Snook

Driving a vehicle while under the influence of alcohol or drugs is a misdemeanor. (Veh. Code, § 23152; see id., §§23160, 23165, 23170; all further statutory references are to the Vehicle Code unless otherwise noted.) Driving under the influence (DUI) may be charged as a felony rather than a misdemeanor when the offense occurs within seven years of three or more separate DUI violations which resulted in convictions. (§ 23175, subd. (a); hereafter section 23175(a).)

In this case we decide what happens when DUI convictions do not follow the chronological sequence in which the offenses were committed. Does the enhanced penalty still apply when the conviction for the first offense comes last? And if the increased penalty is imposed, would it violate the ex post facto clauses of the state and federal Constitutions?

We conclude the Legislature intended to subject repeat DUI offenders to enhanced penalties regardless of the order in which the offenses were committed and the convictions obtained, and the imposition of such a penalty does not violate any constitutional prohibition against ex post facto laws. Accordingly, the judgment of the Court of Appeal is reversed.

I. Facts…