The trial of inmates escaping from a state or county correctional institution shall take place in the superior court of the county in which the escape occurs, and inmates so escaping shall remain in the correctional institution after their apprehension and shall be treated as are other inmates until the trial takes place. At the trial, the copies of the records transmitted to the superintendent or warden of the state or county correctional institution, relative to the former trials of such inmates, shall be produced and filed of record in the superior court; and any other inmate not included in the same indictment shall be a competent witness.