Where petitions have been filed which allege that one or more children were involved in the commission of the same delinquent act or acts, the children shall be tried jointly unless either:
(1) The state elects to try them separately.
(2) The court, on motion of the child and after contradictory hearing with the district attorney, is satisfied that justice requires a severance.
Acts 1991, No. 235, §8, eff. Jan. 1, 1992.