Section 344.1. Rules of evidence; proof of previous conviction or delinquency finding

1. If in  the  course  of  a  juvenile  delinquency
  proceeding,  any  witness,  including  a  respondent,  is properly asked
  whether he was previously convicted of a specified offense  and  answers
  in  the negative or in an equivocal manner, the party adverse to the one
  who called him may independently prove such conviction. If  in  response
  to  proper inquiry whether he has ever been convicted of any offense the
  witness answers in the negative or in an equivocal manner,  the  adverse
  party may independently prove any previous conviction.
    2.  If  a respondent in a juvenile delinquency proceeding, through the
  testimony of a witness other  than  respondent  called  by  him,  offers
  evidence of his good character, the presentment agency may independently
  prove  any previous finding of delinquency of the respondent for a crime
  the commission of which would tend to  negate  any  character  trait  or
  quality attributed to the respondent in such witness' testimony.