Missouri lawyer research helps, and links for research, regarding state law on various topics, which may include information regarding expert witnesses, legal malpractice, and legal ethics.

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An Advisory Committee issues the state's formal opinions.  Opinions through June 30, 1994 were included in a desk book entitled Missouri Advisory Opinions but the book is no longer being published. There is an updated electronic  version of the desk book. 

The basic standard regarding expert witness testimony in Missouri is discussed in State Board of Registration for the Healing Arts v. McDonagh, 123 S.W.3d 146 (Mo.banc) [The relevant standard for evaluating the admissibility of expert testimony in civil cases is that set forth in section 490.065, RSMo, (reaffirming Lasky v. Union Electric Co., 936 S.W.2d 797 (Mo. banc 1997)].  The court's opinion states, in part:

" Court en banc holds: (1) The relevant standard for evaluating the admissibility of expert testimony in civil cases is that set forth in section 490.065, RSMo, (reaffirming Lasky v. Union Electric Co., 936 S.W.2d 797 (Mo. banc 1997)). To the extent that civil cases decided since Lasky apply the test set forth in Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) (stating that, for expert testimony to be admissible, the basis underlying the expert's opinion must be sufficiently established to have gained general acceptance in the particular field), or some other standard, they are incorrect and should not be followed.

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(3) The section 490.065 standard is very similar to that initially adopted by the federal courts in Daubert v. Merrell Dow Pharmaceuticals, Inc., 59 U.S. 579 (1993), and set out in federal rule of evidence 702. Section 490.065.3, however, has important differences when compared to federal rule of evidence 703. Neither Daubert nor FRE 703 require experts to identify the relevant scientific community, or field, in which the data and facts are accepted. On the other hand, section 490.065.3 expressly requires a showing that the facts and data upon which the expert relies are of a type reasonably relied on by experts in the field in forming opinions or inferences on the subject of the expert's testimony. It also requires the courts to make an independent assessment as to whether the methodology is otherwise reasonably reliable.

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(5) Nothing in the section 490.065.3 standard, however, requires the expert's conclusions to be in conformity with the medical consensus or to be accepted generally. As under Daubert and its progeny, such acceptance is but one factor in the relevant inquiry. If the facts and data used by the expert are not of a type reasonably relied on by experts in the field, or if the methodology is otherwise not reasonably reliable, then the testimony does not meet the statutory standard and is inadmissible."

The elements of a legal malpractice action in Missouri, as it is usually stated [e.g., Donahue v. Shughart, Thomson & Kilroy, P.C., 900 S.W.2d 624, 626 (Mo. banc 1995)] is that a client must prove:

(1) that an attorney-client relationship existed;

(2) that the attorney acted negligently [failed to exercise that degree of skill and diligence ordinarily used under the same or similar circumstances by members of the legal profession. London v. Weitzman, 884 S.W.2d 674, 677 (Mo. App. 1994)] or in breach of contract;

(3) that such acts were the proximate cause of the client's damages; and

(4) that but for attorney's conduct the result of the underlying action or proceeding would have been different. [Mogley v. Fleming , 11 S.W.3d 740, 747 (Mo. App. 1999); Steward v. Goetz, 945 S.W.2d 520, 532 (Mo. App. 1997); Baldridge v. Lacks, 883 S.W.2d 947, 954 (Mo. App. 1994)].

As to point (2) above: note that Missouri case decisions [e.g., Klemme v. Best, 941 S.W.2d 493, 495 (Mo. banc 1997] have spoken of two possible foundations for a legal malpractice action to wit: "is founded on an attorney's duty to exercise due care or to honor express contract commitments." Id.

As to point (3) above, foreseeability is a prominent factor in the proximate cause analysis. Krause v. U.S. Truck Co., Inc., 787 S.W.2d 708, 710 (Mo. banc 1990).

As to point (4) above, after determining that there was damage, then "The measure of damage would be the amount a client would have received 'but for' the attorney's negligence." Steward v. Goetz, 945 S.W.2d 520, 532 (Mo. App. 1997)

Input of judge, jury and expert: notes.

In some instances, e.g., whether a summary judgment motion would have succeeded, there is a question whether the judge or a jury should determine whether an act is malpractice. A discussion is found in Flavan v. Cundiff, 83 S.W.3d 18 (Mo.App. W.D. 2002).