says. "It's just another way of milking women of their money."
But when it came time to testify, the prosecuting attorney did not stop at Rose's scientific conclusions. He also tried to attack the scientist's integrity. At one point, the following interaction occurred:
Rose: I have no idea. I went to the courtroom. I said there what I have said elsewhere and then got on the plane and returned home.
Later in the trial, the attorney questioned Rose about the source of his funding. Rose first explained that he never accepts a fee for his services as an expert witness, and that he tells the attorneys he works for that they can contribute the amount he would otherwise be paid to a fund for immunology research at Hopkins. He continued: "And if you would care to support our research, I would be pleased to accept your money. In fact, I would urge you to do the studies if you honestly believe that breast implants are causing autoimmune disease. I would implore you to do the studies and show it. I would be the first to publish your paper." The lawyer paled, says Rose, and quickly changed the topic. "He was shocked at the thought."
Of course, being an expert witness has its advantages, or no one would do it. "I regard the expert witness role as an extension of my research," says Rose. For example, in a current case a group of Texas citizens alleges that contaminants from an oil refinery have leaked into groundwater and triggered cases of autoimmune disease. As an expert witness for the plaintiffs, Rose is conducting an epidemiological survey to see if there is an increased rate of autoimmune disease among the people in the region. "It's a great opportunity for me," says Rose. "We know that half of autoimmunity is genetic. We don't know what is responsible for the other half." He gestures toward a mountain of white papers next to his desk, the medical records of plaintiffs in the Texas case. "This may be nothing or it may be important as far as triggers of lupus go." The Texas study, he says, may reveal new compounds that can trigger autoimmunity.
For economics professor Bruce Hamilton, stints as an expert witness have spun off whole new areas of research and teaching. On one of his biggest consultancy jobs, Hamilton worked as an expert for an independent service organization that charged IBM with violating anti-trust laws. The organization was in the business of buying computer parts from IBM and using them to upgrade smaller IBM computers into mainframes. "They were cheaper than IBM and quicker," notes Hamilton. But then IBM refused to sell the group parts, which left consumers with only one place to upgrade their computers: IBM. This business practice, in which a company ties the sale of a durable good to the sale of replacement parts and repair and maintenance services, is called "tying," explains Hamilton.
The service organization sued, and won. Hamilton's role was to determine how much money the organization lost as a result of IBM's monopolistic practices. In his deposition, he reported that the damages came to several million dollars. While Hamilton's involvement in the case ended with his deposition, the pay-off to his research came later, as he began to investigate the larger issue of tying, in particular as it applies to the auto industry. Through his work on the IBM case, he says, "I stumbled into a new and exciting area of research."
He says his legal experience has also benefited his teaching. Through the anti-trust cases, he worked with and got to know Washington attorney Robert Levy. The two then developed and now co-teach an undergraduate course on anti-trust law. In their lectures, they discuss their personal experiences in the court system, says Hamilton. The effect, he says, is to bring the world of law into the classroom.
So the circle closes. As academics feed the judicial system's hunger for expertise, the courts, in turn, provide the classroom and scholar food for thought, with pitfalls and promises at both ends.
Melissa Hendricks is the magazine's senior science writer.
Experts From the Annals
Excerpted from "Hopkins Pastimes," a series of reader recollections that appeared in issues of Johns Hopkins Magazine published in 1976, the centennial year.
A rejected lover, on hearing that his girl was to marry another, had fashioned a pipe bomb, which he mailed to the prospective bride as a wedding gift. As it was being unwrapped, the bomb exploded and one or two people were killed and others injured.
Fragments of the pipe were gathered by police, and R.W. Wood was consulted in order that the bits could be identified as parts of secondhand pipe that the murderer was known to have purchased some weeks before. Wood's testimony was very compelling, so much so that defense counsel felt obliged to be incredulous, and to convey his incredulity to the jury.
On cross-examination, therefore, he held up one of the tiny pieces of metal and asked sarcastically, "Do you mean to tell me that you can identify an object as tiny as this, and declare it to be a piece of a specific kind and size of pipe?" Wood said that he could. The lawyer turned to the jury and, in waving his arms, dropped the bit of metal on the dark carpet.
The fragment was a marked exhibit and therefore important, so there was a big scramble to find it. Finally, defense counsel found the fragment, or thought he did, and again truculently demanded to know if Dr. Wood could identify it. When Wood said he could, the lawyer belligerently asked, "Well then, what is it?"
Said Wood, "It's a mouse turd."
--Robert H. Roy '28
During the 1890s, the Niagara River was harnessed for power and Henry Rowland, a physicist and member of the founding faculty, was called in as a consultant. Asked for his bill, Rowland first replied that he was a man of science, not business, and that a fee was not necessary. When pressed, however, he did present a bill, for $25,000. The Niagara Company claimed this fee was exorbitant and refused to pay; Rowland sued. During the trial, the company's lawyer asked Rowland who the greatest physicist in America was. Rowland unabashedly replied, "I am." He won his case.
Later, when a friend teased him about being immodest, Rowland supposedly retorted, "My good friend, I was under oath."
Witness on Eyewitnesses
Bailiff: "Do you so solemly swear to tell the truth, the whole truth, and nothing but the truth?"
Witness: "I do."
Bailiff: "You may now lie down in the MRI."
Imagine this: One day before testifying in court, eyewitnesses undergo a magnetic resonance imaging (MRI) test. The results help the jury decide how good the witness is at remembering faces, and, thus, how reliable the witness's testimony will be.
No such scenario has played out yet, but Hopkins medical psychologist David Schretlen is planning experiments to see whether age affects an individual's ability to distinguish between, and remember, unfamiliar faces. Using MRI, he's looking at brain structures that may deteriorate with age. The health of such structures may correlate with a person's ability to remember faces.
Using MRI as a screening tool in the courtroom is admittedly extreme. "I think it's highly unlikely judges would allow us to run MRIs on eyewitnesses," says Schretlen, whose own work as an expert witness sparked his interest in eyewitness research. However, he says, a lawyer might be allowed to ask him to testify about his results.
"Eyewitness evidence is remarkably powerful and persuasive," Schretlen has found. "When a victim says, `That man attacked me. I'll never forget that face,' juries are remarkably willing to believe the eyewitness based on how confident the witness is. And judges instruct juries to evaluate the witnesses on how confident they are."
But Schretlen wasn't so sure that confidence and accuracy go hand-in-hand. So last year he asked 100 police officers to watch a video reenactment of a carjacking. The officers saw the film three times, including once in slow motion. They were then asked to examine a photo array and, if any of the photos matched the carjacker, to identify the culprit. Finally, they were asked whether they were confident they had chosen the right person.
Overall, the officers performed slightly better than chance. However--and this is a key point--the officers who were confident about their choice performed no better than the officers who were not confident. "That highlights something reasonably well-known from the literature," says Schretlen. "Eyewitnesses' confidence and their accuracy involve two different processes."
Under some circumstances, confidence does correlate with accuracy, notes Schretlen. If the crime occurred in a well-lit area, for example, and the witness identified the alleged culprit soon after the crime, then the witness's degree of confidence during court testimony can correlate with accuracy. It is the murkier situations--involving a poorly lit crime scene, a brief encounter between the witness and alleged criminal, a long lapse of time between the crime and the identification--that muddle the memory of a face, but not the confidence of the witness.
Many judges are not willing to allow such evidence in court, however. Schretlen has twice been barred from testifying about eyewitness reliability.
"It is still too early to testify about many of these factors in a courtroom," says professor of psychology Howard Egeth, who has written several papers critical of the use of psychological testimony about eyewitnesses. Egeth has found that the majority of studies on eyewitness reliability show conflicting or ambiguous results.
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