California Code, Penal Code - PEN § 6

No act or omission, commenced after twelve o'clock noon of the day on which this Code takes effect as a law, is criminal or punishable, except as prescribed or authorized by this Code, or by some of the statutes which it specifies as continuing in force and as not affected by its provisions, or by some ordinance, municipal, county, or township regulation, passed or adopted, under such statutes and in force when this Code takes effect.  Any act or omission commenced prior to that time may be inquired of, prosecuted, and punished in the same manner as if this Code had not been passed.