Hypothetically Speaking . . .

"Johnny" was adopted from a Third World orphanage as a young child and given an estimated birth date by his Californian parents. He is tried and convicted as a minor in juvenile court for a first degree burglary committed on the eve of his eighteenth birthday. Shortly after the trial, Johnny undergoes "bone age" tests, which conclusively prove that Johnny was in fact at least nineteen when he committed the burglary.

What happens next?