Rupert v. People
Supreme Court of Colorado
429 P.2d 276 (1967)
Colorado (plaintiff) charged Rupert (defendant) with kidnapping, and Rupert pleaded not guilty by reason of insanity, triggering a separate sanity trial. Durham, a lay witness who knew Rupert, testified about the specific acts, conduct, and conversation he observed that led him to believe Rupert was sane, while Rupert's expert witness testified Rupert was insane. The jury found Rupert sane, and a separate jury then convicted him of kidnapping; Rupert appealed, arguing the sanity-trial judge erred by admitting Durham's lay opinion testimony and by refusing to direct a verdict of insanity.
Whether a lay witness's opinion on a criminal defendant's sanity is admissible if the witness knows the defendant and testifies to the acts, conduct, and conversation underlying that opinion.