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Resolving Daubert Challenges

Motions to Strike, and Hearings Thereon

    To litigants filing certain types of pretrial motions, the Federal Rules of Civil Procedure offer lavish procedural guidance.  Would you like to file a motion for summary judgment?  No problem.  Rule 56 will walk you through it, telling you explicitly:

bulletwhen the motion may and may not be filed;
bulletwhether it may be filed by a cross-claim, counterclaim, or third-party defendant;
bulletwhether it may be filed in a declaratory judgment action;
bulletwhen a responsive brief is due;
bulletwhen evidentiary material offered in support or opposition must be served;
bulletwhat specific types of evidentiary material may be used;
bulletwhat any affidavits, in particular, must contain;
bulletwhat to do if affidavits are unavailable;
bulletwhat will happen if affidavits are tendered in bad faith;
bulletunder what substantive standards the court will review the motion;
bulletwhat kind of order the court will enter if the motion is only partially successful; and
bulletwhat the consequences for trial will be in the latter circumstance.

    By contrast, the rule devoted to motions to exclude evidence -- well, there is no rule devoted to such motions.

What the Rules Do Say

    There are rules devoted to motions in general, and some procedural guidance can be pieced together from those.  From Fed. R. Civ. P. 7(b)(1), we learn that motions, if not made ex parte or during a hearing or trial, must:

bulletbe in writing;
bulletstate with particularity the grounds therefor; and
bulletset forth the relief or order sought.

    Rule 7 also informs us that motions must follow the general rules of form applicable to pleadings, and that all motions must be "signed in accordance with Rule 11."  And from Fed. R. Civ. P. 6(d), we learn that motions must be served on all parties at least five days before the time set for hearing, that any supporting affidavits must be served "with" the motion, and that opposing affidavits may be served not later than one day before the hearing.  (These timetables may be adjusted, of course, by judicial order or local rule.)

    The Federal Rules of Evidence are also instructive.  Evidentiary objections are covered in Fed. R. Evid. 103, which tells us that "[e]rror may not be predicated" upon rulings admitting evidence unless "a timely objection or motion to strike appears of record, stating the specific ground of objection."  The Advisory Committee Notes to Rule 103 say that the reasons for requiring the objecting party to state the grounds for objection include "enabl[ing] opposing counsel to take proper corrective measures."

What the Rules Do Say, Restated

    Applied to pretrial evidentiary motions, the rules just discussed provide at least some procedural guidance.  A written motion challenging expert evidence under Daubert should be presented in the form of a motion to strike, together with any affidavits (and, by implication, any analogous supporting material) on which the movant intends to rely.  It should identify the specific testimony challenged, state the basis for objection with sufficient particularity to permit a response, and set forth all relief sought (or sought in the alternative).

    In other words, the motion should lay the cards on the table, as notions of due process would suggest even in the absence of specific procedural rules.  This principle is violated when the moving party:

bulletdoes not clearly identify the specific portions of the testimony to which the objections pertain;
bulletdoes not state the grounds for objection in sufficient detail to permit a response;
bulletholds evidentiary material on which the movant will rely (e.g., expert affidavits) for use on reply.

    Informed self-interest should inspire litigants to professionalism in their motions in limine, even if solicitude for their opponents' due process rights does not.  Not only will specificity and forthrightness preserve the record for appeal; they will also enhance the legibility and credibility of the motion.

    But if the movant does sandbag the proponent, protest should be made, and heeded.

What the Rules Definitely Do Not Say

    No rule requires that Daubert challenges be raised or resolved via pretrial motion, nor does any rule bar the district courts from reserving decision on Daubert objections until trial.  There may often be sound practical arguments for waiting.  Compare United States v. Nichols, 169 F.3d 1255, 1262-64 (10th Cir.) (no abuse of discretion in reservation of Daubert rulings until trial), cert. denied, 528 U.S. 934 (1999), with Dodge v. Cotter Corp., 328 F.3d 1212 (10th Cir.) (rulings at trial too cursory to permit appellate review), cert. denied, 540 U.S. 1003 (2003).  Caveat: Holding Daubert objections for trial may waive them in the First Circuit.  See Feliciano-Hill v. Principi, No. 04-1072 (1st Cir. Feb. 22, 2006).

Discovery on Motions to Strike

    Discovery may sometimes be necessary in connection with Daubert motions.  In particular, if either party relies on third-party affidavits in connection with the motion, an opportunity to depose the affiants should normally be afforded.

Responding to Motions to Strike

    Counsel obviously will file briefs in opposition to Daubert motions, and will often also file affidavits in support of the expert's testimony.  But another potential avenue of response, frequently overlooked, is to amend the challenged testimony.  That may not be feasible, of course, if the opposition's attack goes to the heart of the expert's approach or opinion.  Often, however, the testimony can be adjusted to accommodate or deflate the attack.  If the change does not eviscerate the proponent's case, it may be simpler to make such adjustments than to defend the expert's original articulation of his or her testimony.  A "change" in the testimony, for these purposes, may be only a simple clarification or elaboration, but sometimes there is no harm in going so far as to concede a valid point (especially if the point is not very material).  It needs to be remembered that the expert's report is not a final exam, where the answers can never be adjusted once handed in.

Hearings on Motions to Strike

    The moving party often wants a Daubert hearing.  There are several obvious reasons why live hearings may work to the movant's tactical advantage:

bulletthey are a potential vehicle for what litigators call "educating the court";
bulletthey provide a free shot at additional cross-examination;
bulletthey increase the nonmoving party's (and perhaps the expert's) burden and expense; and
bulletthey bestow on the motion a greater sense of occasion.

    Language can be found in some early appellate decisions suggesting that live hearings are mandatory when Daubert objections have been raised.  It is believed, however, that in no circuit is any such rule now thought to prevail.  In Kumho Tire, the Supreme Court made it plain, albeit in dictum, that district courts, in their sound discretion, may convene live hearings or not, depending in part on the relative novelty or complexity of the issues.  In any event, Fed. R. Civ. P. 43(e) clarifies that district courts may "hear" motions on affidavits, without live testimony.

    A "paper" hearing may be especially suitable when Daubert motions involve complex scientific testimony.  Orderly exposition is at a premium in such contexts, and courts may also benefit from being able to review difficult scientific material in written form at their leisure.  But if no live hearing is convened, oral argument becomes doubly desirable, because it supplies the only vehicle whereby the parties and the court may engage in the sort of give-and-take that inquiry into the validity of expert opinion commonly requires.


    The objecting party will usually remind the court that the burden falls on the proponent of evidence to establish its admissibility.  It is useful, in this context, to distinguish burdens of production from burdens of persuasion.

    To meet his or her burden of production, the proponent must offer evidence -- or other material, see Fed. R. Evid. 104(a) -- sufficient to make out a prima facie case of admissibility.  In the case of experts, this showing usually may be made, in whole or in part, through testimony from the experts themselves.  If appropriate care has been taken in preparation of the expert's report, it may well contain everything required for this purpose.  Usually, at least, the report will recite the expert's qualifications, explain and defend the methodological steps taken by the expert, and state how those steps support the expert's opinion.

    With that, the proponent's burden of production should be at an end.  It should remain only for the proponent to carry the burden of persuasion.  This implies that the proponent is not required to offer evidence or other material to rebut every methodological criticism that the adversary may raise.  Obviously counsel will wish to rebut whatever attacks they can, as forcefully as possible, if only because the burden of persuasion still matters.  But no one should suppose, for example, that an objecting party is entitled to exclusion as a matter of law merely because the proponent has failed to submit affidavits or similar material in response to objecting counsel's every point.

    By the same token, proponent's counsel should not seek refuge in the mere prima facie admissibility of their expert's opinion.  Prima facie admissibility is seldom the ultimate question.  Trial courts will recognize the risk of reversal if they admit testimony without a plausible response to a well-supported and facially legitimate reliability challenge.  The safest course is to do everything possible to help the expert survive the most exacting scrutiny -- protesting, all the while, that undue perfectionism is at loggerheads with the liberal standards for admissibility under modern evidentiary jurisprudence.

Preserving Error

    Fed. R. Evid. 103(a) says that if the trial court makes a "definitive" ruling on a pretrial evidentiary motion, error is preserved with no need for the parties to make formal offers of proof, or renew their objections, at trial.  But what is a "definitive" ruling?  It will save heartache to assume the worst, and make the offer of proof, or renew the objection, at time of trial.  Certainly it can't hurt.  Judges have been known to change their minds.


Rule 16
The Report
Special Masters
Motions in Limine
Rule 56
Model Local Rule