Tactics for Nailing the Defense Expert

Ira H. Leesfield
Leesfield Scolaro
2350 South Dixie Highway
Miami, FL 33130
Tel: (305) 854-4900
Fax: (305) 854-8266
E-mail: leesfield@leesfield.com

I. Introduction

Nailing the defense expert involves preparation, planning, and organization. The defense experts you will encounter have usually testified in many cases. They have given several depositions and are prepared for the usual tricks at trial. Sometimes, their testimony was less than stellar, and may be available to undercut their current testimony. Nailing them down on bias, inconsistencies, or plain logical errors can prove damaging to the defendant’s case. Sometimes, they are open to collateral attacks on their credentials. Most of the leg work that you will do before trial seeks out the expert’s vulnerability and plans to work these to your advantage.

When encountering the defense expert, a trial lawyer must proceed with humility. You will face a person who is usually operating within his or her focused area of expertise, and who has years of experience with giving testimony in this area. This does not mean the witness is unimpeachable or the intellectual superior to the lawyer, but it does mean that there will be little margin for error, and that the ill-prepared lawyer can do more harm than good in deposing and cross-examining this witness.

With this in mind, there is a lot that can be done to minimize the harmful effects of the defense expert’s testimony in your case. You can seek to limit the opinions to which the witness testifies, exclude the testimony altogether, or undercut the expert’s ethos in front of a jury. Therefore, preparation and execution of discovery, depositions, and cross-examination with respect to the defense expert should be part of the “tool kit” of an effective trial lawyer.

II. Preparing to Encounter the Expert WitnessA. Do Your Background Research on the Expert

When preparing to either depose the expert witness or cross-examine the witness at trial, there is a significant amount of preparatory work that should be done to ensure a favorable result. The best place to begin is by researching background information on the expert:

  • Consult the ATLA Exchange for background research that has already been performed by your colleagues, and which they have made available. The Exchange contains databases of legal and technical information on many regularly updated topics.

  • Other attorneys, locally or nationally, have most likely encountered this expert witness before. Do a jury verdict search to learn which colleagues have been up against the expert in the past, and call them. Networking in this way may produce helpful prior deposition or trial testimony from the expert, or tactics that have worked in the past when examining the witness.

  • Obtain the expert’s CV and independently research the organizations and professional affiliations listed. Make sure the witness is actually a member of these organizations, and what the organization actually does. If possible, get the witness’s application to the organization.

  • Check the expert’s license and credentials with the state’s regulatory authority.

  • Review and analyze the witness’s CV and other claims of expertise. For example, if the witness claims to have published several articles, find out whether these were peer reviewed, in what type of publications these appeared, and whether the publications are considered authoritative or marginal in the field.

  • Get a copy of all the books or articles which the expert has published, to get any opinions that the witness may have expressed which are helpful to your case or inconsistent with the anticipated testimony.

  • Perform a search of civil trial databases, such as those on LEXIS or WESTLAW, and identify where the expert’s testimony may have been discussed in later appellate opinions, either positively or negatively.

  • Contact court reporters in the area around where the expert regularly lives or works. They may be able to provide you with copies of the witness’s prior deposition or trial testimony.

B. Be Knowledgeable About the Subject Matter

It is essential that you know everything about the subject matter to which the defense expert will testify. For example, if the expert is testifying in a medical malpractice case, know the relevant medicine. In a products liability case, learn everything possible about the engineering of the product and any similar alternative products on the market.

An expert witness is well versed on the subject matter to which he or she is testifying. Therefore, use the experts that you yourself have retained as a starting point in your education. These witnesses can assist you in analyzing and understanding the technical or scientific aspects of the case well in advance of trial.

A second way to gain knowledge about the subject matter of the case is to consult authoritative books, learned treatises, and periodicals. While these may or may not be admissible on direct or cross-examination of any witness in the case, they are good sources for improving your own knowledge. Educating yourself in this way may be time consuming, but it will pay off when you depose or cross-examine the defense experts.

Knowledge of the subject matter is not just about learning the scientific or technical information; it also includes getting a firm grip on all the facts in the case. If a defense expert is not fully prepared with all the facts and circumstances at hand, you can effectively discredit this witness on cross-examination. If the basis for the expert’s opinion omits some crucial fact in the case, you may undermine the opinion altogether. Therefore, the best place to start becoming knowledgeable about the subject matter in the lawsuit is familiarizing yourself with all the facts in the case.

III. The DepositionA. Get Into a Rhythm

Eliciting some positive statements from the defense expert often depends on being able to get into a rhythm in the questions and answers. This involves taking the deponent through a line of questioning in a manner that is easy to follow but hard to contradict. You want to get the witness into the habit of agreeing with you during a line of questioning – or, changing tactics, to become comfortable disagreeing with you during the deposition.

When establishing a rhythm, begin with non-contentious questions with which the deponent cannot disagree. Begin with general premises or propositions and gradually work toward the more specific propositions that logically follow from what you have already established. In other words, if you can get the deponent to admit that fact "A" is true, you should be able to get him or her to admit fact "B" and from there to admit fact "C," or lose all credibility. Once you get the deponent to the final point, any answer given will help your case.

For example, in the context of a mild traumatic brain injury case with a negative CT scan following the trauma where the defense neurologist claims that your client sustained no brain damage might involve the following:

Q. The brain is gelatinous in composition, isn't it?
A. Yes, it certainly is.

Q. The brain sits in cerebrospinal fluid, isn't that right?
A. That's correct.

Q. And, it's encased by a person's skull, correct.
A. Yes.

Q. The inner surface of the front of a person's skull has irregular, sharp, bony protrusions, does it not.
A. It does.

Q. When a person suffers a traumatic blow to the back of the skull, the brain can be thrust against the sharp bony protrusions at the front of the skull, right?
A. That's true.

Q. This can cause what's known as a contrecoup injury to the brain, right?
A. Yes.

Q. That's where the brain is damaged on the opposite side from the primary traumatic injury to the skull, right?
A. Yes.

Q. When the brain is thrust against these sharp bones at the front of the skull, it can cause shearing and tearing of the neurons or nerve cells in the brain, correct.
A. Yes.

Q. This can cause what physicians call "traumatic brain injury" isn't that right?
A. Yes, that's true.

Q. Neurons are microscopic aren't they?
A. Yes.

Q. The shearing and tearing of each individual neuron, therefore, occurs on a microscopic level, doesn't it.
A. Yes, it does.

Q. In a case where someone has sustained mild traumatic brain injury, you would not expect there to be a large, concentrated area of damage to the brain, would you?
A. No, not necessarily.

Q. Unless there is a large concentrated area of damage, CT scans are not sensitive enough to view microscopic damage to neurons, correct?
A. That's accurate.

Q. So, someone can have actual damage to their brains that is not visible on a CT scan, isn't that true?
A. Yes, that's true.

Q. Therefore, my client's negative CT scan does not rule out damage to her brain, does it?
A. No, it doesn't.

Whether you need to be as detailed on a specific issue or, in fact, far more detailed than the example above, depends on the degree of resistance you get from the adverse expert. In short, when you establish a rhythm, you are playing on the deponent’s familiarity with a subject. Once they become accustomed to answering questions of general principles, you can slowly draw them into more specific or contentious areas your case, and force them into either answering in a way that is advantageous to your case, or face losing credibility with an answer that does not follow logically from the basic premises you have established.

B. Modify Your Style for Each Deposition

In most cases, defense counsel is sitting in with you every time you take a deposition. They will note your style, figure out how you go about eliciting favorable information, and learn when to make objections that interrupt your rhythm or train of thought. Because of this, it is a good idea to change your presentation with each deposition. If you take a long time to set up the background of the expert and possible areas of impeachment in one deposition, then get right to the point in the second. Each time, you should strive to make minor, yet salient, changes to your style, to keep the opposing counsel off balance.

C. Ask Questions the Witness is not Prepared to Answer

The defendant will prepare the expert for his or her deposition. However, that does not mean that the witness will be prepared on every point. Some experts are often not prepared as extensively to answer certain questions. For example, an accident reconstruction expert may not have knowledge about the biomechanics in the case, but may be able to concede certain favorable facts for your side. If you can figure out the focus of the witness’ preparation, you may catch him or her off-guard for other areas of inquiry.

The defense expert may not have reviewed all of the available information provided by the defense counsel. Therefore, it is important to question him with respect to exactly what he has reviewed in reaching the opinion he expresses, what facts he may have been given by defense counsel, and what discussions, if any, he has had with the defendant. Where you find that he or she has not reviewed certain materials, ask them hypothetical questions including this information. This may yield beneficial concessions that will contradict the expressed opinions if the favorable facts are ultimately established at trial.

D. Do Not Settle for Unanswered Questions

Typically, where a specific question is asked by the plaintiff's lawyer, a defendant’s expert will give either a short answer which is not responsive to the question, or will engage in a long response which, again, does not contain a full answer to the question. There is a tendency to accept the long answer as having responded to the question. However, the question should not be left until it is specifically answered, regardless of how long it takes and regardless of how many of the defendant’s lawyers complain that the question was already answered a number of times. Typical inconclusive or evasive answers include:

  • “We prepared him for surgery.” Question: “Who is ‘we’?”

  • “We did it the usual way.” Question: “What is the usual way?”

E. Checklist of Specific Areas of Questioning You Must Never Overlook

(1) Obtain a very detailed account of all opinions, and the bases for such opinions. Inquire as to all assumptions, information and other evidence relied upon in formulating the opinions.

(2) If the expert states that he or she wants or needs to do additional work, find out whether or not it is recommended in his own personal opinion that further work be done. Also, commit the other side to another deposition.

(3) Ask questions to attempt to create doubt in the expert’s mind as to the accuracy of his or her opinion.

(4) Make certain you understand why the expert feels certain facts in the case are more important than others in formulating his or her opinion.

(5) Question the witness about the financial arrangements in the case and all cases that he or she has performed for the defendant or defense attorney. Determine the number of times the expert has testified for defendants in lawsuits.

(6) Ask how many times the expert consulted with defense counsel and other defense experts about the case. How much time, total, has the witness spent on the case, and how exactly was this time spent.

(7) Go through the expert’s CV or, if none, the witness’ work experience and education, particularly as it pertains to his or her credentials to testify in your case.

(8) What si the expert’s experience with the science or technology involved in your particular case. Is the expert a specialist or a generalist. If a specialist, does he or she specialize in a particular field that is relevant to the present lawsuit.

(9) Go over all tests performed by the expert. Find out how each was planned, and what variables were taken into account when performing any tests. Ask who was present for the tests, and whether they were filmed or photographed.

(10) Discuss key interrogatory answers and materials produced by the defendant.

(11) Inquire as to whether the expert received all materials requested of the defendant. If not, why? Has the witness been to the scene? What was learned? What was he or she looking for? Has the expert examined the product? What examination was performed?

(12) Ask about all reports produced by the expert, including whether they were oral or written, when they were submitted to the defendant, and who has copies of the reports.

(13) Determine whether anyone assisted the expert in arriving at the opinions offered in the case.

(14) See if you can get the expert to agree with any of your expert’s opinions. Explore whether he or she has read your expert’s reports, and what are the criticisms of those reports.

(15) Determine what, exactly, the witness will testify to at trial. Ask whether he or she has a list of questions to be asked, and what subjects will be covered by other experts.

(16) Ask whether the expert assisted the defense attorney in preparing for other depositions in the case. If so, how?

VI. Excluding the Defense Expert’s Testimony

One of the most effective ways to “nail the defense expert” is to exclude that witness’s testimony altogether. In the federal court and states that follow its standard, this involves Rule 702 of the Federal Rules of Evidence, and the dual Daubert / Kumho standard relating to expert witness testimony. Most case law, articles and publications on excluding witnesses under Rule 702 focus on the exclusion of plaintiff witnesses. Often overlooked is its offensive use by the plaintiff to exclude the defendant’s expert witnesses.

A. The Daubert / Kumho Standard

To effectively use Rule 702 to exclude the defense expert, you must understand the landscape that has been created by the rule as well as the Daubert decision and its progeny. Daubert, Kumho, and the cases interpreting those decisions have set forth various nonexclusive guidelines for trial judges to apply when determining the reliability of expert testimony. The following are a list of some of the more often-cited criteria:1

(1) whether the expert’s field is a “well-accepted body of learning” with reasonably well-defined standards;

(2) whether the expert’s theory or technique can be or has been tested;

(3) whether the theory or technique has been subjected to peer review and publication;

(4) the known or potential error rate of the theory or technique;

(5) general acceptance of the theory or technique within a relevant scientific community;

(6) the non-judicial uses made of the theory or technique;

(7) the extent to which the theory or technique relies upon the subjective interpretation of the expert; and

(8) the expert’s credibility to the extent that it affects reliability.

B. Using Daubert / Kumho Offensively

The key to excluding the defendant’s expert is using Daubert and its progeny to your advantage. First and foremost, the trial courts have been charged with the role of gatekeeping. Rule 702 and Daubert / Kumho force the court to make a preliminary assessment as to the reliability of the expert testimony. The Supreme Court called on trial courts and litigants to resolve the issue of expert witness qualifications “at the outset” of litigation.2 Various circuits have stated that although the trial courts have an independent responsibility under Daubert and Kumho to make a preliminary assessment of the expert’s reliability, unless the testimony is so inherently and obviously unreliable that it would be improper for the court to allow its admission.3

If you believe that the defense expert is subject to a Daubert / Kumho attack, the court will determine whether to hold a full evidentiary hearing on your motion to exclude the witness, or whether to make its determination of admissibility based solely on the arguments and materials presented to the court. This determination is within the discretion of the trial judge. In order to increase your chances of obtaining a hearing, however, the following areas should be covered in your motion:

(1) Attack the lack of methodology: An expert’s opinions must not be conclusory. An opinion that is conclusory or fails to set forth the underlying rationale is inadequate. “When an expert opinion is not supported by sufficient facts to validate it in the eyes of the law . . . it cannot support a jury’s verdict.”4 A jury verdict cannot rest solely on the expert’s “bottom line” conclusion, without some underlying facts and reasons, or a logical inferential process to support it.5

(2) Demonstrate the unreliability of the expert’s methodology: For instance, if the expert’s testimony has been disqualified in prior cases, bring this to the judge’s attention. Similarly, if other experts in the same field are regularly disqualified from cases, state the reasons for disqualification and show that this particular expert has similar deficiencies.

(3) Use depositions to point out defects in the expert’s testimony: Illustrating deficient theories or foundations for the expert’s opinion through prior deposition testimony is usually compelling to a trial judge. You should use the deposition to build a record of any gaps in the expert’s qualifications, foundations, methodologies, or reasoning.

C. The Daubert / Kumho Deposition

When you suspect that the defense expert may be subject to disqualification, the deposition should be used to build a record of any gaps in the expert’s qualifications, foundations, methodologies or reasoning. There are many subjects that may be covered in the deposition to set up the expert for disqualification:

(1) a precise explanation of each step in the expert's reasoning, methodology, or application of principles leading up to each conclusion;

(2) the factual bases and assumptions used by the expert, and the sources of these bases and assumptions;

(3) other fact sources which were available but not used (especially when expert relies on facts from the defendant);

(4) the standards, principles, or reasoning that allow the expert to rely on the defendant for important assumptions;

(5) whether the expert’s method or reasoning consists of a testable hypothesis, and, if so, whether it has in fact been tested;

(6) what tests were performed on the hypothesis, whether these can be reproduced, and whether there are other test protocols that have been used or described in professional literature to test this hypothesis or similar hypotheses;

(7) whether the expert knows if authoritative texts or periodicals are published in the expert's field, and which of these publications support the expert’s work in the present case;

(8) whether the expert's work in the present case has been or is subject to peer review;

(9) what professional standards apply to the expert’s field, and how those standards apply to the expert’s work;

(10) how does the expert explain any departure from these standards;

(11) whether expert's method, reasoning, and application of principles are generally accepted and why;

(12) the relationship of the expert’s technique to the methods which have been established as reliable in this particular field;

(13) how is the expert qualified to meet the accepted standards or methodology of the field;

(14) are there any non‑judicial uses to which the method has been put, and whether the expert’s testimony is based on legitimate, preexisting research unrelated to the litigation; or

(15) what are the objective sources for each step in the expert’s methodology and each factual assumption made by the expert.

V. Cross Examination

Before trial, you should have already deposed the defense expert, and performed background research on the witness. You will already know what testimony to expect from the expert, and how best to cross-examine based on that expected testimony. There may be one of several very helpful points that you can establish during the cross-examination, including:

(1) the witness is committed to a position that is contrary to common sense;

(2) the witness is biased against the plaintiff, or toward the defendant;

(3) the expert has an insufficient amount of information on which to base the opinion;

(4) the witness is testifying in a manner contrary to his deposition or report;

(5) the witness is intellectually dishonest (i.e. arbitrary, pompous, unyielding on the points to which he should yield, etc.); or

(6) the witness is not knowledgeable.

Effective cross-examination of a witness can negatively affect that witness’s credibility and lead the jury to mistrust it. By discrediting the witness, the defense will have a more difficult time in disproving the strength of the plaintiff’s claim. In other words, discrediting the expert will take the wind out of the defendant’s sails.

When pursuing a compelling cross-examination, it is always helpful to keep in mind the following list of tips compiled by professor Irving Younger:

The Ten Commandments of Cross-Examination
  1. BE BRIEF
    Keep your cross-examination short and succinct. Never make more than three points about a witness’s credibility.

  2. SHORT QUESTIONS, PLAIN WORDS
    Do not use legal words and phrases. Use plain English.

  3. NEVER ASK ANYTHING BUT A LEADING QUESTION
    A leading question puts words in a witness’s mouth by suggesting the desired answer.

  4. ONLY ASK QUESTIONS TO WHICH YOU ALREADY KNOW THE ANSWER
    If you do not know – or have a good idea of – the answer, do not ask the question.

  5. LISTEN TO THE ANSWER
    Listen carefully to the answers given by the expert so that you do not miss the favorable answer that contradicts the rest of the testimony in the case.

  6. DO NOT QUARREL WITH THE WITNESS
    Do not argue about an answer. It diminishes your ethos with the jury.

  7. DO NOT PERMIT THE WITNESS TO SIMPLY REPEAT ON CROSS WHAT THE WITNESS SAID ON DIRECT
    If you allow the witness to repeat large portions of earlier testimony, the only thing you accomplish is reinforcing that testimony in the jurors’ minds.

  8. NEVER PERMIT THE WITNESS TO EXPLAIN ANYTHING
    The use of only leading questions controls the witness’s attempts to explain the answers given.

  9. AVOID ONE QUESTION TOO MANY
    Know when you have obtained everything that is possibly helpful from a witness, then stop the cross-examination.

  10. SAVE IT FOR SUMMATION
    It is best to leave the jury in a state of unsatisfied curiosity. Nothing will make a juror more attentive than curiosity.

A. Planning and Organizing Your Questions

When planning and organizing your questions, merely knowing the subject matter or having good points for cross-examination is insufficient. It is essential to plan out the order of your subjects on cross and the order of questions within each subject. You should write out and have handy all the literature on the subject and prior testimony of the witness, with line and page number references to areas where you intend to impeach. To prevent the expert from displaying his or her knowledge, you should frame your questions so that you introduce and define the medical terms. For example, you may ask, “Doctor, there is a reference in the record to ‘necrosis.’ Necrosis simply means the death of tissue, does it not?”

B. The Order of Your Questions

No matter how qualified the expert may be, there is almost always something in his or her background and qualifications that you can initially raise in cross-examination to put doubt in the jurors’ minds as to the witness’s credibility. Following this initial inquiry, it is advisable to question the expert on subjects that you reasonably assume he or she will agree with.

This accomplishes two goals: it bolsters your own case while at the same time sets the stage for impeaching the witness. Delay making a direct attack on the expert until you have chipped away at his or her credibility to the point that the jury is now ready for direct confrontation. When the expert refuses to agree to crucial elements of your case, you then can use the collateral attacks to attack the witness’s bias, and the real reason the expert refuses to agree: he or she is a professional witness who is being paid to testify.

Do not go beyond the few issues you have selected to attack the expert’s credibility. Try to build up to a climax by ending on a strong point and stopping there, even if it is earlier than you had planned. You can always save some points for summation.

C. Maintain Control of the Witness

Maintaining control of expert witnesses can be difficult because defense experts are usually adept at speaking in public about their particular field of expertise, and are also experienced at testifying in court. It is particularly important to refrain from asking questions that require an explanation. Although difficult, frame your questions so that they require only a “yes” or “no” answer. Avoid open-ended questions, for which an experienced expert will jump at the opportunity to give a long pro-defendant narrative. Using well-crafted leading questions gives the cross-examiner the necessary control to direct the expert witness to the weaknesses in the defendant’s case and the strengths of the plaintiff’s case.

D. Areas of Impeaching the Credibility of the Witness

1. Qualifications

The expert’s qualifications – or lack thereof – are important to the jury’s evaluation of the weight to be given the testimony. An expert’s education, failure to obtain professional certification, or lack of personal experience with the technology or medicine at issue in the case are all areas that can discredit the expert in the minds of the jurors. Even if the expert is qualified in a particular area of expertise, if they have not been actively employed for a number of years, this can also be emphasized to the jury to show that he or she is a professional expert witness and unfamiliar with relevant advances in the science of the particular field.

2. Collateral Attacks

This attack generally involves portraying the expert as a professional witness. If the expert testifies frequently, or derives a substantial portion of his or her income from reviewing legal matters and testifying in court, this can be developed through cross-examination to show bias. The point that you want to make is that the expert is not being objective, but is rather testifying to increase his or her income. Often, the expert is extremely qualified in one area but is testifying outside this core specialty. The reason for “straying” should be pursued.

The mere fact that the expert is being paid is not enough to raise a doubt in jurors’ minds as to bias. Jurors know that these people get paid to testify. However, if you fail to inquire of the defense expert as to whether he or she is being paid for their testimony, the opposing counsel will undoubtedly make a great deal out of the fact that your experts are being compensated. By not pursuing this line of questioning with the expert witness, you have missed the opportunity to neutralize the issue.

3. Prior Inconsistent Statements or Positions

A prior inconsistent statement or position is the most devastating testimony that you can elicit from the defense expert. Before using the inconsistency, it is necessary to first get the expert to firmly commit to his or her inconsistent in-court opinion or statement. You must then clearly identify the impeaching statement or testimony, so that the jury can make a comparison to what was stated in court. If you do not get the expert to firmly commit to the in-court statement, defense counsel may be able to adequately re-direct the expert to explain away the apparent inconsistency.

Prior inconsistent statements require a great deal of up-front research on the expert witness. These statements may be found in prior depositions or trial testimony, articles or books written by the witness, or even deposition testimony given earlier in the case. In identifying the impeaching statement, let the jury know where the statement was made, and under what circumstances. However, in doing so, never give the witness a chance to explain away the inconsistency.

4. Lack of Familiarity With the Facts

If the expert witness is not fully prepared with all the facts and circumstances surrounding the case, this may be used to discredit the testimony. For every opinion concerning an issue in the case, explore whether the opinion is based on all relevant evidence. Even if the witness testifies that the facts or information now called to his or her attention would not have impacted the opinion, merely suggesting that the opinion was based on an insufficient survey of the facts in the case will somewhat diminish the authority that the jury is likely to give the expert.

Related to insufficient knowledge of the facts, you want to explore whether these facts support the opinion that the expert is giving in the case. Many cases involve sharp distinctions of the facts given by the plaintiff and those advanced by the defense. In asking hypothetical questions, the expert should be presented with your view of the facts, and whether those facts would change his or her opinions. Many times, if the defense expert has only been presented with the defendant’s version of the facts, he or she will honestly answer that assuming your version of the facts would change the opinions that he or she holds.

It is important to emphasize to the jury that the expert’s testimony is merely an opinion, based on an assumed basis of fact. You must weaken the effect of the expert’s strong direct testimony by pointing out that the expert would have drawn different conclusions had he or she relied on different facts: facts the expert either did not know, or chose to ignore.

E. Obtaining Favorable Testimony

Any benefits that the defense may gain from the expert witness can be significantly minimized by securing favorable admissions or concessions during cross-examination. Cross-examination of the expert witness presents a unique opportunity to argue a case through this witness. You should try to obtain factual testimony or admissions from the defense expert that either support your theory or reinforces some position that you hold. It is also a good opportunity to gain factual concessions that may be used to contradict the testimony of the other defense experts.

It is very helpful to elicit facts or opinions from the defense expert about which your experts have already testified. Get the witness to concede that your experts’ opinions were not so contradictory as to be invalid, but rather that the defense experts only vary with respect to facts assumed when developing the opinions. Such concessions are usually achieved where you have a firm grasp of the underlying scientific or technical theories utilized by the expert, as well as a commanding knowledge of all the facts in the case.

1 Robert M. Whitney, A Practicing Lawyer’s Guide to the Application of Daubert and Kumho, 23 Am. J. Trial Advoc. 241 (Fall 1999).

2 Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 589 (1993):

Faced with the proffer of expert scientific testimony the trial judge must determine at the outset, pursuant to Rule 104(a), whether the expert is proposing to testify to (1) scientific knowledge that (2) will assist the trier of fact to understand or determine a fact in issue. This entails a preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid and of whether that reasoning or methodology can properly be applied to the facts in issue.

3 Waitek v. Dalkon Shield Claimants Trust, 934 F. Supp. 1068 (N.D. Iowa 1996); Hoult v. Hoult, 57 F.3d 1 (1st Cir. 1995).

4 Brooke Group, Ltd. v. Brown & Williamson Tobacco Corp., 509 U.S. 209, 242 (1993).

5 Sullivan v. NFL, 34 F.3d 1091, 1105 (1st Cir. 1994).