(2) As used in this section, an "accomplice" means a witness in a criminal action who, according to the evidence adduced in the action, is criminally liable for the conduct of the defendant under ORS 161.155 and 161.165, or, if the witness is a juvenile, has committed a delinquent act, which, if committed by an adult, would make the adult criminally liable for the conduct of the defendant. [Formerly 136.550]