Iowa Code § 709A.4: Preliminary examination.

If, in proceedings in juvenile court, it appears probable that an indictable offense has been committed and that the commission thereof caused, or contributed to, the delinquency or dependency of such a child, said court may order the issuance of a warrant for the arrest of such suspected person, and on the appearance of such person said court may proceed to hold a preliminary examination, and in so doing shall exercise all the powers of a committing magistrate.