(a) All cases under the provisions of this chapter shall be heard at a special or separate session of the court, and no other matter shall be heard at that session. Except as provided in subdivision (b), no person on trial, awaiting trial, or under accusation of crime, other than a parent, guardian, or relative of the minor, shall be permitted to be present at any such session, except as a witness.
(b) Hearings for two or more minors may be heard upon the same rules of joinder, consolidation, and severance as apply to trials in a court of criminal jurisdiction.