An ex post facto claim is proper where the prosecutor failed to establish that a sentencing statute was in effect at the time of the defendant’s crimes. A defendant may be convicted of child molestation based on generic testimony that is not specific as to dates. Where such testimony fails to establish the timing of the various acts, serious problems may arise regarding the ex post facto application of newly enacting sentencing statutes. The court here held that in such a case, the prosecution bears the burden of proving to the jury that the offenses occurred after the date of the relevant statutes, and where the evidence does not establish that fact, the defendant is entitled to sentencing under the earlier statutory scheme.