Cal. Welf. & Inst. Code § 1732.7

A person who is convicted of a public offense for which the maximum penalty provided by law is imprisonment for not more than 90 days, and who is found to be less than 21 years of age at the time of his apprehension, may be committed to the Authority only if it is brought to the court’s knowledge that the person has been previously convicted of a public offense or has been a ward of the juvenile court by reason of a public offense and the court is satisfied that society will best be protected by commitment to the Authority.