Expert Witnesses and Motions in Limine

Brian D. Chase (Bisnar Chase Personal Injury Attorneys) and Scott D. Raphael (Litigitechnology, Inc.)

Introduction

Since well prior to the 1986 Discovery Act, parties were at best committed to guesswork in ascertaining what expert discovery would be permitted at trial based on pretrial inadequacies in the disclosure of expert witnesses, of the scope of expert witnesses’ opinions, the transactional nature and source of acquisition of the expert’s opinions, and the adequacy of the expert’s deposition testimony as to the scope of his anticipated trial testimony. This followed largely from the lack of any meaningful guidance by the Courts or the Legislature on these subjects.

The cost of this uncertainty was not insignificant, with many practitioners discovering only for the first time on a motion in limine at trial that their entire pretrial case strategy would be entirely altered or severely compromised by the wholesale exclusion (or admission) of all or part of both proper and improper expert testimony.

This state of relative confusion has been largely ameliorated by a string of important and informative recent Supreme Court opinions greatly clarifying the permissible boundaries of expert testimony at trial based on the adequacy of the parties’ compliance with their pretrial disclosure obligations. Even so, significant areas of misunderstanding about the permissible scope of expert witness trial testimony, e.g., what limits exist on bootstrapping hearsay, remain problematic even when experts have been properly designated and have given meaningful depositions.

This article explores the appropriate role of the motion in limine as a tool of stability and predictability in ensuring the integrity of pretrial strategy vis-a-vis anticipated expert witness testimony, as well as some useful pointers on use of in limine motions prophylactically to curb potential evidentiary abuses at trial by the adversary, i.e., the very purpose for the in limine motion.

Overview of the Limine Motion

In Kelly v. New West Federal Savings (1996) 49 Cal.App.4th 659, the Second District Court of Appeal provided what is probably the first useful discussion in length concerning the genesis and purpose of a proper in limine motion.

Motions in limine are a commonly used tool of trial advocacy and management in both criminal and civil cases. Such motions are generally brought at the beginning of trial, although they may also be brought during trial when evidentiary issues are anticipated by the parties. In either event, they are argued by the parties, either orally or in writing or both, and ruled upon by the trial judge. The usual purpose of motions in limine is to preclude the presentation of evidence deemed inadmissible and prejudicial by the moving party.

A typical order in limine excludes the challenged evidence and directs counsel, parties, and witnesses not to refer to the excluded matters during trial. (3 Witkin, Cal. Evidence, supra, §2011 at p. 1969.) “The advantage of such motions is to avoid the obviously futile attempt to ‘unring the bell’ in the event a motion to strike is granted in the proceedings before the jury.” (Hyatt v. Sierra Boat Co. (1978) 79 Cal.App.3d 325, 337, [145 Cal.Rptr. 47].) [¶] Motions in limine serve other purposes as well. They permit more careful consideration of evidentiary issues than would take place in the heat of battle during trial. They minimize side-bar conferences and disruptions during trial, allowing for an uninterrupted flow of evidence. Finally, by resolving potentially critical issues at the outset, they enhance the efficiency of trials and promote settlements. [Citation.]” (People v. Morris (1991) 53 Cal.3d 152, 188, 279 Cal.Rptr. 720, 807 P.2d 949, disapproved on an unrelated ground in People v. Stansbury (1995) 9 Cal.4th 824, 830, 38 Cal.Rptr.2d 394, 889 P.2d 588.) (Id., 49 Cal.App.4th at 669-670. )

Kelly is worthwhile reading, as the Court explains in useful detail the distinctions between proper and improper in limine motions in a modern litigation world where, as the Court observes, it is not uncommon for defense firms to file scores of motions in limine many of which comprise an inappropriate use of the device. (Kelly, supra, 49 Cal.App.4th at 669.)

Chiefly, motions seeking prophylactically to exclude obviously improper or irrelevant or highly prejudicial evidence remain the primary objective behind and utility of the motion. This includes defining the boundaries of permissible expert trial testimony in light of the proscriptions of C.C.P. § 2034(j), which mandates the exclusion of expert testimony after timely compliance with the exchange provisions of § 2034(f), for a variety of reasons. These include the unreasonable failure to: (1) List the witness as an expert under subdivision (f); (2) Submit an expert witness declaration; (3) Produce reports and writings of the expert witness under subdivision (g); and (4) make the expert available for deposition under subdivision (i).

In addition to the foregoing, recent appellate decisional authority has also now clarified and authorized the exclusion of certain expert testimony at trial: (1) which exceeds the scope of the descriptive designation in the expert declaration of the anticipated areas of the experts’ trial testimony (Bonds v. Roy (1999) 20 Cal.4th 140), and (2) which exceeds the scope of the expert’s representations at deposition as to the anticipated areas of the experts’ trial testimony (Jones v. Moore (2000) 80 Cal.App.4th 557). Also properly excluded by the in limine motion are illegal attempted substitutions of experts via the “supplemental” designation procedure of C.C.P. § 2034(h). (See, Basham v. Babcock (1996) 44 Cal.App.4th 1717)

Another area of expert witness disclosures and scope of trial testimony fraught with uncertainty and peril revolved around the handling of the “non-retained” expert. From Hurtado v. Western Medical Center (1990) 222 Cal.App.3d 1198, 272 Cal.Rptr. 324 and Huntley v. Foster (1995) 35 Cal.App.4th 753, 41 Cal.Rptr.2d 358, the Courts of Appeal seemed to make it clear that a treating physician as a percipient expert was not a “retained” expert as to whom an expert witness declaration under § 2034(f)(2) was required. Then, in Plunkett v. Spaulding (1994) 52 Cal.App.4th 115, 60 Cal.Rptr.2d 377, the Third District Court of Appeal held that this was fine unless the treater had also formed an opinion on the standard of care employed by a prior treating physician, in which case the treater now had to be “retained” in order to express such opinions, regardless of whether those opinions were percipient ones formed during the course and scope of the patient’s treatment. Plunklett created substantial confusion and lack of future guidance because it looked to the qualitative nature of the opinions themselves on a case-by-case basis as determinative, rather than focus on the time and place when the opinions had been formed (i.e., genuinely “percipient” expert opinion formation), as the statute seemed to indicate.

Fortunately, it its recent decision in Schreiber v. Estate of Kiser (2000) 22 Cal.4th 31, 91 Cal.Rptr.2d 293, the Supreme Court finally cleared up years of judicial confusion over the critical distinction between “retained” and “non-retained” experts, holding that a non-retained, percipient expert could express any opinions formed during the course of his or her treatment, including standard of care opinions. The Court’s opinion appears to embrace within the “non–retained” classification, any expert whose opinion is formed ordinarily during the transactional course of his or her ordinary work, such as coroners, fire investigators, investigating police officers and public accident investigators. That decision facilitates additional motions in limine which should not be overlooked, and which are discussed below.

Based on the current state of the law, the following are a checklist of motions in limine which should be considered as part of every practitioner’s pretrial strategy. Keep in mind that all in limine motions directed at expert testimony vulnerable under C.C.P. § 2034(j) depend upon the assumption that there has been a prior timely expert witness exchange between the parties.

Motion to Exclude Undesignated (Including) Nonretained Experts, and Insufficiently Identified Nonretained Experts

The most obvious of the expert witness motions in limine is to exclude expert witnesses who have never been designated. Failure to designate a witness as an expert in the designation required by C.C.P. § 2034, who will offer expert testimony at trial, requires exclusion of that witness properly facilitated through an in limine motion. C.C.P. § 2034(j)(1). See, Province v. Center for Women’s Health & Family Birth (1993) 20 Cal.App.4th 1673, 1681-1684, 25 Cal.Rptr.2d 667 [non-retained, percipient witness not listed as an expert improperly permitted to testify as to expert medical opinion], disapproved on other grounds in Heller v. Norcal Mutual Ins. Co. (1994) 8 Cal.4th 30, 41 32 Cal.Rptr.2d 200, Richaud v. Jennings (1993) 16 Cal.App.4th 81, 90-91, 19 Cal.Rptr.2d 790 [party desiring to call an expert not designated when expert witness information was exchanged must move to augment its expert witness list under subdivision (k) ]; Zellerino v. Brown (1991) 235 Cal.App.3d 1097, 1117-1118, 1 Cal.Rptr.2d 222 [plaintiff’s conduct “prejudiced the defense, which did not have the ability to counter the testimony of the belatedly disclosed experts”].) The only exception to this rule is rebuttal expert testimony, discussed below, which is rarely permitted as a practical matter and is very narrowly construed.

This includes both “retained” experts, and “non-retained” experts such as treating physicians, police officers, coroners, etc. It is expressly statutorily authorized by C.C.P. § 2034(j)(1), and by the Second District Court of Appeal’s February 7, 2002 decision in Kalaba v. Gray ___ Cal.App.4th ___, 2002 D.J.D.A.R. 1577. As Kalaba noted, “…treating physicians are not ‘retained experts’ within the meaning of section 2034, and no expert declaration is required when a party intends to call a treating physician for the purpose of eliciting expert testimony; it is sufficient if a treating physician is identified by name and address in the proponent’s designation of expert witnesses. Where, as here, the treating physicians are not listed or identified by name but simply referred to in the designation as ‘all past or present examining and/or treating physicians,’ there has been no compliance with the letter or the spirit of section 2034, and the trial court acts within its discretion when it excludes expert testimony by non-designated doctors.” Id., ___ Cal.App.4th at ___, 2002 D.J.D.A.R. at 1579. Kalaba further makes clear that an insufficient designation of a non-retained expert (failure to provide both name and address of the non-retained expert) are equally grounds for exclusion of a non-retained expert under C.C.P. § 2034(j)(1).

Schreiber and Kalaba would not appear limited in scope of application solely to non-retained experts who are treating physicians. In the advent of Schreiber, it is settled that non-retained “percipient” experts are experts who are required to be designated under C.C.P. § 2034(f)(1)(A) because their opinion testimony is “related to a subject that is sufficiently beyond common experience that the opinion of an expert would assist the trier of fact…” as defined under Evid.C. § 801. (Schrieber, supra, 22 Cal.4th at 34.) Schreiber held that an expert declaration is not required for such “percipient” experts, such as treating physicians, “and [s]he may testify as to any opinions formed on the basis of facts independently acquired and informed by his [or her] training, skill and experience…includ[ing] opinions regarding causation and standard of care because such issues are inherently in a physician’s work.” (Schreiber, supra, 22 Cal.4th at 39.) Similarly, “non-retained” or so-called “percipient” experts logically embrace governmental accident investigators, coroners, and even “[h]ighway patrol officers, garage men, automobile mechanics and others with special experience [who] may testify on various matters in issue in automobile accident cases.” See, Visueta v. General Motors Corp. (1991) 234 Cal.App.3d 1609, 1616. The common thread is that each may have acquired information and developed an expert opinion as part of his or her common job duties, but not necessarily in anticipation and/or for the purposes of later testimony in litigation.

But regardless of whether they are “retained” for the purposes of expressing an opinion at trial, or are “non-retained” in that they may have formed percipient opinions independently during the course of their professional duties, failure to include them in the designation, and in the case of non-retained experts, by at least name and address, mandates exclusion under C.C.P. § 2034(j) which may be achieved through a motion in limine. Kalaba, supra.

Motion to Exclude Areas of Testimony Not Set Forth in Expert Declaration

The next most basic of expert in limine motions excludes areas of retained expert opinion not described in the “substance” of the expert witnesses’ anticipated testimony portion of the declaration required by C.C.P. § 2034(f)(2)(B). Prior to Bonds v. Roy, supra, the Courts of Appeal permitted parties’ experts to testify at trial broadly, frequently beyond the subject matter areas set forth in the expert witness declarations, regardless of their incompleteness and/or inaccuracies. See, e.g., Casteneda v. Bornstein (1995) 36 Cal.App.4th 1818, 43 Cal.Rptr.2d 10, Martinez v. City of Poway (1993) 12 Cal.App.4th 425 15 Cal.Rptr.2d 664. In Bonds, supra, the Supreme Court overruled these prior decisions, pointing out that:

[w]hen an expert is permitted to testify at trial on a wholly undisclosed subject area, opposing parties similarly lack a fair opportunity to prepare for cross-examination or rebuttal. It makes little practical difference whether the party proffering the expert testimony failed to submit an expert witness declaration or submitted an inaccurate one….In short, the statutory scheme as a whole envisions timely disclosure of the general substance of an expert’s expected testimony so that the parties may properly prepare for trial. Allowing new and unexpected testimony for the first time at trial so long as a party has submitted any expert witness declaration whatsoever is inconsistent with this purpose. [T]he exclusion sanction of subdivision (j) applies when a party unreasonably fails to submit an expert witness declaration that fully complies with the content requirements of subdivision (f)(2), including the requirement that the declaration contain “[a] brief narrative statement of the general substance of the testimony that the expert is expected to give.” (Subd. (f)(2)(B).) This encompasses situations…in which a party has submitted an expert witness declaration, but the narrative statement fails to disclose the general substance of the testimony the party later wishes to elicit from the expert at trial. To expand the scope of an expert’s testimony beyond what is stated in the declaration, a party must successfully move for leave to amend the declaration under subdivision (k).” (Bonds, supra, 20 Cal.4th 148-149.

Motion to Exclude Areas of Testimony Not Disclosed in Expert Deposition

While this motion may be the most common expert in limine motion filed by litigants over the last 20 years, until the recent decision in Jones v. Moore, supra, there was little case authority supporting exclusion of such expert trial testimony beyond the deposition’s boundaries under § 2034(j). This naturally follows because none of the four provisions of § 2034(j) expressly addresses exclusion of expert opinion evidence not disclosed in deposition. In Jones, a legal malpractice case, Plaintiff’s “standard-of-care” expert represented in his deposition that he had expressed all of the opinions had planned on offering at trial, and that if he formed any new ones, we would notify the defendant. At trial, however, the expert sought to proffer several new opinions not previously disclosed, which were held properly excluded.

Relying on the Supreme Court’s reasoning in Bonds, supra, the Court observed that:

[u]nder these circumstances, exclusion of testimony going beyond the opinions he expressed during his deposition was justified. The purpose of section 2034 is to permit parties to adequately prepare to meet the opposing expert opinions that will be offered at trial. ‘[T]he need for pretrial discovery is greater with respect to expert witnesses than it is for ordinary fact witnesses [because] …. [ ] … the other parties must prepare to cope with witnesses possessed of specialized knowledge in some scientific or technical field. They must gear up to cross-examine them effectively, and they must marshal the evidence to rebut their opinions.’ (1 Hogan & Weber, Cal. Civil Discovery (1997) Expert Witness Disclosure, s 10.1, p. 525.) (Bonds v. Roy (1999) 20 Cal.4th 140, 147.) When an expert deponent testifies as to specific opinions and affirmatively states those are the only opinions he intends to offer at trial, it would be grossly unfair and prejudicial to permit the expert to offer additional opinions at trial….“The case before us does not turn on the adequacy of the expert witness declaration, but rather on a party’s right to rely on the other party’s expert’s express representation that the opinions expressed during an expert deposition are the only ones that need be met at trial. Bonds does however provide support for the result we reach because it recognizes that an important goal of section 2034 is to enable parties to properly prepare for trial, and ‘[a]llowing new and unexpected testimony for the first time at trial” is contrary to that purpose. (See, Id. at p. 148.) Jones, supra, 80 Cal.App.4th at 564-566.

In order to make this in limine motion, however, the adverse expert must specifically have been asked in his deposition whether he had expressed all of his opinions he intended to offer and asked to pledge that he would notify the adverse party if any new opinions were formed.

Motion to Exclude Opinions of Non-retained Experts Formed in Anticipation of Litigation

One motion in limine facilitated by the clarification of the retained vs. non-retained expert distinction in Schreiber would be the exclusion of any opinion testimony by experts designated as non-retained formed outside of their percipient work, e.g., a treating physician who, long after treating the patient, is asked to review records to reach new opinions for use at trial. As the Court in Schreiber pointed out, deposing percipient experts (e.g., treating physicians identified in interrogatories responses) at an early date and prior to expert witness designations is the best means of safeguarding against potential later prejudice and alleged unfair surprise in this regard.

Nonetheless, where a non-retained expert has clearly formed opinions concerning the litigation [s]he intends to offer at trial which clearly fall outside of his/her percipient duties, under Schreiber failure to have furnished the expert witness declaration as to that expert fully compliant with § 2034(f)(2) would appear to mandate exclusion of that non-retained expert’s opinions which exceed the scope of his or her percipient functions.

Motion to Exclude Improper Expert Opinion

Notwithstanding the broad range of subjects amenable to expert witness testimony “of assistance to the trier of fact,” (Evid.C. § 801), “there are limits to expert testimony, not the least of which is the prohibition against admission of an expert’s opinion on a question of law.” (See, Summers v. A.L. Gilbert Co. (1999) 69 Cal.App.4th 1155, 1178.) “The manner in which the law should apply to particular facts is a legal question and is not subject to expert opinion.” (Id., 69 Cal.App.4th at 1179, citing, Ferreira v. WCAB (1974) 38 Cal.App.3d 120, 125-126.) This is true “regardless of whether the opinion embraces an ultimate issue.” (See, Downer v. Bramet (1984) 152 Cal.App.3d 837, 839.) Experts are thus barred from offering opinions on the meaning of statutes or regulations. (People v. Torres (1995) 33 Cal.App.4th 37, 45-46 [experts’ interpretation of meaning or purpose of statute improper]; People v. Ochoa (1991) 231 Cal.App.3d 1413, 1422-1424 [expert’s testimony on meaning of governmental regulations improper]; Howard Jarvis Taxpayers Ass’n. v. City of Riverside (1999) 73 Cal.App.4th 679, 689 [expert’s opinion on the meaning, interpretation and/or application of Proposition 218 improper]. )

Similarly, expert opinion on the legal interpretation of contracts has also been found to be inadmissible and “inappropriate.” (Cooper Companies v. Transcontinental Ins. Co. (1995) 31 Cal.App.4th 1094, 1100; accord Devin v. United Services Auto. Assn. (1992) 6 Cal.App.4th 1149, 1158, fn. 5). )

Where an expert in deposition has attempted to offer opinion testimony concerning a statute, regulation, contract or other legal document, or has offered an opinion that such statute or regulation was violated, or such contract breached, any such opinion testimony would be and is properly excluded on an in limine motion.

Motion to Exclude Illegally Substituted “Supplemental” Expert

Frequently seen in practice are attempts to use the so-called “supplemental” expert witness designation procedure of § 2034(h) to substitute an expert in a certain field for one previously designated in the same field on the initial designation. Not infrequently, after one party receives the adversary’s designation identifying an expert perhaps superior in qualifications, credentials and/or experience to the expert originally designated, [s]he may thereafter attempt to “supplement” under C.C.P. § 2034(h) by identifying another expert in the same field as previously disclosed. This is an illegal substitution properly precluded by a motion in limine. See, Basham v. Babcock, supra, 44 Cal.App.4th 1717. “A party may submit a supplemental expert witness list within 20 days after the exchange, but only ‘if the party supplementing the expert witness list has not previously retained an expert to testify on that subject.’ (§2034, subd. (h).) It follows that a party who has designated an expert to testify on a particular subject may not use a supplemental list to substitute experts.” (Id., 44 Cal.App.4th at 1723.) To permit a supplementally-designated expert to render testimony on the same subject matter areas as an initially-designated expert “violate[s] the letter and spirit of section 2034.” (Id., 44 Cal.App.4th at 1723.)

Motion to Exclude Undesignated Alleged “Rebuttal” Expert Testimony

One of the most frequently misunderstood areas of expert testimony is undesignated expert “rebuttal” testimony. C.C.P. § 2034(m)(2) permits an expert witness to be called at trial “to impeach the testimony of an expert witness offered by any other party at trial.” However, the statute further cautions that: “This impeachment may include testimony to the falsity or non-existence of any fact used as the foundation for any opinion by any other party’s expert witness, but may not include testimony that contradicts the opinion.” (Ibid.)

All too frequently, however, parties will attempt to call a previously undesignated expert under the guise of “rebuttal” testimony, when in fact the real purpose is to contradict a properly-designated adversary’s expert’s opinion(s). The distinction between proper and improper undesignated expert rebuttal opinion evidence lies in the concept of foundational impeachment: an undesignated expert properly rebuts the properly-designated experts opinions which [s]he offers opinion evidence which impeaches one or more foundational facts relied upon by the properly designated adverse expert. (See, Fish v. Guevara (1993) 12 Cal.App.4th 142, 145-146, 15 Cal.Rptr.2d 329.) “When it comes to impeaching expert witnesses, the distinction between an opinion and a foundational fact– through arbitrary — must be made. In many cases, the ultimate opinion of the expert is based on a series of underlying opinions. Thus, rather than broadly construing what a foundational ‘fact’ is, the term should be strictly construed by the trial court to prevent a party from offering a contrary opinion of his expert under the guise of impeachment.” (Id.12 Cal.App.4th at 146, citing Kennemur v. State of California (1982) 133 Cal.App.3d 907, 924.)

Typical examples of a properly admitted undesignated rebuttal expert would be a document examiner whose testimony is offered to impeach the authenticity of documents upon which a designated expert has predicated his or her opinions, or an undesignated DNA expert’s testimony that impeaching the genuineness of tissue samples relied upon by a designated medical expert’s opinions.

Given the frequent potential for ambiguity over whether undesignated expert rebuttal testimony is on one hand contradiction (proscribed) versus impeachment of foundational facts (the proper purpose for undesignated rebuttal expert evidence), a proper in limine motion should be made to exclude any undesignated so-called rebuttal testimony which has any tendency to contradict any designated expert’s opinions, consonant with the rulings in Kennemur and Fish.

Motion to Exclude Recitation of Hearsay Under the Guise of “Expert” Testimony

Even where the experts are properly designated, it is all too common for parties to attempt to utilize the artifice of expert testimony to bootstrap into evidence two other kinds of improper evidence: (1) the out of court opinions of undesignated experts; and (2) the recitation of the contents of expert and percipient documentary hearsay. In point of fact, many litigants appear to plan their entire trial strategy under the assumption that their experts will bootstrap into evidence, under the guise of “expert opinion evidence”, wholesale reams of unauthenticated hearsay studies, reports, records, tests, and other documentary evidence and “matters” upon which the expert’s opinions are supposedly based. However, California law does not permit such tactics.

It is well-settled law that expert witnesses may not recite hearsay under the guise of expert opinion evidence. (See, e.g.,People v. Coleman, (1985) 38 Cal.3d 69, 92; Whitfield v. Roth (1974) 10 Cal.3d 874 [medical malpractice defense expert’s purported recitation of opinions of his colleagues who reviewed X-Ray films and likewise could detect no abnormalities held inadmissible hearsay]; Korsak v. Atlas Hotels, Inc., (1992) 2 Cal.App.4th 1516, 1522-1528 [hotel mechanical engineer’s recitation of outcome of telephonic survey of other hotel’s maintenance practices held inadmissible hearsay]; See, also, Continental Airlines v. McDonnell Douglas Corp., (1989) 216 Cal.App.3d 388, 416; Mosesian v. Pennwalt Corp. (1987) 191 Cal.App.3d 851, 860-862; Grimshaw v. Ford Motor Co., (1981) 119 Cal.App.3d 757, 788 [Plaintiff’s expert properly precluded from reciting the details of reports and studies supporting his opinion which were independently inadmissible hearsay]; People v. Piper, (1980) 103 Cal.App.3d 102, 122. ) Such experts testifying at trial “may not under the guise of reasons [supporting his or her opinion(s)] bring before the jury incompetent hearsay evidence.” (People v. Coleman, supra, 38 Cal.3d at 92.) The rationale for this rule largely lies in the absence of adequate cross-examination safeguards. (See, Whitfield v. Roth, supra, 10 Cal.3d at 895.) Moreover, while “[o]rdinarily, the use of a limiting instruction that matters on which an expert based his opinion are admitted only to show the basis of the opinion and not for the truth of the matter cures any hearsay problem involved,…[] in aggravated situations, where hearsay evidence is recited in detail, a limiting instruction may not remedy the problem. (Evid.C, §§ 352, 355; see Conservatorship of Buchanan, 78 Cal.App.3d 281, 289; Kelley v. Bailey, 189 Cal.App.2d 728, 738; see, also, Adkins v. Brett, 184 Cal. 252, 258.” (Grimshaw, supra, 119 Cal.App.3d at 687-688.)

A motion in limine should be prepared following the expert’s deposition seeking the exclusion of all such hearsay matters referenced by the expert on the grounds that a limiting instruction would be futile, since in most such instances, the experts has typically asserted these hearsay documents and out–of-court opinions for no purpose other than for the truth of the matter asserted under the guise of “opinions.” This essentially asks the trier of fact to adopt the “opinion” of the hearsay declarant as support for, in amplification of, or as the sole giver of the live-witness’s opinion testimony.

In addition, a motion in limine should be directed at excluding any objected-to documentary evidence sponsored by experts and proffered into evidence, such as texts, treatises, published studies, reports, etc., which likewise remains inadmissible hearsay regardless of the credentials of the expert claiming to rely upon them. It is well-settled California law that such learned treatises, texts, journal articles, and publications are rank hearsay and are independently inadmissible at trial. (Luque v. McClean (1972) 8 Cal.3d 136, 147-148; Gallagher v. Market St. Ry. Co., (1885) 67 Cal.13, 15; Baily v. Kreutzmann, (1904) 141 Cal. 519, 521; Los Angeles City Ethics Committee v. Superior Court (1992) 8 Cal.App.4th 1287, 1292, fn.2; Gluckstein v. Lipsett, (1949) 93 Cal.App.2d 391, 401; People v. Conrad, (1973) 31 Cal.App.3d 308, 321; Intoximeters v. Younger, (1975) 53 Cal.App.3d 262, 272.) In Conrad, supra, for example, exclusion of the popular Physician’s Desk Reference [“PDR”] offered to show the risks and side effects of drugs administered to the defendant was held proper as the PDR, authoritative as it may have been regarded in the medical community, nonetheless was still inadmissible hearsay as a matter of law. And in Intoximeters, the Court specifically rejected the use of the contents of medical articles in scholarly medical journals as hearsay, and noting further that: “[e]xperience has shown that isolated reports of this nature are often as not rebutted by the opinions and experiences of other writers, and that they are unreliable as proof.” (Id., 53 Cal.App.3d at 272. [Emphasis added.]) In Luque, the Supreme Court held that a public safety booklet published by the U.S. Government’s Department of Health, Education and Welfare containing a statistical survey of lawnmower accidents was inadmissible hearsay. And in Los Angeles City Ethics Committee, the Court reiterated long-settled law that newspaper articles are likewise inadmissible hearsay. (See, also, Tibbetts v. Van de Kamp (1990) 222 Cal.App.3d 389, 395, fn. 5, and Stoneking v. Briggs (1967) 254 Cal.App.3d 563, 576.)

Motion to Exclude “Expert” Testimony re Causation to Extent of Less than a Probability

Evidence of causation of injury must rise to the level of a reasonable probability based upon competent expert testimony. (See, Budd v. Nixen, (1971) 6 Cal.3d 195, 200; Bromme v. Pavitt, (1992) 5 Cal.App.4th 1487, at 1498; Cottle v. Superior Court (1992) 3 Cal.App.4th 1367, 1384-1385; Dumas v. Cooney (1991) 235 Cal.App.3d 1593, 16; Jones v. Ortho Pharmaceutical Corp., (1985) 163 Cal.App.3d 396.) This follows, because whether a particular instrumentality had any tendency in reason medically, pharmacologically or therapeutically to affect a person’s conduct or behavior under any particular set of circumstances is clearly “related to a subject that is sufficiently beyond common that the opinion of an expert would assist the trier of fact.” (See, Evid.C. § 801.) Even in simple auto collision cases, it is settled that causation cannot be established without expert testimony “because ‘…expert or special knowledge is essential to the formation of an intelligent opinion which would be of aid to the jury…[Thus] [a] nonexpert witness cannot express his opinion as to the cause of a particular accident.’” (Visueta v. General Motors, (1991) 234 Cal.App.3d 1609, at 1616.)

The law is well settled that in a personal injury action causation must be proven within a reasonable medical probability based upon competent expert testimony. Mere possibility alone is insufficient to establish a prima facie case. case. (Morgenroth v. Pacific Medical Center, supra, 54 Cal.App.3d at p. 533, 126 Cal.Rptr. 681; [163 Cal.App.3d 403] Johnston v. Brother (1961) 190 Cal.App.2d 464, 473, 12 Cal.Rptr. 23; Pacific Employers Insurance Co. v. Industrial Accident Commission (1960) 182 Cal.App.2d 162, 165, 5 Cal.Rptr. 738.) That there is a distinction between a reasonable medical “probability” and a medical “possibility” needs little discussion. There can be many possible “causes,” indeed, an infinite number of circumstances which can produce an injury or disease. A possible cause only becomes “probable” when, in the absence of other reasonable causal explanations, it becomes more likely than not that the injury was a result of its action. This is the outer limit of inference upon which an issue may be submitted to the jury. (See Parker v. Employers Mutual Liability Ins. Co. of Wisconsin (Tex.1969) 440 S.W.2d 43, 47.)” (Id., 163 Cal App.3d at 402-403 [emphasis supplied].)

The minimum threshold of “reasonable probability test” applicable to causation issues in personal injury actions has also recently been extended to virtually every other form of tort action in California. (See, Leslie G. v. Perry & Associates, (1996) 43 Cal.App.4th 472, 488 [”a tenant’s negligence action against landlord must be supported by evidence establishing that it was more probable than not that, but for the landlord’s negligence, the assault would not have occurred”]; Rutherford v. Owens-Illinois, Inc., (1997) 16 Cal.4th 1008A, 977; Lineaweaver v. Plant Insulation Co., (1995) 31 Cal.App.4th 1409, 1416. [applying standard to asbestos negligence cases].)

All of this means that where an adverse causation expert has testified in his deposition that he cannot state that a cause of an injury-producing event was more probably than not, his testimony becomes inadmissible speculations as to mere “possibilities,” and that causation opinion is properly excluded on an in limine motion. (See, Jones, Morganroth)

Motion to Exclude “Expert” Testimony Based on Facts Not in Evidence, Facts Contrary to Those in Evidence, and Speculation

The California Supreme Court has declined to adopt the federal gatekeeping standard of Daubert v. Merrill Dow Pharmaceuticals, Inc. (1993) 509 U.S. 579, 113 S.Ct. 2786. (See, People v. Leahy (1994) 8 Cal.4th 587.) However, it remains well-settled law that an expert nonetheless may not base his/her opinion on speculation or conjecture. (Smith v. ACandS, Inc., (1994) 31 Cal.App.4th 77, 93.) Nor may the expert base his or her opinion on unproven facts. (See, Hyatt v. Sierra Boat Co., (1978) 79 Cal.App.3d 325, 338.) Nor may an expert base his opinion on assumptions of fact based on insufficient data. (Blecker v. Wolbart, (1985) 167 Cal.App.3d 1195, 1205; Richard v. Scott, (1978) 79 Cal.App.3d 57.) It is equally established that the expert also may not base an opinion on facts which are contrary to the evidence and/or which ignore the evidence. (Hyatt, supra, 79 Cal.App.3d at 338; Estate of Powers, (1947) 81 Cal.App.2d 480.) “It is well-settled that an expert’s assumption of facts contrary to the proof destroys the opinion.” (Hyatt, supra, 79 Cal.App.3d at 338, citing, Winthrop v. Indust. Accid. Comm., (1931) 213 Cal. 351, 354-355.)

As a practical matter, while it is difficult to get an in limine motion granted at the outset of trial, based on the opposing expert’s basis of his or her opinions on facts not in evidence and/or upon facts contrary to the evidence, where the circumstances as adduced from the expert’s deposition are egregious or the opinions unusually facially preposterous the motion should certainly be made. Moreover, the fact that the Court in Jones v. Moore decreed that no expert’s opinion not revealed in deposition may be used at trial means that there is little an expert may resort to at trial not previously disclosed in his deposition. Accordingly, it is difficult to defend an outrageous opinion contrary to facts in evidence and/or based upon facts not in evidence based on the notion that there may be other evidence not previously disclosed in deposition to rehabilitate an otherwise unfounded opinion.

At the very least, even in a case of a closer call, such a motion in limine should at least be made in the alternative as a motion for an Evidence Code § 402 examination of the expert at the time of his or her testimony, to give the judge notice and some information to begin thinking about the issues in question before an ultimate admissibility decision must finally be made.

Motion to Exclude Cross-Examination of Expert Based on Materials Not Read, Considered or Relied Upon

Another tactic often used by adverse counsel is to show the expert new articles, treatises, journals and other published materials the expert may never previously even have been aware of, for the purposes of laying a foundation to elicit favorable answers to hypothetical questions assuming the truth of the newly supplied materials. This is generally prohibited by Evid.C. § 721(b), which precludes such cross-examination unless that witness has referred to, considered, or relied upon such publication in arriving at or forming his or her opinions, the publication in question has been admitted into evidence (difficult given its hearsay character), or it has been established by expert testimony or judicial notice as reliable. Where an expert has been so confronted in deposition by the adverse party with such new matters, an obvious problem arises if the expert is asked to review an article and thereafter asked questions on it, since (s)he will then have “reviewed” the matter. This is perhaps the only circumstance where it is proper either to instruct a witness not too review the matter, or to adjourn the deposition and seek a protective order. Where it is suspected that the same tactic may be used at trial before the jury, the motion in limine should be made prophylactically in advance.

Concluding Thoughts

The Court in Kelly v. New West Federal Savings, supra, emphasized certain minimal guidelines for the proper use of in limine motions, largely out of the perception that in actual practice, they have become a tool of abuse, particularly by the defense. (Id., 49 Cal.App.4th at 669.) Other courts have voiced similar concerns, particularly with the inappropriate use of in limine motions as improper substitutes for summary judgment which lack adequate procedural due process safeguards. (See, e.g., Cottle v Superior Court (1992) 3 Cal.App.3d 1367, 1383-1384.) As such, they are best used surgically and judiciously, and not as a bludgeon, if for no other reason than out of the expectation that the typical trial judge may have short attention span on the first day of a new trial. Most such trial judges seem to adhere to the belief that “until the evidence is actually offered, and the court is aware of its relevance in context, its probative value, and its potential for prejudice, i.e., matters related to the state of the evidence at the time an objection is made, the court cannot intelligently rule on admissibility.” (See, People v. Jennings (1988) 46 Cal.3d 963, 975, fn. 3.)

Therefore, pick the battles worth fighting at the outset of the case. When electing to make such a motion related to expert witness testimony, it should be thoroughly supported by adequate declaration evidence, accompanied by properly authenticated expert designation and expert deposition transcript evidence. Remember the admonition of Kelly: “Motions in limine, to the extent that they rely upon a factual foundation, are no different than any other pretrial motion and must be accompanied by appropriate supporting documents. Absent an appropriate factual showing to support the motion, the court should not entertain the motion.” (Id., 49 Cal.App.4th 671, fn. 3.)

In sum and above all, where an expert evidentiary issue is determined of sufficient consequence to warrant filing an in limine motion in the first place, never more true is the adage that “a job worth doing is worth doing well.”