Weil v. Seltzer
United States Court of Appeals for the District of Columbia Circuit
873 F.2d 1453 (D.C. Cir. 1989)
After Weil died from illness linked to long-term steroid use his doctor, Seltzer (defendant), had prescribed for 20 years while calling it antihistamines, Weil's estate (plaintiff) sued and, during discovery, learned Seltzer had similarly mislabeled steroids for other patients; the district court admitted five former patients' testimony under Rule 406 as evidence of Seltzer's habitual practice, and ruled for the estate. Seltzer appealed the admission of that testimony.
Whether testimony regarding a person's habitual practice is admissible under Federal Rule of Evidence 406 when the witness lacks personal knowledge of the habit itself, having knowledge only of a single instance involving the witness.