Witness Competence/Capacity to Testify

Though not as common as a case challenging someone’s capacity (e.g., guardianship, capacity to sign a will/trust/contract), pretty much any type of case in litigation can involve a question over the capacity of a witness to testify in court under oath.

Missouri presumes that a witness may competently testify, except a number of statutory exceptions including mental capacity. Cardenas v. Dir. of Revenue, 339 S.W.3d 608, 612 (Mo. Ct. App. 2011). If there is a challenge to witness competency, the witness legally has capacity to testify if (1) there is a present understanding of, or the ability to understand upon instruction, the obligation to speak the truth; (2) the capacity to observe the occurrence about which testimony is sought; (3) the capacity to remember the occurrence about which testimony is sought; and (4) the capacity to translate the occurrence into words. State v. Robinson, 835 S.w.2d 303, 307 (Mo. 1992).

A trial court judge has wide discretion in ruling on witness competency, and objections to competency are waived if not waived at the “earliest possible time.” State v. Hastings, 477 S.W.2d 108, 111 (Mo. 1972).