(e) Proof of prior adjudications. No evidence or other disclosure of prior adjudications shall be presented to the court or jury during any adjudicatory hearing provided for under this Section unless otherwise permitted by the issues properly raised in such hearing. In the event the minor who is the subject of these proceedings elects to testify on his or her own behalf, it shall be competent to introduce evidence, for purposes of impeachment, that he or she has previously been adjudicated a delinquent minor upon facts which, had he been tried as an adult, would have resulted in his conviction of a felony or of any offense that involved dishonesty or false statement. Introduction of such evidence shall be according to the rules and procedures applicable to the impeachment of an adult defendant by prior conviction.
After an admission of the facts in the petition or adjudication of delinquency, the State's Attorney may file with the court a verified written statement signed by the State's Attorney concerning any prior adjudication of an offense set forth in subsection (a) of this Section which offense would have been a felony or of any offense that involved dishonesty or false statement had the minor been tried as an adult.
The court shall then cause the minor to be brought before it; shall inform him or her of the allegations of the statement so filed, and of his or her right to a hearing before the court on the issue of such prior adjudication and of his right to counsel at such hearing; and unless the minor admits such adjudication, the court shall hear and determine such issue, and shall make a written finding thereon.
A duly authenticated copy of the record of any such alleged prior adjudication shall be prima facie evidence of such prior adjudication or of any offense that involved dishonesty or false statement.
Any claim that a previous adjudication offered by the State's Attorney is not a former adjudication of an offense which, had the minor been prosecuted as an adult, would have resulted in his conviction of a felony or of any offense that involved dishonesty or false statement, is waived unless duly raised at the hearing on such adjudication, or unless the State's Attorney's proof shows that such prior adjudication was not based upon proof of what would have been a felony.