Volume 1, November 2001
“The Evolving Role of Scientific
Experts in the Courts”*
an invited lecture at Hillsdale College, September 14, 2000.
Program on Scientific Freedom, Responsibility and Law American Association for
the Advancement of Science
Criticism of the way the courts have handled--or
mishandled--cases that have involved complex scientific and technical evidence
has received extensive coverage in the press.
One might argue whether such coverage has exaggerated the problem, but
it nonetheless has created a degree of uneasiness with our judicial system. As the distinguished members of the Carnegie
Commission on Science, Technology and Government reported several years ago,
"If these claims go unanswered, or are nor dealt with, confidence in the
judiciary will be undermined as the public becomes convinced that the
courts…are incapable of correctly resolving some of the most pressing legal
issues of our day."
Part of this problem does rest with the judiciary, but part lies with
scientists and engineers as well. If
the integrity and image of science in the courtroom is to be enhanced, at least
two things have to happen. One, the
courts need to improve their ability to assess scientific and technical
evidence; and two, there needs to be a way for scientists and engineers to
provide their expertise without having to compromise their objectivity and
Why is science and engineering increasingly important in the
legal system? First, there the increasing presence of scientific and technical matters
in civil and criminal litigation means that the legal system requires the best
science in order to make rational decisions. Second is the singular critical role that scientific
evidence may play in certain types of cases. For example, in cases the rest on whether or not exposure to a chemical
led to crippling medical condition, science might be used to answer the question
of causation. For the parties, the failure to secure the admissibility of their
expert scientific evidence could mean the difference between winning and
losing. Third, as many death row cases
indicate, science can play a critical role in life and death decisions made by
our judicial system (e.g., DNA fingerprinting). Fourth, the economic stakes are high. Companies have filed for bankruptcy during the course of
litigation; high tort awards to plaintiffs can lead to higher consumer costs;
and companies may avoid innovation because of the risks associated with
litigation, thereby denying consumers new products. And fifth, there is a real danger that public confidence in the judicial system
and in the credibility of science is threatened by the way that legal system
deals with scientific and technical issues. This is manifested by the expert as
“hired gun” phenomenon and the public perception that the legal system does not
do an effective job of distinguishing between the Nobel Laureate and charlatan.
It is fair to say that there is plenty of blame to go
around. The point is that the courts
are seen as not having performed adequately in the way they have handled
scientific and technical information, and this mishandling has been blamed
for outrageous tort awards and improper criminal convictions.
The issue of science in the courtroom has been addressed by
a series of three Supreme Court decisions since 1993. They are Daubert v. Merrell Dow Pharmaceuticals, Inc., 509
U.S. 579 (1993); General Electric Co. v. Joiner, 522 U.S. 136 (1997);
and Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999).
three cases focused on the use of scientific and engineering-based evidence in
federal court. Essentially, they
instruct federal judges to act as gatekeepers in deciding whether to admit
scientific evidence, including expert testimony, into legal proceedings. Judges are expected to inquire into the
reasoning and methodology of underlying science and engineering testimony, and
into connection between evidence/testimony presented and conclusions drawn by
To put it succinctly, judges are asked to consider three
Is testimony based on established scientific or engineering
Are methods used appropriate to the task at hand and applied
Is there a logical connection between how the first two
questions are answered and conclusions drawn by expert?
There three cases have placed a heavy responsibility on
judges. For some, it’s a daunting task,
as reflected in these words by a federal district court judge. “I’ve got a background in the
humanities. And I’m faced with two
equally qualified scientists, one of whom says ‘black’ while the other says
‘white’. Now c’mon, I’m supposed to make a decision here?”
So where can judges turn for help in performing this new
gate keeping role? Traditionally, that kind of help in our adversarial system
has come from experts hired by parties to the litigation. Virtually every area of law practice uses
experts at some point. But for someone
genuinely interested in having the most valid and reliable science surface
during litigation, the reliance on parties’ experts poses several problems.
Attorneys for both sides only hire experts who will support
their position (although some times they will retain other experts just to keep
them from being hired by the opposing side).
They are interested in finding the “best witness,” not necessarily the
best scientists or engineers. This has led to the “hired gun”
phenomenon, where people who are willing to testify to marginal or even dubious
scientific positions are in great demand and command large fees.
The Federal Rules of Evidence state that the role of
the expert is to “assist the trier of fact to understand the evidence…”
However, in reality, the adversarial system fosters persuasion over
education. Lawyers consider science a
tool to further their client’s interests.
They will selectively present evidence according to their client’s
needs. As one criminal defense attorney
has publicly stated, “I may not want the jury to understand the science! It’s my duty to my client to create a
reasonable doubt.” In other words, good science might just get
in the way.
Following from two is that the adversarial system places
great emphasis on discrediting the expert, thereby diverting attention away
from the science. When you believe that
a judge or jury cannot distinguish between the technical presentations of
scientists from the opposing parties, your best legal strategy may be to attack
the credentials or alleged biases of the opposing expert.
And following from three is the unfortunate consequence that
the best scientists and engineers simply don’t want to have anything to do with
the legal system. They do not want to
be an expert for one side or the other, either because they don’t believe that
the best science will have a chance to surface or because they do not want to
expose themselves to the indignities of attacks on their credibility. This is
clearly an unsatisfactory situation for a system that increasingly relies on
experts as crucial to the administration of justice.
Many of the problems associated with using science and
technology in judicial proceedings can be traced to the clash of the two
cultures of law and science. Science is
not merely a body of knowledge; it is a process for proposing and refining
explanations about the world that are subject to further testing. Scientists value precision and accuracy, and
seek a high level of confidence in their findings, which may require an
extended period of time. The legal
system, however, operates with a different set of values and rules than
science. It seeks consensus on its
version of the truth, that is, pragmatic justice at a particular point in time
so that people can get on with their lives.
Scientific and technical information is viewed simply as a tool to
achieve that end. When scientists enter
the legal arena, they are subject to pressures and constraints imposed by the
legal system. As a practical matter,
their options are limited, and the expert is often caught between the
proverbial rock and a hard place.
Scientists and engineers are cautioned by their professional ethics not
to confuse partisanship with scientific rigor.
But it’s tough to be impartial in the adversary system,
where one side recruits you. There are
pressures from attorneys who want to make sure that you are on their client’s
side. There is a tendency to identify
with the side for which one is testifying.
And there are expectations associated with receiving a fee—the expert’s
expectations as well as those of the client.
Under such pressures, the norm of disinterestedness that is
associated with the search for truth in science may be trumped by the rules of
the legal system. Experts may find
themselves making statements that they would not be comfortable making in a
scientific forum. As one court
observed, “these witnesses say and conclude things which, in the Court’s view,
they would not dare report in a peer-reviewed format.”
In the extreme, this can lead to what is termed “litigation science,” or
evidence that is produced solely for litigation without any formal peer review.
There may be a way to avoid some of the pitfalls associated
with expert testimony—the use of experts appointed by federal judges to serve
the court rather than the parties to litigation. This is not a novel idea, having been proposed at least as far
back as 1886 in the American Law Review. Judges have the power to appoint such experts through several
sources, including the Federal Rules of Evidence cited earlier. Those rules state that “The Court may appoint any expert witness agreed upon by the
parties, and may appoint expert witnesses of its own selection.”
There are a number of advantages of court appointed
experts. They are not under pressure to
tailor their testimony according to partisan lines. They can put partisan testimony into perspective that enlightens rather than
confuses. They may be able to
neutralize any unfair advantage one side has over the other with more resources
to hire experts, creating a more even playing field. They can help to reduce costs and delays precipitated by battle
of the parties’ experts by encouraging settlement or by narrowing issues prior
to trial so that time is allocated to areas of real scientific controversy. And
they may increase the willingness of some of the best scientists and engineers
Despite these advantages, federal judges have rarely used
their authority to appoint experts.
1991 survey by the
Federal Judicial Center, the research and education arm of the Judicial Branch,
found that of 431 judges responding, only 20% (86) had appointed an expert, and
of those that did less than half had done so more than once. But it is worth pointing out that when
judges did appoint such experts, they overwhelmingly reported a high degree of
satisfaction. And 87% (375) of the
judges surveyed expressed the view that court appointed experts are likely to
be helpful in some cases.
The notion of court appointed experts is not without its
critics. It can be argued that no
scientist is truly neutral. If they are
expert, then they come to the issues with strong ideas about the science
involved, which might tip the balance in favor of one or the other
parties. Parties’ attorneys may be
reluctant to cross-examine vigorously the court appointed expert for fear of
alienating jurors. Court appointed
experts place an additional financial burden on the parties since they will
likely be saddled with paying the expert’s fees. And no attorney would be pleased with the prospect of
encountering a witness who is only accountable to the court.
Despite these criticisms, the primary reason given by judges
for not appointing experts is that they don’t know how to find one to meet
their immediate needs. The American
Association for the Advancement of Science (AAAS) has designed a project
intended to meet this need.
Appointed Scientific Experts (CASE)—A AAAS Demonstration Project
AAAS has launched a five-year pilot project to enhance the
availability of reliable scientific and technical expertise to the
judiciary. The project will initially
focus only on the federal district courts, in primarily civil cases with a
strong scientific or technical component.
It will be evaluated by the Federal Judicial Center, the research and
education arm of the Judicial Branch.
The project will be considered a success if it provides scientific and
technical experts in a way that federal judges find useful. Judges are, after all, our clients. On what basis would judges be likely to
consider the project useful?
Expert would be sufficiently independent to avoid either the
appearance or the actuality of bias for or against any party to the litigation.
Expert would enable juries or judges to understand the
evidence or to determine a fact or issue.
Expert would be provided in a timely manner, as defined by
Expert’s knowledge would be related to the factual and legal
issues of the case.
Expert would be deemed reliable in meeting the legal
standards of admissibility.
Expert would be affordable, given the resources available to
the litigants and the court.
The project was endorsed by Supreme Court Justice, Stephen
Breyer, who at the 1998 AAAS Annual Meeting, declared that AAAS has “offered
their help. We in the legal community
should accept that offer….The result, in my view, will further not only the
interests of truth but also those of justice.”
In addition, several federal judges were involved in developing the
project’s design, and a number are now serving on various project committees.
The project infrastructure includes a Project Advisory
Committee, which will provide guidance on the overall structure, objectives,
and direction of the demonstration project.
The committee will be active in the development of educational materials
and the guidelines for conflicts of interest, and will appoint members to subcommittees
on education, professional standards, and evaluation. The Advisory Committee will not be involved in the day-to-day
operation of the project. Specifically,
the committee will have no role in the selection of cases or in the
identification and recruitment of experts for these cases.
An Education Subcommittee will oversee efforts to develop
educational materials for experts selected by the courts. The materials will assist experts in
understanding aspects of the adversarial process, such as discovery and
cross-examination so that they can be prepared for their participation in the
legal process. Other educational
material will be prepared for judges to provide information about the
project. In addition to this general
material, judges inquiring about assistance in selecting an expert will be
given procedural materials, and judges who are appointing a CASE expert will be
provided with additional material that could be helpful in managing pretrial
and trial proceedings.
A Professional Standards Subcommittee will draft guidelines
for conflicts of interest, including questionnaires or other instruments
designed to gather pertinent information for use by the courts. In addition to considering questions
regarding conflicts prior to appointment, the subcommittee will also address
policies relating to permitted professional activities following an expert’s
appointment by the court.
An Evaluation Subcommittee will review the evaluation plans
prepared by the Federal Judicial Center and advise project staff and the
Advisory Committee on the evaluation process.
There will also be a Recruitment and Screening Panel,
appointed by staff, which consists of 27 individuals from key scientific and
engineering disciplines. These men and
women will be well known and respected and, in turn, be acquainted with a great
many people in their own field or related areas of research. The panel will have two main roles. The first will be to help identify
scientists, engineers or physicians who are highly qualified in the area of
expertise sought by a judge who has requested assistance from the project.
Because names of potential experts may come from sources
other than panel members – for example, from scientific societies – the panel’s
other important role will be to vet the recommended scientists, engineers or
physicians for scientific merit, reputation, and the ability to communicate
highly technical information to non-scientific audiences.
How The Project Will Work
A court must first contact the project for assistance. If the project accepts the case, staff will
determine type of expert(s) needed.
Three methods will be employed to identify experts: (1) online databases that have been vetted
by others; (2) science and engineering societies and education associations;
and (3) the recruitment and screening panel.
For every request, we hope to send the court two to four candidates, all
of whom will have to complete a “conflict of interest” questionnaire. While we believe we can eliminate from
consideration experts with obvious conflicts, it will be up to the court to
make final determination of whether a more subtle conflict is
We envision several possible rolls for experts we
provide. They could serve as trial
witnesses; help to educate judges and juries about the technical issues
involved; advise court in pre-trial (admissibility) proceedings, discovery, or
settlement phase; and/or assist in the damage or penalty assessment phase.
We believe the project can improve the way scientific and
technical information is handled by the courts. At the same time, the project will offer scientists and engineers
an opportunity to perform a valued public service. As a result, the integrity and image of both the judiciary and
science will be enhanced and, we hope, justice will be better served.