A witness in criminal proceedings refers to a person who knows the case outside the proceedings and outside the parties. A witness refers to a person who has no interest in the case and is invited by the judicial organ to observe and supervise the execution of the lawsuit according to the needs of handling the case, and can testify when necessary.
Legal basis: Article 62 of the Criminal Law. Anyone who knows the case has the obligation to testify.
A person who is physically and mentally defective or young, can't distinguish right from wrong and can't express correctly, can't be a witness.