An offense prosecuted in the Superior Court which may be punished by death shall be prosecuted by indictment returned by a grand jury. An offense which may be punished by imprisonment for a term exceeding one year shall be prosecuted by indictment, but it may be prosecuted by information if the defendant, after he has been advised of the nature of the charge and of his rights, waives in open court prosecution by indictment. Any other offense may be prosecuted by indictment or by information. An information subscribed by the proper prosecuting officer may be filed without leave of court.