Why are witness examinations usually conducted orally in court?

Witness examinations are conducted orally in court because oral proceedings are a fundamental, widely accepted standard in modern legal systems, having largely replaced the written proceedings that were favored during the Middle Ages.1

The preference for oral testimony is closely linked to the principle of direct interrogation, which is essential for the "free consideration of evidence" by the court. In the Anglo-American adversary system, oral examination and cross-examination allow opposing parties to test the reliability of testimony, as skillful questioning can reveal contradictions or modify the meaning of statements made during direct examination.123

Furthermore, the jury system has significantly influenced this practice. Oral proceedings, combined with direct interrogation and public trial, are considered vital for ensuring due process and protecting the jury from being misled by potentially unreliable or misinterpreted evidence. While some jurisdictions permit written statements in specific, limited circumstances, the oral interrogation of witnesses remains the primary method for establishing the truth in both common-law and civil-law traditions.1