§ 343.5. Rules of evidence; impeachment of own witness by proof of
prior contradictory statement. 1. When, upon examination by the party
who called him, a witness in a delinquency proceeding gives testimony
upon a material issue of the case which tends to disprove the position
of such party, such party may introduce evidence that such witness has
previously made either a written statement signed by him or an oral
statement under oath contradictory to such testimony.

2. Evidence concerning a prior contradictory statement introduced
pursuant to subdivision one may be received only for the purpose of
impeaching the credibility of the witness with respect to his testimony
upon the subject, and does not constitute evidence in chief.

3. When a witness has made a prior signed or sworn statement
contradictory to his testimony in a delinquency proceeding upon a
material issue of the case, but his testimony does not tend to disprove
the position of the party who called him and elicited such testimony,
evidence that the witness made such prior statement is not admissible,
and such party may not use such prior statement for the purpose of
refreshing the recollection of the witness in a manner that discloses
its contents to the court.