Castillero

*395 The district attorney charged appellant Donovan Castillero in juvenile court with a number of serious sexual offenses. The juvenile court found him unfit for juvenile adjudication and transferred the matter to a court of criminal jurisdiction. 1 In adult/criminal court, Castillero pleaded guilty to four crimes and agreed to serve 40 years in prison. Prior to sentencing, the trial court denied Castillero's request that his case be transferred back to juvenile court for a transfer hearing pursuant to the procedures set out in Proposition 57, which the electorate passed after Castillero's original hearing in juvenile court.

We conclude that the adult/criminal court erred in not transferring the case back to juvenile court for a post-Proposition 57 transfer hearing, and we vacate the judgment and order all counts of conviction transferred to juvenile *396 court. For the benefit of the juvenile court after transfer, we detail how the court should proceed upon each count of conviction.

I. FACTS AND PROCEDURAL BACKGROUND

The facts of Castillero's crimes are largely not relevant to this appeal. In a juvenile wardship petition filed in May 2015 under Welfare and Institutions Code…