This article will explore the subject matter of impeachment of expert witnesses by the use of medical or scientific literature containing contrary opinions during cross-examination. The expert must first concede that the author or work is "authoritative" on the subject matter at issue. This foundation is often magical, elusive and frustrating to elicit from the opposing expert who typically will not want to concede that any treatise or work is authoritative thereby denying an effective means of cross-examination. This article reviews the various circumstances and use of "authoritative" literature during cross-examination of experts. As such literature is generally considered inadmissible hearsay evidence for the truth of the matter stated, violations of this rule by opposing counsel have led to reversal of jury verdicts. See Mark v. Colgate, 53 A.D.2d 884 (1st Dep't 1976); Labate v. Plotkin, 195 A.D.2d 444 (2d Dep't 1993); Watkins v. Labiak, 6 A.D.3d 426 (2d Dep't 2004). Various definitions and suggested language to establish an adequate foundation will be discussed. The Federal Rules of Evidence, which provide a more liberal use of learned treatises, will also be discussed.

Appellate Case Law

In the seminal case of Egan v. Dry Dock, East Broadway and Battery Railroad Company,12 A.D. 556 (1896), the First Department permits the cross-examination of the  defense expert by use of statements in two books on the subject of design, construction and operation of boilers which books the expert knew and admits were standard works on engineering subjects.

The court explained: